KIMURA Yuichi

Researcher Information

Degree

• Dr. of Engineering（1991/03）
• Dr. of Medical Science（2001/05）

J-Global ID

• 200901064142666290

Research Interests

• PET   positron emission tomography   陽電子断層像   AI   kinetics analysis   医用画像   動態解析   コンパートメントモデル   核医学   分子イメージング   molecular imaging   nuclear medicine   

Research Areas

• Life sciences / Radiology
• Life sciences / Radiology
• Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Measurement engineering
• Life sciences / Medical systems
• Life sciences / Biomaterials
• Life sciences / Biomedical engineering

Academic & Professional Experience

• 2022/04 - Today  Kindai UniversityFaculty of InformaticsProcessor
• 2021/01 - Today  Kindai UniversityCyber Informatics Research Institute教授
• 2017/10 - Today  Yokohama City University医学部 生理学教室客員教授
• 2013/05 - Today  Fujita Health University医学部 放射線医学教室客員教授
• 2013/04 - 2022/03  Kindai UniversityDepartment of Computational Systems Biology, Faculty of Biology-Oriented Science and TechnologyProfessor
• 2007/04 - 2022/03  Tokyo Metropolitan Geriatric Hospital and Institute of GerontologyResearch Team for Neuroimaging非常勤研究員
• 2007/04 - 2013/03  National Institute of Radiological Sciences分子イメージング研究センターチームリーダー, 室長
• 1999/09 - 2007/03  東京都老人総合研究所ポジトロン医学研究部門主任研究員
• 1999/02 - 1999/08  Tokyo Medical and Dental University医用器材研究所 計測機器研究部門助教授
• 1994/08 - 1999/01  Tokyo Medical and Dental University医用器材研究所 計測機器研究部門助手
• 1999  Senior research scientist, Tokyo Metropolitan
• 1999  Associate Professor, Institute for Medical and
• 1991/04 - 1994/07  Nihon UniversityCollege of Industrial Technology助手
• 1994  Research associate, Institute for Medical and
• 1988/04 - 1991/03  Waseda UniversitySchool of Science and Engineering助手
• 1991  Research associate, School of Industrial Engineering,
• 1988  Research associate, School of Science and Engineering,
• Institute of Gerontology
• Dental Engineering, Tokyo Medical and Denial University
• Dental Engineering, Tokyo Medical and Dental University
• Nihon University
• Waseda University

Education

• 1984/04 - 1989/03  Waseda University  Graduate School of Science and Engineering  電気工学専攻
• 1980/04 - 1984/03  Waseda University  School of Science and Engineering  電子通信学科
• 1976/04 - 1979/03  国立金沢大学教育学部附属高等学校
•        -   Waseda University
•        -   Graduate School of Waseda University

Association Memberships

• 米国核医学会   日本電子情報通信学会   日本核医学会   日本生体医工学会   国際バイオテレメトリ学会   IEEE   The Society of Instrument and Control Engineers   The Japanese Society of Physical Fitness and Sports Medicine   Information and Communication Engineering   The Institute of Electronics   The Institute of Electrical and Electronics Engineering   Society of Nuclear Medicine   Japan Society of Nuclear Medicine   Japan Society of Medical and Biological Engineering   International Society of Biotelemetry   

Published Papers

• AI prediction of extracorporeal shock wave lithotripsy outcomes for ureteral stones by machine learning-based analysis with a variety of stone and patient characteristics

  Yukako Nakamae; Ryusuke Deguchi; Mitsutaka Nemoto; Yuichi Kimura; Shimpei Yamashita; Yasuo Kohjimoto; Isao Hara

  Urolithiasis Springer Science and Business Media LLC 52 (1) 1 - 8 2023/12 [Refereed]
  
• てんかん病態を制御する脳内AMPA受容体の動態

  永露 毅; 宮崎 智之; 波多野 真依; 中島 和希; 有澤 哲; 高田 由貴; 木村 キミト; 野田 賀大; 内田 裕之; 木村 裕一; 高橋 琢哉

  核医学技術 (NPO)日本核医学技術学会 43 (予稿集) 321 - 321 0289-100X 2023/10
• Unsupervised Feature Extraction for Various Computer-Aided Diagnosis Using Multiple Convolutional Autoencoders and 2.5-Dimensional Local Image Analysis

  Mitsutaka Nemoto; Kazuyuki Ushifusa; Yuichi Kimura; Takashi Nagaoka; Takahiro Yamada; Takeharu Yoshikawa

  Applied Sciences MDPI AG 13 (14) 8330 - 8330 2023/07 [Refereed]
   

  There are growing expectations for AI computer-aided diagnosis: computer-aided diagnosis (CAD) systems can be used to improve the accuracy of diagnostic imaging. However, it is not easy to collect large amounts of disease medical image data with lesion area annotations for the supervised learning of CAD systems. This study proposes an unsupervised local image feature extraction method running without such disease medical image datasets. Local image features are one of the key determinants of system performance. The proposed method requires only a normal image dataset that does not include lesions and can be collected easier than a disease dataset. The unsupervised features are extracted by applying multiple convolutional autoencoders to analyze various 2.5-dimensional images. The proposed method is evaluated by two kinds of problems: the detection of cerebral aneurysms in head MRA images and the detection of lung nodules in chest CT images. In both cases, the performance is high, showing an AUC of more than 0.96. These results show that the proposed method can automatically learn features that are useful for lesion recognition from lesion-free normal data, regardless of the type of image or lesion.
• Dynamics of AMPA receptors regulate epileptogenesis in patients with epilepsy.

  Tsuyoshi Eiro; Tomoyuki Miyazaki; Mai Hatano; Waki Nakajima; Tetsu Arisawa; Yuuki Takada; Kimito Kimura; Akane Sano; Kotaro Nakano; Takahiro Mihara; Yutaro Takayama; Naoki Ikegaya; Masaki Iwasaki; Akitoyo Hishimoto; Yoshihiro Noda; Takahiro Miyazaki; Hiroyuki Uchida; Hideaki Tani; Nobuhiro Nagai; Teruki Koizumi; Shinichiro Nakajima; Masaru Mimura; Nozomu Matsuda; Kazuaki Kanai; Kazuhiro Takahashi; Hiroshi Ito; Yoji Hirano; Yuichi Kimura; Riki Matsumoto; Akio Ikeda; Takuya Takahashi

  Cell reports. Medicine 4 (5) 101020 - 101020 2023/04 [Refereed]
   

  The excitatory glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs) contribute to epileptogenesis. Thirty patients with epilepsy and 31 healthy controls are scanned using positron emission tomography with our recently developed radiotracer for AMPARs, [11C]K-2, which measures the density of cell-surface AMPARs. In patients with focal-onset seizures, an increase in AMPAR trafficking augments the amplitude of abnormal gamma activity detected by electroencephalography. In contrast, patients with generalized-onset seizures exhibit a decrease in AMPARs coupled with increased amplitude of abnormal gamma activity. Patients with epilepsy had reduced AMPAR levels compared with healthy controls, and AMPARs are reduced in larger areas of the cortex in patients with generalized-onset seizures compared with those with focal-onset seizures. Thus, epileptic brain function can be regulated by the enhanced trafficking of AMPAR due to Hebbian plasticity with increased simultaneous neuronal firing and compensational downregulation of cell-surface AMPARs by the synaptic scaling.
• Clinical impact of amyloid PET using 18F‑florbetapir in patients with cognitive impairment and suspected Alzheimer’s disease: a multicenter study

  Hiroshi Matsuda; Kyoji Okita; Yumiko Motoi; Toshiki Mizuno; Manabu Ikeda; Nobuo Sanjo; Koji Murakami; Taiki Kambe; Toshiki Takayam; · Kei Yamad; Takashi Suehiro; Keiko Matsunag; Takanori Yokota; Ukihide Tateishi; Yoko Shigemoto; Yukio Kimura; Emiko Chiba; Takahiro Kawashim; Yui Tomo; Hisateru Tachimori; Yuichi Kimura; Noriko Sato

  Annals of Nuclear Medicine Springer Science and Business Media LLC 36 (12) 1039 - 1049 0914-7187 2022/10 [Refereed]
   

  Abstract Objective Amyloid positron emission tomography (PET) can reliably detect senile plaques and fluorinated ligands are approved for clinical use. However, the clinical impact of amyloid PET imaging is still under investigation. The aim of this study was to evaluate the diagnostic impact and clinical utility in patient management of amyloid PET using ¹⁸F-florbetapir in patients with cognitive impairment and suspected Alzheimer’s disease (AD). We also aimed to determine the cutoffs for amyloid positivity for quantitative measures by investigating the agreement between quantitative and visual assessments. Methods Ninety-nine patients suspected of having AD underwent ¹⁸F-florbetapir PET at five institutions. Site-specialized physicians provided a diagnosis of AD or non-AD with a percentage estimate of their confidence and their plan for patient management in terms of medication, prescription dosage, additional diagnostic tests, and care planning both before and after receiving the amyloid imaging results. A PET image for each patient was visually assessed and dichotomously rated as either amyloid-positive or amyloid-negative by four board-certified nuclear medicine physicians. The PET images were also quantitatively analyzed using the standardized uptake value ratio (SUVR) and Centiloid (CL) scale. Results Visual interpretation obtained 48 positive and 51 negative PET scans. The amyloid PET results changed the AD and non-AD diagnosis in 39 of 99 patients (39.3%). The change rates of 26 of the 54 patients (48.1%) with a pre-scan AD diagnosis were significantly higher than those of 13 of the 45 patients with a pre-scan non-AD diagnosis (χ² = 5.334, p = 0.0209). Amyloid PET results also resulted in at least one change to the patient management plan in 42 patients (42%), mainly medication (20 patients, 20%) and care planning (25 patients, 25%). Receiver-operating characteristic analysis determined the best agreement of the quantitative assessments and visual interpretation of PET scans to have an area under the curve of 0.993 at an SUVR of 1.19 and CL of 25.9. Conclusion Amyloid PET using ¹⁸F-florbetapir PET had a substantial clinical impact on AD and non-AD diagnosis and on patient management by enhancing diagnostic confidence. In addition, the quantitative measures may improve the visual interpretation of amyloid positivity.
• Automatic detection of primary and metastatic lesions on cervicothoracic region and whole-body bone using a uniform machine-learnable approach for [18F]-FDG-PET/CT image analysis.

  Mitsutaka Nemoto; Atsuko Tanaka; Hayato Kaida; Yuichi Kimura; Takashi Nagaoka; Takahiro Yamada; Kohei Hanaoka; Kazuhiro Kitajima; Tatsuya Tsuchitani; Kazunari Ishii

  Physics in medicine and biology 67 (19) 2022/09 [Refereed]
   

  We propose a method to detect primary and metastatic lesions with Fluorine-18 fluorodeoxyglucose (FDG) accumulation in the lung field, neck, mediastinum, and bony regions on the FDG-PET/CT images. To search for systemic lesions, various anatomical structures must be considered. The proposed method is addressed by using an extraction process for anatomical regions and a uniform lesion detection approach. The uniform approach does not utilize processes that reflect any region-specific anatomical aspects but has a machine-learnable framework. Therefore, it can work as a lesion detection process for a specific anatomical region if it machine-learns the specific region data. In this study, three lesion detection processes for the whole-body bone region, lung field, or neck-mediastinum region are obtained. These detection processes include lesion candidate detection and false positive (FP) candidate elimination. The lesion candidate detection is based on a voxel anomaly detection with a one-class support vector machine. The FP candidate elimination is performed using an AdaBoost classifier ensemble. The image features used by the ensemble are selected sequentially during training and are optimal for candidate classification. Three-fold cross-validation was used to detect performance with the 54 diseased FDG-PET/CT images. The mean sensitivity for detecting primary and metastatic lesions at 3 FPs per case was 0.89 with a 0.10 standard deviation (SD) in the bone region, 0.80 with a 0.10 SD in the lung field, and 0.87 with a 0.10 SD in the neck region. The average areas under the ROC curve were 0.887 with a 0.125 SD for detecting bone metastases, 0.900 with a 0.063 SD for detecting pulmonary lesions, and 0.927 with a 0.035 SD for detecting the neck-mediastinum lesions. These detection performances indicate that the proposed method could be applied clinically. These results also show that the uniform approach has high versatility for providing various lesion detection processes.
• 教職課程履修学生のICT活用指導力の現状と課題 --- 「教育の情報化手引き」と「教員のICT活用指導力チェックリスト」に基づいて ---

  伊藤 大輔; 木村 竜也; 木村 裕一

  秋田県立大学ウェブジャーナル A 10 2022/09
• Robustness of a U-net model for different image processing types in segmentation of the mammary gland region

  Mika Yamamuro; Yoshiyuki Asai; Naomi Hashimoto; Nao Yasuda; Hiroto Kimura; Takahiro Yamada; Mitsutaka Nemoto; Yuichi Kimura; Hisashi Handa; Hisashi Yoshida; Koji Abe; Masahiro Tada; Hitoshi Habe; Takashi Nagaoka; Seiun Nin; Kazunari Ishii; Yongbum Lee

  16th International Workshop on Breast Imaging (IWBI2022) SPIE 2022/07
• Utility of U-Net for the objective segmentation of the fibroglandular tissue region on clinical digital mammograms.

  Mika Yamamuro; Yoshiyuki Asai; Naomi Hashimoto; Nao Yasuda; Hiroto Kimura; Takahiro Yamada; Mitsutaka Nemoto; Yuichi Kimura; Hisashi Handa; Hisashi Yoshida; Koji Abe; Masahiro Tada; Hitoshi Habe; Takashi Nagaoka; Seiun Nin; Kazunari Ishii; Yohan Kondo

  Biomedical physics & engineering express 8 (4) 2022/06 [Refereed]
   

  This study investigates the equivalence or compatibility between U-Net and visual segmentations of fibroglandular tissue regions by mammography experts for calculating the breast density and mean glandular dose (MGD). A total of 703 mediolateral oblique-view mammograms were used for segmentation. Two region types were set as the ground truth (determined visually): (1) one type included only the region where fibroglandular tissue was identifiable (called the 'dense region'); (2) the other type included the region where the fibroglandular tissue may have existed in the past, provided that apparent adipose-only parts, such as the retromammary space, are excluded (the 'diffuse region'). U-Net was trained to segment the fibroglandular tissue region with an adaptive moment estimation optimiser, five-fold cross-validated with 400 training and 100 validation mammograms, and tested with 203 mammograms. The breast density and MGD were calculated using the van Engeland and Dance formulas, respectively, and compared between U-Net and the ground truth with the Dice similarity coefficient and Bland-Altman analysis. Dice similarity coefficients between U-Net and the ground truth were 0.895 and 0.939 for the dense and diffuse regions, respectively. In the Bland-Altman analysis, no proportional or fixed errors were discovered in either the dense or diffuse region for breast density, whereas a slight proportional error was discovered in both regions for the MGD (the slopes of the regression lines were -0.0299 and -0.0443 for the dense and diffuse regions, respectively). Consequently, the U-Net and ground truth were deemed equivalent (interchangeable) for breast density and compatible (interchangeable following four simple arithmetic operations) for MGD. U-Net-based segmentation of the fibroglandular tissue region was satisfactory for both regions, providing reliable segmentation for breast density and MGD calculations. U-Net will be useful in developing a reliable individualised screening-mammography programme, instead of relying on the visual judgement of mammography experts.
• A Deep Learning System to Diagnose COVID-19 Pneumonia Using Masked Lung CT Images to Avoid AI-Generated COVID-19 Diagnoses that Include Data Outside the Lungs

  Takashi Nagaoka; Takenori Kozuka; Takahiro Yamada; Hitoshi Habe; Mitsutaka Nemoto; Masahiro Tada; Koji Abe; Hisashi Handa; Hisashi Yoshida; Kazunari Ishii; Yuichi Kimura

  Advanced Biomedical Engineering Japanese Society for Medical and Biological Engineering 11 76 - 86 2022 [Refereed]
  
• A Review on AI in PET Imaging

  Keisuke Matsubara; Masanobu Ibaraki; Mitsutaka Nemoto a; Hiroshi Watabe; Yuichi Kimura

  Annals of Nuclear Medicine 2021/12 [Refereed][Invited]
  
• Application of correlated component analysis to dynamic PET time-activity curves denoising.

  Paulus Kapundja Shigwedha; Takahiro Yamada; Kohei Hanaoka; Kazunari Ishii; Yuichi Kimura; Yutaka Fukuoka

  Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2021 3680 - 3683 2021/11 

  Positron emission tomography (PET) is a physiological, non-invasive imaging technique, which forms an essential part of nuclear medicine. The data obtained in a PET scan represent the concentration of an administered radiotracer in tissues over time. Quantitative analysis of PET data makes possible the assessments of in-vivo physiological processes. The Logan graphical analysis (LGA) is one of the methods that are used for quantitative analysis of PET data. LGA transforms PET data into a simple linear relationship. The slope of the LGA linear relationship is a physiological quantity denoting receptor availability. This quantity is termed distribution volume ratio (DVR). LGA-based estimates of the DVR are negatively affected by the noise in PET data -leading to the DVR being underestimated. A number of approaches proposed to address this issue have been observed to reduce the bias at the cost precision. An alternative regression method, least-squares cubic (LSC), was recently applied to estimate the DVR in order to reduce the bias. LSC was observed to reduce the bias in the LGA-based estimates. However, slight increases were also observed in the variance of the LSC-based estimates. This calls for methods to act against the variance in the LSC-based estimates. In this study, an alternative method is applied for tTAC denoising. This method is referred to as correlated component analysis (CorrCA). CorrCA transform the data by searching for dimensions of maximum correlation. This technique is closely related to other well-known methods such as principal component analysis and independent component analysis. In this study, the data were denoised by CorrCA (to act against the variance in the estimate) and the DVR was estimated by LSC, which provides for minimal bias. The resulting method LSC-CorrCA, gave less-biased estimated with increased precision. This was observed for both simulation results as well as for clinical data, both for 11C Pittsburgh compound B. Simulation data revealed reduced variances in LCS-CorrCA-based estimates, and the clinical data showed improved contrast between gray and white matter regions.Clinical Relevance-Improved DVR estimates would ease the interpretation of medical images, which will in turn positively influence the clinical processes, from diagnosis to treatment and follow-ups.
• Generative image transformer (GIT): unsupervised continuous image generative and transformable model for [123I]FP-CIT SPECT images

  Shogo Watanabe; Tomohiro Ueno; Yuichi Kimura; Masahiro Mishina; Naozo Sugimoto

  Annals of Nuclear Medicine Springer Science and Business Media LLC 35 1203 - 1213 0914-7187 2021/08 [Refereed]
  
• Relationship between F-18 florbetapir uptake in occipital lobe and neurocognitive performance in Alzheimer’s disease

  Tanyaluck Thientunyakit; Thonnapong Thongpraparn; Chakmeedaj Sethanandha; Takahiro Yamada; Yuichi Kimura; Weerasak Muangpaisan; Kazunari Ishii

  Japanese Journal of Radiology Springer Science and Business Media LLC 39 (10) 984 - 993 1867-1071 2021/05 [Refereed]
   

  PURPOSE: To determine the association between occipital amyloid-PET uptake and neurocognitive performance in Alzheimer's disease (AD). MATERIALS AND METHODS: Fifty-eight participants with normal aged, mild cognitive impairment (MCI) due to AD and AD subjects who underwent F-18 florbetapir brain PET/CT scans were divided into four groups (A, normal; B, MCI; C, mild AD; and D, moderate/severe AD). Semiquantitative analyses of SUVR images were performed. The differences between groups and the correlations between florbetapir uptake and Thai Mental State Examination (TMSE) scores were determined. Significant differences were defined using a P < 0.001, uncorrected, or a P < 0.05, FWE for the voxel-based analyses with Statistical Parametric Mapping (SPM). RESULTS: There was a slightly higher florbetapir uptake in the precuneus, parietal, and occipital association cortices in Group B > A. The occipital florbetapir uptake in Groups C and D was significantly higher than in Group A, in addition to the precuneus, anterior cingulate, posterior cingulate, temporoparietal, and frontal cortices. There was a strong negative correlation between TMSE scores and florbetapir uptake in the occipital lobe. CONCLUSIONS: Occipital amyloid uptake is associated with clinically advanced AD, and is inversely correlated with neurocognitive performance and may be useful for evaluating AD severity.
• Improving contrast between gray and white matter of Logan graphical analysis’ parametric images in positron emission tomography through least-squares cubic regression and principal component analysis

  Paulus Kapundja Shigwedha; Takahiro Yamada; Kohei Hanaoka; Kazunari Ishii; Yuichi Kimura; Yutaka Fukuoka

  Biomedical Physics & Engineering Express IOP Publishing 7 (3) 035003 - 035003 2021/05 [Refereed]
   

  Logan graphical analysis (LGA) is a method for in vivo quantification of tracer kinetics in positron emission tomography (PET). The shortcoming of LGA is the presence of a negative bias in the estimated parameters for noisy data. Various approaches have been proposed to address this issue. We recently applied an alternative regression method called least-squares cubic (LSC), which considers the errors in both the predictor and response variables to estimate the LGA slope. LSC reduced the bias in non-displaceable binding potential estimates while causing slight increases in the variance. In this study, we combined LSC with a principal component analysis (PCA) denoising technique to counteract the effects of variance on parametric image quality, which was assessed in terms of the contrast between gray and white matter. Tissue time-activity curves were denoised through PCA, prior to estimating the regression parameters using LSC. We refer to this approach as LSC-PCA. LSC-PCA was assessed against OLS-PCA (PCA with ordinary least-squares (OLS)), LSC, and conventional OLS-based LGA. Comparisons were made for simulated11C-carfentanil and11C Pittsburgh compound B (11C-PiB) data, and clinical11C-PiB PET images. PCA-based methods were compared over a range of principal components, varied by the percentage variance they account for in the data. The results showed reduced variances in distribution volume ratio estimates in the simulations for LSC-PCA compared to LSC, and lower bias compared to OLS-PCA and OLS. Contrasts were not significantly improved in clinical data, but they showed a significant improvement in simulation data |indicating a potential advantage of LSC-PCA over OLS-PCA. The effects of bias reintroduction when many principal components are used were also observed in OLS-PCA clinical images. We therefore encourage the use of LSC-PCA. LSC-PCA can allow the use of many principal components with minimal risk of bias, thereby strengthening the interpretation of PET parametric images.
• How to select training data to segment mammary gland region using a deep-learning approach for reliable individualized screening mammography

  Mika Yamamuro; Yoshiyuki Asai; Naomi Hashimoto; Nao Yasuda; Takahiro Yamada; Mitsutaka Nemoto; Yuichi Kimura; Hisashi Handa; Hisashi Yoshida; Koji Abe; Masahiro Tada; Hitoshi Habe; Takashi Nagaoka; Yoshiaki Ozaki; Seiun Nin; Kazunari Ishii; Yongbum Lee

  Medical Imaging 2021: Computer-Aided Diagnosis SPIE 2021/02
• Activities around the JSMBE Guideline under Clinical Trials Act of Japan

  Kuroda Tomohiro; Sakurai Risa; Kimura Yuichi

  Transactions of Japanese Society for Medical and Biological Engineering Japanese Society for Medical and Biological Engineering Annual59 (Abstract) 201 - 201 1347-443X 2021 

  The Clinical Research Act enforced in April 2018 states that only those with a doctor's license can carry out clinical research. Therefore, to clarify whether a research is categorized as clinical research or not is quite important issue for biomedical engineering researchers. In October 2019, JSMBE issued guideline to Classify Biomedical Engineering Research under the act. In this guideline, the two conditions of 1) not including prevention / diagnosis / treatment and 2) not affecting the structure or function of the body are used as criteria. Since detailed judgment criteria of condition 2 may differ, it is required to create an attached table to show the criterion for each individual field. In this panel discussion, we will discuss how the activities can affect the ongoing amendment of the act with an MHLW personnel.
• 在宅医療と人工臓器の過去・現在・未来 在宅医療を取り巻く個人情報保護法制の実際

  黒田 知宏; 黒田 佑輝; 櫻井 理紗; 木村 裕一

  人工臓器 (一社)日本人工臓器学会 49 (2) S - 25 0300-0818 2020/10
• Principal to Decide the Applicability of BME Researches to Clinical Trial Act of Japan

  Risa Sakurai; Tomohiro Kuroda; Masaru Sugimachi; Hideo Nakamura; Yuichi Kimura

  Transactions of Japanese Society for Medical and Biological Engineering 58 (4-5) 134 - 146 1881-4379 2020/10 [Refereed][Invited]
   

  The Clinical Trials Act introduced in Japan in April 2018 requires measures to ensure the safety of subjects. As defined in the act, the term “clinical trials” refers to such research that is conducted to clarify an efficacy or safety of medicines, medical devices, and medical instrument by testing them in people, that is, by using them in a medical practice. If a research is recognized as a clinical trial, the act requests judicious procedure to conduct the research. However, the definition of medical practice has not been interpreted systematically. Therefore, medical-engineering researchers have difficulty in deciding whether their study involves a medical practice. As a result, the act may cause reduction of researches in biomedical engineering. Here, we try to clarify the principles used to decide whether a research is classified as a “clinical trial” and to provide a summary for medical-engineering researchers as a guideline of the Japanese Society for Medical and Biomedical Engineering. We apply the guideline to several examples to show its efficiency.
• 【臨床研究法と該当性判断のためのガイドライン特集論文】生体医工学研究における臨床研究法への該当性判断の原理

  櫻井 理紗; 黒田 知宏; 杉町 勝; 中村 英夫; 木村 裕一

  生体医工学 (公社)日本生体医工学会 58 (4-5) 134 - 145 1347-443X 2020/09
• One-class SVMによる画素悪性度の集中性を用いたFDG-PET/CT上の病変自動検出

  田中 敦子; 根本 充貴; 甲斐田 勇人; 木村 裕一; 永岡 隆; 牛房 和之; 山田 誉大; 花岡 宏平; 北島 一宏; 槌谷 達也; 石井 一成

  日本医用画像工学会大会予稿集 日本医用画像工学会 39回 29 - 29 2020/09
• One-class SVMによる画素悪性度の集中性を用いたFDG-PET/CT上の病変自動検出

  田中 敦子; 根本 充貴; 甲斐田 勇人; 木村 裕一; 永岡 隆; 牛房 和之; 山田 誉大; 花岡 宏平; 北島 一宏; 槌谷 達也; 石井 一成

  日本医用画像工学会大会予稿集 日本医用画像工学会 39回 153 - 158 2020/09
• Regional Gray-Matter-Dedicated SUVR with 3D-MRI Detects Positive Amyloid Deposits in Equivocal Amyloid PET Images

  Kazunari Ishii; Takahiro Yamada; Kohei Hanaoka; Hayato Kaida; Koichi Miyazaki; Masami Ueda; Kazushi Hanada; Kazumasa Saigoh; Julia Sauerbeck; Axel Rominger; Peter Bartenstein; Yuichi Kimura

  Annals of Nuclear Medicine 34 (10) 0 - 0 2020/09 [Refereed]
   

  in press. Accepted on July 27, 2020.
• AI approach of cycle-consistent generative adversarial networks to synthesize PET images to train computer-aided diagnosis algorithm for dementia.

  Yuichi Kimura; Aya Watanabe; Takahiro Yamada; Shogo Watanabe; Takashi Nagaoka; Mitsutaka Nemoto; Koichi Miyazaki; Kohei Hanaoka; Hayato Kaida; Kazunari Ishii

  Annals of nuclear medicine 34 (7) 512 - 515 2020/07 [Refereed]
   

  OBJECTIVE: An artificial intelligence (AI)-based algorithm typically requires a considerable amount of training data; however, few training images are available for dementia with Lewy bodies and frontotemporal lobar degeneration. Therefore, this study aims to present the potential of cycle-consistent generative adversarial networks (CycleGAN) to obtain enough number of training images for AI-based computer-aided diagnosis (CAD) algorithms for diagnosing dementia. METHODS: We trained CycleGAN using 43 amyloid-negative and 45 positive images in slice-by-slice. RESULTS: The CycleGAN can be used to synthesize reasonable amyloid-positive images, and the continuity of slices was preserved. DISCUSSION: Our results show that CycleGAN has the potential to generate a sufficient number of training images for CAD of dementia.
• Automatic Diagnosis of melanoma using Hyperspectral data and GoogLeNet

  Ginji Hirano; Mitsutaka Nemoto; Yuichi Kimura; Yoshio Kiyohara; Hiroshi Koga; Naoya Yamazaki; Gustav Christensen; Christian Ingvar; Kari Nielsen; Atsushi Nakamura; Takayuki Sota; Takashi Nagaoka

  Skin Research and Technology 26 (6) 891 - 897 2020/06 [Refereed]
   

  Published online 2020/6/25.
• A strategy to account for noise in the X-variable to reduce underestimation in Logan graphical analysis for quantifying receptor density in positron emission tomography.

  Paulus K Shigwedha; Takahiro Yamada; Kohei Hanaoka; Kazunari Ishii; Yuichi Kimura; Yutaka Fukuoka

  BMC medical imaging 20 (1) 15 - 15 2020/02 [Refereed]
   

  BACKGROUND: The Logan graphical analysis (LGA) algorithm is widely used to quantify receptor density for parametric imaging in positron emission tomography (PET). Estimating receptor density, in terms of the non-displaceable binding potential (BPND), from the LGA using the ordinary least-squares (OLS) method has been found to be negatively biased owing to noise in PET data. This is because OLS does not consider errors in the X-variable (predictor variable). Existing bias reduction methods can either only reduce the bias slightly or reduce the bias accompanied by increased variation in the estimates. In this study, we addressed the bias reduction problem by applying a different regression method. METHODS: We employed least-squares cubic (LSC) linear regression, which accounts for errors in both variables as well as the correlation of these errors. Noise-free PET data were simulated, for 11C-carfentanil kinetics, with known BPND values. Statistical noise was added to these data and the BPNDs were re-estimated from the noisy data by three methods, conventional LGA, multilinear reference tissue model 2 (MRTM2), and LSC-based LGA; the results were compared. The three methods were also compared in terms of beta amyloid (A β) quantification of 11C-Pittsburgh compound B brain PET data for two patients with Alzheimer's disease and differing A β depositions. RESULTS: Amongst the three methods, for both synthetic and actual data, LSC was the least biased, followed by MRTM2, and then the conventional LGA, which was the most biased. Variations in the LSC estimates were smaller than those in the MRTM2 estimates. LSC also required a shorter computational time than MRTM2. CONCLUSIONS: The results suggest that LSC provides a better trade-off between the bias and variability than the other two methods. In particular, LSC performed better than MRTM2 in all aspects; bias, variability, and computational time. This makes LSC a promising method for BPND parametric imaging in PET studies.
• Automatic delineation algorithm of reference region for amyloid imaging based on kinetics.

  Takahiro Yamada; Shogo Watanabe; Takashi Nagaoka; Mitsutaka Nemoto; Kohei Hanaoka; Hayato Kaida; Kazunari Ishii; Yuichi Kimura

  Annals of nuclear medicine 34 (2) 102 - 107 2020/02 [Refereed]
   

  OBJECTIVE: This study aims to develop an algorithm named AutoRef to delineate a reference region for quantitative PET amyloid imaging. METHODS: AutoRef sets the reference region automatically using a distinguishing feature in the kinetics of reference region. This is reflected in the shapes of the tissue time activity curve. A statistical shape recognition algorithm of the gaussian mixture model is applied with considering spatial and temporal information on a reference region. We evaluate the BPND with manually set reference region and AutoRef using 86 cases (43 positive cases, 10 equivocal cases, and 33 negative cases) of dynamically scanned 11C-Pittsburgh Compound-B. RESULTS: From the Bland-Altman plot, the difference between two BPND is 0.099 ± 0.21 as standard deviation, and no significant systematic error is observed between the BPND with AutoRef and with manual definition of a reference region. Although a proportional error is detected, it is smaller than the 95% limits of agreement. Therefore, the proportional error is negligibly small. CONCLUSIONS: AutoRef presents the same performance as the manual definition of the reference region. Further, since AutoRef is more algorithmic than the ordinary manual definition of the reference region, there are few operator-oriented uncertainties in AutoRef. We thus conclude that AutoRef can be applied as an automatic delineating algorithm for the reference region in amyloid imaging.
• Visualization of AMPA receptors in living human brain with positron emission tomography.

  Tomoyuki Miyazaki; Waki Nakajima; Mai Hatano; Yusuke Shibata; Yoko Kuroki; Tetsu Arisawa; Asami Serizawa; Akane Sano; Sayaka Kogami; Tomomi Yamanoue; Kimito Kimura; Yushi Hirata; Yuuki Takada; Yoshinobu Ishiwata; Masaki Sonoda; Masaki Tokunaga; Chie Seki; Yuji Nagai; Takafumi Minamimoto; Kazunori Kawamura; Ming-Rong Zhang; Naoki Ikegaya; Masaki Iwasaki; Naoto Kunii; Yuichi Kimura; Fumio Yamashita; Masataka Taguri; Hideaki Tani; Nobuhiro Nagai; Teruki Koizumi; Shinichiro Nakajima; Masaru Mimura; Michisuke Yuzaki; Hiroki Kato; Makoto Higuchi; Hiroyuki Uchida; Takuya Takahashi

  Nature medicine 26 (2) 281 - 288 2020/02 [Refereed]
   

  Although aberrations in the number and function of glutamate AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors are thought to underlie neuropsychiatric disorders, no methods are currently available for visualizing AMPA receptors in the living human brain. Here we developed a positron emission tomography (PET) tracer for AMPA receptors. A derivative of 4-[2-(phenylsulfonylamino)ethylthio]-2,6-difluoro-phenoxyacetamide radiolabeled with 11C ([11C]K-2) showed specific binding to AMPA receptors. Our clinical trial with healthy human participants confirmed reversible binding of [11C]K-2 in the brain according to Logan graphical analysis (UMIN000020975; study design: non-randomized, single arm; primary outcome: dynamics and distribution volumes of [11C]K-2 in the brain; secondary outcome: adverse events of [11C]K-2 during the 4-10 d following dosing; this trial met prespecified endpoints). In an exploratory clinical study including patients with epilepsy, we detected increased [11C]K-2 uptake in the epileptogenic focus of patients with mesial temporal lobe epilepsy, which was closely correlated with the local AMPA receptor protein distribution in surgical specimens from the same individuals (UMIN000025090; study design: non-randomized, single arm; primary outcome: correlation between [11C]K-2 uptake measured with PET before surgery and AMPA receptor protein density examined by biochemical study after surgery; secondary outcome: adverse events during the 7 d following PET scan; this trial met prespecified endpoints). Thus, [11C]K-2 is a potent PET tracer for AMPA receptors, potentially providing a tool to examine the involvement of AMPA receptors in neuropsychiatric disorders.
• Automatic Diagnosis of melanoma using Hyperspectral data

  Hirano Ginji; Nemoto Mitsutaka; Kimura Yuichi; Nagaoka Takashi

  Transactions of Japanese Society for Medical and Biological Engineering Japanese Society for Medical and Biological Engineering Annual58 (Abstract) 275 - 275 1347-443X 2020 

  Melanoma is a type of superficial tumor and should be treated in an early stage. Early-stage melanoma is difficult to diagnose because it looks like a benign lesion. However, melanoma is still subjectively diagnosed by a dermatologist. Therefore, there is strong need for development of a quantitative diagnostic method. We are developing an automatic melanoma diagnostic system using convolutional neural network and hyperspectral imager. Hyperspectral imager acquires position and wavelength information simultaneously. 3D patches (16x16x201) extracted from hyperspectral data (560x680x210) is input to our newly proposed network. The total number of hyperspectral data was 202, including 88 melanomas and 114 non-melanomas. Our dataset was evaluated by 5-fold cross-validation and calculated sensitivity, specificity and accuracy. In this paper, the result of training and validation using patch data is reported.
• To Clarify Guideline to Classify Biomedical Engineering Research under Clinical Trials Act of Japan

  Kuroda Tomohiro; Sakurai Risa; Shunsuke Yoshimoto; Nakamura Hideo; Sugimachi Masaru; Yuichi Kimura

  Transactions of Japanese Society for Medical and Biological Engineering Japanese Society for Medical and Biological Engineering 58 217 - 217 1347-443X 2020 

  Japan has introduced Clinical Trials Act in April 2018 with unique definition of "clinical trials". Once defined as a clinical trial, the research has to be conducted by ones with medical doctor license. As a result, the act discourages medical and biomedical engineering researchers, mostly engineering-origin researchers without medical doctor license, to engage in research activities. In order to promote medical and biomedical engineering researches, Japanese Society for Medical and Biomedical Engineering issued guideline for researchers to check whether a particular research is classified as clinical trial under the clinical trial act definition on October 2019. Although the guideline provides general classification criteria, contributions of members to develop detailed criteria should be given for each research approach, such as electric-stimuli, motor-assistance, etc. is expected. Keywords: The Clinical Trials Act of Japan, Guideline, Classification Criteria.

• To Clarify Guideline to Classify Biomedical Engineering Research under Clinical Trials Act of Japan

  Kuroda Tomohiro; Sakurai Risa; Shunsuke Yoshimoto; Nakamura Hideo; Sugimachi Masaru; Yuichi Kimura

  Transactions of Japanese Society for Medical and Biological Engineering Japanese Society for Medical and Biological Engineering 58 550 - 552 1347-443X 2020 

  Japan has introduced Clinical Trials Act in April 2018 with unique definition of "clinical trials". Once defined as a clinical trial, the research has to be conducted by ones with medical doctor license. As a result, the act discourages medical and biomedical engineering researchers, mostly engineering-origin researchers without medical doctor license, to engage in research activities. In order to promote medical and biomedical engineering researches, Japanese Society for Medical and Biomedical Engineering issued guideline for researchers to check whether a particular research is classified as clinical trial under the clinical trial act definition on October 2019. Although the guideline provides general classification criteria, contributions of members to develop detailed criteria should be given for each research approach, such as electric-stimuli, motor-assistance, etc. is expected. Keywords: The Clinical Trials Act of Japan, Guideline, Classification Criteria.

• Performance Improvement of Automated Melanoma Diagnosis System by Data Augumentation

  Kana Kato; Mitsutaka Nemoto; Yuichi Kimura; Yoshio Kiyohara; Hiroshi Koga; Naoya Yamazaki; Gustav Christensen; Christian Ingvar; Kari Nielsen; Atsushi Nakamura; Takayuki Sota; Takashi Nagaoka

  Advanced Biomedical Engineering 9 62 - 70 2020/01 [Refereed]
  
• Dynamic PET Image Reconstruction Using Nonnegative Matrix Factorization Incorporated with Deep Image Prior

  Tatsuya Yokota; Kazuya Kawai; Muneyuki Sakata; Yuichi Kimura; Hidekata Hontani

  International Conference on Computer Vision IEEE 3126 - 3135 2019/10 [Refereed]
  
• Micro-Liter Order Automatic Blood Sampling System for Fully Quantitative Analysis of Small Animal PET

  Akinori Takenaka; Yoshitaka Inui; Yuichi Kimura; Chikara Miyake; Yoichi Fujiyama; Takashi Yamada; obuya Hashizume; Takashi Kato; Kengo Ito; Hiroshi Toyama

  Annals of Nuclear Medicine 33 (8) 586 - 593 2019/08 [Refereed]
  
• Pilot study to generate image features by deep autoencoder for computer-aided detection systems

  Mitsutaka Nemoto; Kazuyuki Ushifusa; Atsuko Tanaka; Takahiro Yamada; Yuichi Kimura; Naoto Hayashi

  INTERNATIONAL FORUM ON MEDICAL IMAGING IN ASIA 2019 SPIE-INT SOC OPTICAL ENGINEERING 11050 0277-786X 2019 

  We propose an automatic feature generation by deep convolutional autoencoder (deep CAE) without lesion data. The main idea of the proposed method is based on anomaly detection. Deep CAE is trained by only normal volume patches. Trained deep CAE calculates low-dimensional features and reproduction error from 2.5 dimensional (2.5D) volume patch. The proposed method was evaluated experimentally with 150 chest CT cases. By using both previous features and the deep CAE based features, an improved classification performance was obtained; AUC=0.989 and ANODE=0.339.
• FDG-PET/CTの統計的異常検知処理による転移を考慮した頸胸部病変の自動検出

  田中 敦子; 根本 充貴; 甲斐田 勇人; 木村 裕一; 永岡 隆; 山田 誉大; 花岡 宏平; 石井 一成

  生体医工学 公益社団法人 日本生体医工学会 57 (0) S249_2 - S249_2 1347-443X 2019 

  【目的】臨床的価値の高いFDG-PET/CT画像診断における医師の負担軽減及び診断精度向上のため、FDG-PET/CTの画像パターンに対する異常検知処理に基づく頸胸部病変の自動検出法を提案する。【手法】FDG-PETは、糖代謝亢進を反映し腫瘍部位では異常集積を呈する。そこで提案法では、CTの閾値処理及びモルフォロジ処理にて左右肺野を自動抽出し、肺野を基準に縦隔領域を自動抽出する。次に領域ごとの健常組織画素値に関する統計モデルを用いた異常検知による病変候補の検出を行う。異常検知に用いる統計モデルは健常画像の画素(HU, SUV)の2次元正規分布モデルとし、マハラノビス距離を異常度として計測する。左肺、右肺、縦隔で個別に算出した異常度の閾値処理にて病変候補を得る。得られた候補領域から微小体積のものを削除し、腫瘍が疑われる部位を検出する。図に病変検出例を示す。【結果】臨床撮像された食道癌、肺癌の10症例の全身PET/CTを用いて提案法の評価実験を行ったところ、検出感度94.7%(18/19病変)、過検出数14.0個/例の性能が得られ、提案法の有用性を確認した。【結論】今後の課題は、病変検出感度の改善や誤検出病変候補の削減処理の追加が挙げられる。

• Quantitative Cosmetic Evaluation of Long-Lasting Foundation Using Multispectral Imaging

  NAGAOKA Takashi; KIMURA Yuichi

  Skin Research Technology 25 (3) 318 - 324 2018/12 [Refereed]
  
• Simultaneous PET Image reconstruction and Feature Extraction Method Using Non-negative, Smooth, and Sparse Matrix Factorization

  K. Kawai; H. Hontani; T. Yokota; M. Sakata; Y. Kimura

  Proceedings of APSIPA-ASC 2018 IEEE 1334 - 1337 2018/11 [Refereed]
  
• Performance Evaluation of Noise Reduction Algorithm for PET Amyloid Imaging Using Clinical Images.

  Yamada Takahiro; Kimura Yuichi; Fujii kosuke; Watanabe Shogo; Nagaoka Takashi; Nemoto Mitsutaka; Hanaoka Kohei; Kaida Hayato; Ishii Kazunari

  Transactions of Japanese Society for Medical and Biological Engineering Japanese Society for Medical and Biological Engineering 56 (0) S294 - S294 1347-443X 2018 

  This study aims to develop a noise reduction algorithm for amyloid PET imaging. A visualization of a small amyloid-β (Aβ) deposit is required for early diagnosis of Alzheimer's disease (AD) pathology, and a noise in amyloid image should be reduced without any loss of spatial resolution. Conventional noise reduction algorithms use spatial averaging, but our proposed algorithm, CAKS, averages pixels that have similar kinetics of administered PET radiopharmaceutical. As a result of CAKS applying to actual clinical images, the noise is reduced and the image quality is improved. The contrast between gray and white matters is significantly improved (p<.05). We concluded that CAKS is applied to clinical amyloid PET imaging is useful for diagnosis of AD pathology.

• A Robust PET Image Reconstruction using Constrained Non-negative Matrix Factorization

  K. Kawai; J. Yamada; H. Hontani; T. Yokota; M. Sakata; Y. Kimura

  Proceedings of the Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA ASC) IEEE 1815 - 1818 2017/12 [Refereed]
  
• Age-Related Decrease in Male Extra-Striatal Adenosine A(1) Receptors Measured Using C-11-MPDX PET

  Masahiro Mishina; Yuichi Kimura; Muneyuki Sakata; Kenji Ishii; Keiichi Oda; Jun Toyohara; Kazumi Kimura; Kiichi Ishiwata

  FRONTIERS IN PHARMACOLOGY FRONTIERS MEDIA SA 8 (903) 1663-9812 2017/12 [Refereed]
   

  Adenosine A(1) receptors (A(1)Rs) are widely distributed throughout the entire human brain, while adenosine A(2A) receptors (A(2A)Rs) are present in dopamine-rich areas of the brain, such as the basal ganglia. A past study using autoradiography reported a reduced binding ability of A(1)R in the striatum of old rats. We developed positron emission tomography (PET) ligands for mapping the adenosine receptors and we successfully visualized the A(1)Rs using 8-dicyclopropylmethyl-1-C-11-methyl-3-propylxanthine (C-11-MPDX). We previously reported that the density of A(1)Rs decreased with age in the human striatum, although we could not observe an age-related change in A(2A)Rs. The aim of this study was to investigate the age-related change of the density of A(1)Rs in the thalamus and cerebral cortices of healthy participants using C-11-MPDX PET. We recruited eight young (22.0 +/- 1.7 years) and nine elderly healthy male volunteers (65.7 +/- 8.0 years). A dynamic series of decay-corrected PET scans was performed for 60 min starting with the injection of C-11-MPDX. We placed the circular regions of interest of 10 mm in diameter in C-11-MPDX PET images. The values for the binding potential (BPND) of C-11-MPDX in the thalamus, and frontal, temporal, occipital, and parietal cortices were calculated using a graphical analysis, wherein the reference region was the cerebellum. BPND of C-11-MPDX was significantly lower in elderly participants than young participants in the thalamus, and frontal, temporal, occipital, and parietal cortices. In the human brain, we could observe the age-related decrease in the distribution of A(1)Rs.
• Parametric PET Image Reconstruction via Regional Spatial Bases and Pharmacokinetic Time Activity Model

  Naoki Kawamura; Tatsuya Yokota; Hidekata Hontani; Muneyuki Sakata; Yuichi Kimura

  ENTROPY MDPI AG 19 (11) 629  1099-4300 2017/11 [Refereed]
   

  It is known that the process of reconstruction of a Positron Emission Tomography (PET) image from sinogram data is very sensitive to measurement noises; it is still an important research topic to reconstruct PET images with high signal-to-noise ratios. In this paper, we propose a new reconstruction method for a temporal series of PET images from a temporal series of sinogram data. In the proposed method, PET images are reconstructed by minimizing the Kullback-Leibler divergence between the observed sinogram data and sinogram data derived from a parametric model of PET images. The contributions of the proposition include the following: (1) regions of targets in images are explicitly expressed using a set of spatial bases in order to ignore the noises in the background; (2) a parametric time activity model of PET images is explicitly introduced as a constraint; and (3) an algorithm for solving the optimization problem is clearly described. To demonstrate the advantages of the proposed method, quantitative evaluations are performed using both synthetic and clinical data of human brains.
• Adenosine A(1) receptors measured with C-11-MPDX PET in early Parkinson's disease

  Masahiro Mishina; Kenji Ishii; Yuichi Kimura; Masahiko Suzuki; Shin Kitamura; Kenji Ishibashi; Muneyuki Sakata; Keiichi Oda; Shiro Kobayashi; Kazumi Kimura; Kiichi Ishiwata

  SYNAPSE WILEY 71 (8) 0887-4476 2017/08 [Refereed]
   

  Adenosine A(1) receptors (A(1)Rs) interact negatively with dopamine D-1 receptors (D(1)Rs) in neurons of the basal ganglia's direct pathway, while adenosine A(2A) receptors (A(2A)Rs) negatively interact with dopamine D-2 receptors (D(2)Rs) in indirect-pathway neurons. The aim of this study was to investigate the cerebral density of A(1)Rs in Parkinson's disease (PD) in its early stages, using PET scans with the radioligand 8-dicyclopropylmethyl-1-C-11-methyl-3-propylxanthine (C-11-MPDX). We studied 10 drug-naive patients with early PD. Each patient was also examined for dopamine transporters (DATs) and D(2)Rs by PET using C-11-2--carbomethoxy-3--(4-fluorophenyl)-tropane (C-11-CFT) and C-11-raclopride (C-11-RAC), respectively. Ten elderly, healthy volunteers were recruited as controls for C-11-MPDX PET scanning and eight elderly volunteers were recruited as controls for C-11-CFT and C-11-RAC PET scanning. The PET scans revealed a decrease in the uptake ratio index (URI) of C-11-CFT and an increase in the URI of C-11-RAC in patients. In the temporal lobe, the binding potential for C-11-MPDX was higher in the patient group than in healthy subjects, but not in the other regions examined, including the striatum. In patients, we observed motor-symptom asymmetry and a relationship between parkinsonism and the striatal density of DATs, but not A(1)R density. In the putamen of early PD, asymmetrical down-regulation of A(2A)Rs is likely a compensatory mechanism in response to a decrease in dopamine. However, our study suggests that A(1)Rs are unaltered in the putamen of early PD.
• 薬剤動態に基づいたアミロイドイメージングに対する雑音低減アルゴリズム

  木村 裕一; 藤井 康介; 山田 誉大; 細川 知紗; 坂田 宗之; 石井 一成; 村上 卓道

  核医学 (一社)日本核医学会 53 (Suppl.) S277 - S277 0022-7854 2016/10
• Validation of automated delineation algorithm of reference regions in PET amyloid imaging based on kinetics of administered amyloid probe

  Yamada Takahiro; Kimura Yuichi; Nagaoka Takashi; Okada Shima; Hosokawa Chisa; Ishii Kazunari

  Transactions of Japanese Society for Medical and Biological Engineering Japanese Society for Medical and Biological Engineering 54 (26) S45 - S45 2016 

  A deposit of amyloid β (Aβ) to the central nervous system causes Alzheimer's disease (AD). A periodical evaluation on Aβ, a year, can therefor detect the beginning of AD, and it realizes an effective medical treatment for AD. For quantitative measurement of Aβ deposit is available using PET, and it requires to delineate the cerebellum gray matter as a reference region, when no Aβ deposit occurs physiologically and it has complicated shape. This study aim at proposing automated delineation algorithm based on a kinetics of administered PET tracer for Aβ imaging. The validation using a clinical data presented no significant difference (p < 0.05) between the amount of Aβ deposit using an ordinary manual delineation and the automated method. We can conclude that the algorithm is clinically useful.

• Performance of C-11-Pittsburgh Compound B PET Binding Potential Images in the Detection of Amyloid Deposits on Equivocal Static Images

  Chisa Hosokawa; Kazunari Ishii; Yuichi Kimura; Tomoko Hyodo; Makoto Hosono; Kenta Sakaguchi; Kimio Usami; Kenji Shimamoto; Yuzuru Yamazoe; Takamichi Murakami

  JOURNAL OF NUCLEAR MEDICINE SOC NUCLEAR MEDICINE INC 56 (12) 1910 - 1915 0161-5505 2015/12 [Refereed]
   

  The goal of this study was to clarify whether binding potential (BP) images using C-11-Pittsburgh compound B (C-11-PiB) and dynamic PET can reliably detect cortical amyloid deposits for patients whose C-11-PiB PET static images are ambiguous and whether visual ratings are affected by white matter retention. Methods: Static and BP images were constructed for 85 consecutive patients with cognitive impairment after C-11-PiB dynamic PET. Cortical uptake was visually assessed as positive, negative, or equivocal for both types of images. Quantitatively, the standardized uptake value ratio (SUVR) from the static image, the nondisplaceable BP from the dynamic image for mean gray matter uptake, and the ratio of gray matter uptake to white matter retention were compared among C-11-PiB-positive, C-11-PiB-equivocal, and C-11-PiB-negative groups. Results: Forty-three scans were visually assessed as C-11-PiB-positive in both the static and the BP images. Ten scans were C-11-PiB-equivocal in the static images. In 8 of them, the BP images were C-11-PiB-positive, whereas the other 2 were C-11-PiB-equivocal. Thirty-two scans were assessed as C-11-PiB-negative in the static images. In the BP images, 4 were C-11-PiB-positive and 2 were C-11-PiB-equivocal. The mean gray matter uptake of C-11-PiB in SUVR and nondisplaceable BP, respectively, showed statistically significant differences among the C-11-PiB-positive, C-11-PiB-equivocal, and C-11-PiB-negative groups. The ratio of gray matter uptake to white matter retention was lower in the BP images than static images from the C-11-PiB-negative and C-11-PiB-equivocal groups, whereas it was higher in the C-11-PiB-positive group. Conclusion: C-11-PiB PET BP images can clarify visual interpretation of clinical static C-11-PiB-equivocal images by reducing the interference of nonspecific white matter retention. We conclude that C-11-PiB-equivocal PET findings on static images reflect cortical amyloid deposits, which can be verified using BP images. Furthermore, quantitative assessments, such as SUVR and nondisplaceable BP, are of no use for correctly rating equivocal visual findings.
• PiB陰性例の18F-FDG PETによる脳代謝分布の検討

  細川 知紗; 石井 一成; 若林 雄一; 兵頭 朋子; 花田 一志; 甲斐田 勇人; 細野 眞; 木村 裕一; 村上 卓道

  核医学 (一社)日本核医学会 52 (3) 262 - 262 0022-7854 2015/09
• アミロイドイメージングにおける組織放射能時間曲線に対するパターン認識による参照領域設定アルゴリズム

  木村 裕一; 山田 誉大; 細川 知紗; 石井 一成; 村上 卓道

  核医学 (一社)日本核医学会 52 (3) 293 - 293 0022-7854 2015/09
• Change of image quality by kinds of basis functions in PET dynamic image of four-dimensional reconstruction

  YAMADA JUNNYA; HONTANI HIDEKAKTA; KIMURA YUICHI; SAKATA MUNEYUKI

  Transactions of Japanese Society for Medical and Biological Engineering Japanese Society for Medical and Biological Engineering 53 S214_02 - S214_02 2015 

  The authors studied the quality of dynamic PET images reconstructed from not a sinogram measured at each time but a set of sinograms measured during the observation. Representing a time activity curve observed at each voxel using set of basis functions, the authors reconstructed the images by estimating the coefficients for linear sum of the basis functions that maximize the likelihood. The likelihood is defined under the assumption that the measurement obey the Poisson distribution and maximized by means of an EM algorithm. In this presentation, the authors report that you can improve the image quality by simulnaneously reconstructing dynamic PET images from a set of all sinogram data.
• How to Submit Your Works — Ethical Issues and Conflict of Interest

  SUGIMACHI MASARU; KIMURA YUICHI

  Transactions of Japanese Society for Medical and Biological Engineering Japanese Society for Medical and Biological Engineering 53 S95_02 - S95_02 2015 

  原稿を投稿して論文を出版することは，世界中に研究成果を発信する最も強力な方法のひとつである．その一方で，著者は投稿に際しガイドラインやルールに緻密に従う必要がある．これらのルールは，投稿原稿が科学的なものでなければならないことから生じる満たすべき構成条件，すなわち新規性・重要性・信頼性と密接に関係している．本講演では引用，著作権，多重投稿，研究・出版倫理，動物やヒトを用いた研究についての倫理，利益相反開示などについて情報を提供し，会員の皆様の投稿や査読応答の際に役立てていただくことを目的とする．
• How to Submit Your Works — Writing and Reading

  Kimura Yuichi; Sugimachi Masaru

  Transactions of Japanese Society for Medical and Biological Engineering Japanese Society for Medical and Biological Engineering 53 S95_01 - S95_01 2015 

  読み易い論文は査読委員にとっても見易い論文であり、採録にも繋がる。そこで本講演では、実例を引きつつ、論文の書き方に纏わる作法について説明する。また、査読への対応、英語論文の読み方についても言及する。
• Clinical practice guideline for dedicated breast PET

  Makoto Hosono; Tsuneo Saga; Kengo Ito; Shinichiro Kumita; Masayuki Sasaki; Michio Senda; Jun Hatazawa; Hiroshi Watanabe; Hiroshi Ito; Shinichi Kanaya; Yuichi Kimura; Hideo Saji; Seishi Jinnouchi; Hiroyoshi Fukukita; Koji Murakami; Seigo Kinuya; Junichi Yamazaki; Mayuki Uchiyama; Koichi Uno; Katsuhiko Kato; Tsuyoshi Kawano; Kazuo Kubota; Takashi Togawa; Norinari Honda; Hirotaka Maruno; Mana Yoshimura; Masami Kawamoto; Yukihiko Ozawa

  ANNALS OF NUCLEAR MEDICINE SPRINGER 28 (6) 597 - 602 0914-7187 2014/07 [Refereed]
  
• Comparison between SUV and BP images acquired using 11C-PIB PET: Questionable PIB accumulation in SUV images

  Chisa Hosokawa; Kazunari Ishii; Yuichi Kimura; Kenta Sakaguchi; Makoto Hosono; Takamichi Murakami

  JOURNAL OF NUCLEAR MEDICINE SOC NUCLEAR MEDICINE INC 55 0161-5505 2014/05 [Refereed]
  
• Full quantification of CMRGlc of small animals with arterial blood sampling using the new system of CD-Well

  Kimura Yuichi; Yamada Takashi; Hashizume Nobuya; Nomura Masahiko; Ota Seiichiro; Kitamura Keishi; Toyama Hiroshi

  JOURNAL OF NUCLEAR MEDICINE 55 (22) 7889 - 7903 0161-5505 2014/05 [Refereed]
  
• Assessment of participant compliance with a Web-based home healthcare system for promoting specific health checkups

  Toshiyo Tamura; Sohichi Maeno; Takumu Hattori; Yutaka Kimura; Yuichi Kimura; Masaki Yoshida; Kotaro Minato

  BIOCYBERNETICS AND BIOMEDICAL ENGINEERING PWN-POLISH SCIENTIFIC PUBL 34 (1) 63 - 69 0208-5216 2014 [Refereed]
   

  We investigated the effectiveness of a Web-based healthcare system that allows participants to record measurements of blood pressure, body weight, and the number of steps walked per day. After receiving a medical examination, participants were registered on the Web-based system and encouraged to record data. A total of 223 participants initiated contact with the system; however, only 27 monitored their blood pressure on more than 60 days during the 3-month period. Furthermore, only 46 participants monitored their body weight, and 79 monitored the number of steps taken per day. Although specific health checkups are important to prevent diseases, we conclude that existing health checkup monitoring is not sufficient, and we should develop a new Web-based health checkup and monitoring system that is more familiar to the participants. (C) 2013 Nalecz Institute of Biocybernetics and Biomedical Engineering. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.
• Validation of a First Block-Iterative Spatio-Temporal Reconstruction Algorithm with Small Animal Dynamic PET Data

  Tatsuya Kon; Takashi Obi; Muneyuki Sakata; Nagaaki Ohyama; Yuichi Kimura

  Adv Biomed Eng Japanese Society for Medical and Biological Engineering 3 7 - 13 2187-5219 2014 [Refereed]
   

  Spatio-temporal reconstruction methods for positron emission tomography estimate the tissue time-activity curves that are required for functional imaging. Since the time-related change of activity at a voxel has a temporal correlation by itself, temporal basis function approaches can be adopted. However, these image reconstruction methods suffer from a high computational cost. We have proposed a novel spatio-temporal reconstruction method using a temporal basis function approach, which is based on a fast block-iterative algorithm named Dynamic Row-Action Maximum-Likelihood Algorithm (DRAMA). Using the proposed method, data quickly converge to an estimate after around two iterations. This study aimed to validate the performance of the proposed algorithm on small animal PET data. We applied the proposed method to ¹⁸F-FDG mouse dynamic PET data. A parametric image of regional glucose metabolism reconstructed from the proposed method was almost identical to those obtained from conventional reconstruction algorithms. The proposed method took 14.3 h for computation, which was twice as fast as conventional algorithms. These results support the usability of the proposed algorithm for voxel-by-voxel estimation.
• A gait abnormality measure based on root mean square of trunk acceleration

  Masaki Sekine; Toshiyo Tamura; Masaki Yoshida; Yuki Suda; Yuichi Kimura; Hiroaki Miyoshi; Yoshifumi Kijima; Yuji Higashi; Toshiro Fujimoto

  JOURNAL OF NEUROENGINEERING AND REHABILITATION BIOMED CENTRAL LTD 10 118  1743-0003 2013/12 [Refereed]
   

  Background: Root mean square (RMS) of trunk acceleration is seen frequently in gait analysis research. However, many studies have reported that the RMS value was related to walking speed. Therefore, the relationship between the RMS value and walking speed should be considered when the RMS value is used to assess gait abnormality. We hypothesized that the RMS values in three sensing axes exhibit common proportions for healthy people if they walk at their own preferred speed and that the RMS proportions in abnormal gait deviate from the common proportions. In this study, we proposed the RMS ratio (RMSR) as a gait abnormality measure and verified its ability to discriminate abnormal gait. Methods: Forty-seven healthy male subjects (24-49 years) were recruited to examine the relationship between walking speed and the RMSR. To verify its ability to discriminate abnormal gait, twenty age-matched male hemiplegic patients (30-48 years) participated as typical subjects with gait abnormality. A tri-axial accelerometer was attached to their lower back, and they walked along a corridor at their own preferred speed. We defined the RMSR as the ratio between RMS in each direction and the RMS vector magnitude. Results: In the healthy subjects, the RMS in all directions related to preferred walking speed. In contrast, RMSR in the mediolateral (ML) direction did not correlate with preferred walking speed (rs = -0.10, p = 0.54) and represented the similar value among the healthy subjects. Moreover, the RMSR in the ML direction for the hemiplegic patients was significantly higher than that for the healthy subjects (p < 0.01). Conclusions: These results suggest that the RMSR in the ML direction exhibits a common value when healthy subjects walk at their own preferred speed, even if their preferred walking speed were different. For subjects with gait abnormality, the RMSR in the ML direction deviates from the common value of healthy subjects. The RMSR in the ML direction may potentially be a quantitative measure of gait abnormality.
• A gait abnormality measure based on root mean square of trunk acceleration

  Masaki Sekine; Toshiyo Tamura; Masaki Yoshida; Yuki Suda; Yuichi Kimura; Hiroaki Miyoshi; Yoshifumi Kijima; Yuji Higashi; Toshiro Fujimoto

  JOURNAL OF NEUROENGINEERING AND REHABILITATION BIOMED CENTRAL LTD 10 (118) 1 - 7 1743-0003 2013/12 [Refereed]
   

  Background: Root mean square (RMS) of trunk acceleration is seen frequently in gait analysis research. However, many studies have reported that the RMS value was related to walking speed. Therefore, the relationship between the RMS value and walking speed should be considered when the RMS value is used to assess gait abnormality. We hypothesized that the RMS values in three sensing axes exhibit common proportions for healthy people if they walk at their own preferred speed and that the RMS proportions in abnormal gait deviate from the common proportions. In this study, we proposed the RMS ratio (RMSR) as a gait abnormality measure and verified its ability to discriminate abnormal gait. Methods: Forty-seven healthy male subjects (24-49 years) were recruited to examine the relationship between walking speed and the RMSR. To verify its ability to discriminate abnormal gait, twenty age-matched male hemiplegic patients (30-48 years) participated as typical subjects with gait abnormality. A tri-axial accelerometer was attached to their lower back, and they walked along a corridor at their own preferred speed. We defined the RMSR as the ratio between RMS in each direction and the RMS vector magnitude. Results: In the healthy subjects, the RMS in all directions related to preferred walking speed. In contrast, RMSR in the mediolateral (ML) direction did not correlate with preferred walking speed (rs = -0.10, p = 0.54) and represented the similar value among the healthy subjects. Moreover, the RMSR in the ML direction for the hemiplegic patients was significantly higher than that for the healthy subjects (p < 0.01). Conclusions: These results suggest that the RMSR in the ML direction exhibits a common value when healthy subjects walk at their own preferred speed, even if their preferred walking speed were different. For subjects with gait abnormality, the RMSR in the ML direction deviates from the common value of healthy subjects. The RMSR in the ML direction may potentially be a quantitative measure of gait abnormality.
• 11C-PIB-PETの視覚判定と定量評価 疑い判定の検討

  細川 知紗; 石井 一成; 木村 裕一; 兵頭 朋子; 坂口 健太; 宇佐美 公男; 細野 眞; 村上 卓道

  核医学 (一社)日本核医学会 50 (4) 327 - 327 0022-7854 2013/11
• Novel system using microliter order sample volume for measuring arterial radioactivity concentrations in whole blood and plasma for mouse PET dynamic study

  Yuichi Kimura; Chie Seki; Nobuya Hashizume; Takashi Yamada; Hidekatsu Wakizaka; Takahiro Nishimoto; Kentaro Hatano; Keishi Kitamura; Hiroshi Toyama; Iwao Kanno

  PHYSICS IN MEDICINE AND BIOLOGY IOP PUBLISHING LTD 58 (22) 7889 - 7903 0031-9155 2013/11 [Refereed]
   

  This study aimed to develop a new system, named CD-Well, for mouse PET dynamic study. CD-Well allows the determination of time-activity curves (TACs) for arterial whole blood and plasma using 2-3 mu L of blood per sample; the minute sample size is ideal for studies in small animals. The system has the following merits: (1) measures volume and radioactivity of whole blood and plasma separately; (2) allows measurements at 10 s intervals to capture initial rapid changes in the TAC; and (3) is compact and easy to handle, minimizes blood loss from sampling, and delay and dispersion of the TAC. CD-Well has 36 U-shaped channels. A drop of blood is sampled into the opening of the channel and stored there. After serial sampling is completed, CD-Well is centrifuged and scanned using a flatbed scanner to define the regions of plasma and blood cells. The length measured is converted to volume because the channels have a precise and uniform cross section. Then, CD-Well is exposed to an imaging plate to measure radioactivity. Finally, radioactivity concentrations are computed. We evaluated the performance of CD-Well in in vitro measurement and in vivo F-18-fluorodeoxyglucose and [C-11] 2-carbomethoxy-3 beta-(4-fluorophenyl) tropane studies. In in vitro evaluation, per cent differences (mean +/- SE) from manual measurement were 4.4 +/- 3.6% for whole blood and 4.0 +/- 3.5% for plasma across the typical range of radioactivity measured in mouse dynamic study. In in vivo studies, reasonable TACs were obtained. The peaks were captured well, and the time courses coincided well with the TAC derived from PET imaging of the heart chamber. The total blood loss was less than 200 mu L, which had no physiological effect on the mice. CD-Well demonstrates satisfactory performance, and is useful for mouse PET dynamic study.
• 乳房専用PET診療ガイドライン 平成25年7月

  細野 眞; 佐賀 恒夫; 伊藤 健吾; 汲田 伸一郎; 佐々木 雅之; 千田 道雄; 畑澤 順; 渡邉 浩; 伊藤 浩; 金谷 信一; 木村 裕一; 佐治 英郎; 陣之内 正史; 福喜多 博義; 村上 康二; 絹谷 清剛; 山崎 純一; 内山 眞幸; 宇野 公一; 加藤 克彦; 川野 剛; 窪田 和雄; 戸川 貴史; 本田 憲業; 丸野 廣大; 吉村 真奈; 川本 雅美; 小澤 幸彦; 日本核医学会PET核医学委員会, 日本核医学会健保委員会

  核医学 (一社)日本核医学会 50 (3) 1 - 9 0022-7854 2013/09
• 11C-PIB PETのSUVR画像とBP画像の対比

  細川 知紗; 石井 一成; 木村 裕一; 兵頭 朋子; 細野 眞; 坂口 健太; 宇佐美 公男; 村上 卓道

  核医学 (一社)日本核医学会 50 (3) S182 - S182 0022-7854 2013/09
• A wearable motion sensor for evaluating walking performance in Parkinson’s disease with treatments

  Toshiyo Tamura; Yuki Suda; Masaki Sekine; Yuichi Kimura; Tomoyuki Uchiyama

  Biosystems and Biorobotics Springer International Publishing 1 717 - 720 2195-3570 2013 [Refereed]
   

  A new treatment, deep brain stimulation (DBS), is available for the management Parkinson’s disease. However, the assessment of its efficacy is limited by the inadequacies of current methods. The present study was performed to develop and validate a portable device capable of objectively measuring the performance and therapeutic efficiency of Parkinson’s disease by walking performance. The developed wearable motion sensor with accelerometer and gyro sensor was used to measure walking performance under DBS-off, DBS-on, and medication conditions. The root mean square (RMS) and coefficient of variations (CV) of acceleration signals were compared between controls and patients with medication. The results indicated significantly improved walking balance after medication. DBS-on improved performance but the effect was not statistically significant.
• Human Brain Imaging of Adenosine Receptors

  Masahiro Mishina; Yuichi Kimura; Kiich Ishiwata

  Imaging of the Human Brain in Health and Disease Elsevier Inc. 161 - 186 2013 [Refereed]
   

  Adenosine is an endogenous modulator of various physiological functions mediated by adenosine receptors (ARs). Advances in radiotracer chemistry have led to the development of novel imaging probes for ARs, especially adenosine A< inf> 1< /inf> and A< inf> 2A< /inf> receptors. In this review, we discuss (1) functions of adenosine and ARs in the central nervous system (2) brain imaging for ARs, including postmortem studies and positron emission tomography (3) comparison of radioligands for AR imaging in health and diseases and (4) kinetic analysis for quantitative AR imaging. © 2014 Elsevier Inc. All rights reserved.
• Application of a pedometer in a clinical setting: is the number of walking steps predictive of changes in blood pressure?

  Toshiyo Tammura; Soichi Maeno; Yutaka Kimira; Takumu Hattori; Yuichi Kimura; Kotaro Minato

  2013 IEEE INTERNATIONAL CONFERENCE ON BODY SENSOR NETWORKS (BSN) IEEE 1 - 4 2013 [Refereed]
   

  A pedometer is a popular wearable sensor used to enumerate walking steps taken per day and in this way determines the approximate distance traveled. In this study, we used blood pressure and walking step data, obtained from 48 patients in a home healthcare system, to investigate the effectiveness of the pedometer in a clinical setting. Changes in blood pressure and walking steps per day were compared. Our results indicate that walking, as a regular form of exercise, contributed to lowering of blood pressure. Thus the pedometer is useful for improving the quality of life of patients in the home healthcare setting
• Feedback-controlled bolus plus infusion (FC-B/I) method for quantitative drug assessment in living brain with PET

  Hiroyuki Ohba; Norihiro Harada; Shingo Nishiyama; Takeharu Kakiuchi; Yuichi Kimura; Hideo Tsukada

  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM NATURE PUBLISHING GROUP 33 (1) 85 - 90 0271-678X 2013/01 [Refereed]
   

  We have developed a feedback-controlled bolus plus infusion (FC-B/I) method for monitoring the interaction between positron emission tomography (PET) ligands and their specific target molecules with PET. The usefulness of the FC-B/I method was evaluated by the direct interaction between [C-11]raclopride, a dopamine D-2 receptor (D2R) ligand, and cold raclopride (10 and 100 mu g/kg) in the brains of conscious monkeys. The present results demonstrated that the FC-B/I method could achieve the equilibrium state of [C-11]raclopride in the striatum of monkey brain, and also that the cold raclopride-induced reduction of [C-11]raclopride binding to D2R was observed in a dose-dependent manner. Good correlations of distribution volume ratio of the striatum to cerebellum between the conventional bolus plus infusion (B/I) method and the FC-B/I method as well as between the conventional bolus injection method and the FC-B/I method were observed. These results indicated that the system could be a useful tool for the evaluation of interaction between drug candidates and their target molecules like enzymes, receptors, and transporters by using of their specific PET ligands. Journal of Cerebral Blood Flow & Metabolism (2013) 33, 85-90; doi:10.1038/jcbfm.2012.134; published online 12 September 2012
• Increased Adenosine A(1) Receptor Levels in Hemianopia Patients After Cerebral Injury An Application of PET Using C-11-8-Dicyclopropylmethyl-1-Methyl-3-Propylxanthine

  Yukihisa Suzuki; Tadashi Nariai; Motohiro Kiyosawa; Manabu Mochizuki; Yuichi Kimura; Keiichi Oda; Kenji Ishii; Kiich Ishiwata

  CLINICAL NUCLEAR MEDICINE LIPPINCOTT WILLIAMS & WILKINS 37 (12) 1146 - 1151 0363-9762 2012/12 [Refereed]
   

  Purpose: The aim of this study was to apply positron emission tomography (PET) with C-11-8-dicyclopropylmethyl-1-methyl-3-propylxanthine (MPDX), a radioligand for adenosine A(1) receptor (A1R), to patients with hemianopia caused by brain injury to study neurorepair mechanisms in the brain. Patients and Methods: Four patients with homonymous hemianopia and 15 healthy subjects were examined using PET to measure cerebral glucose metabolism, C-11-flumazenil (FMZ) binding to the central benzodiazepine receptor, and MPDX binding to A1R. Left and right regions of interest (ROIs) were selected, and semiquantitative data on the 3 kinds of PET examinations were obtained. The ROIs were referenced using the data for homologous regions in the contralateral hemisphere [ipsilateral/contralateral (I/C) ratio]. Results: The I/C ratios for cerebral glucose metabolism and FMZ binding were low in the primary visual cortex (PVC) and visual association cortex in all the patients, whereas MPDX binding increased in the PVC in patients 1 and 2. Patients 1 and 2 experienced improvement in their visual field after 1 year. However, the other 2 patients showed no changes. We observed an increase in MPDX binding to A1R in the injured portion of the PVC in the patients who recovered. Conclusions: Evaluation of A1R by MPDX-PET may be useful for predicting prognosis and understanding the compensatory and reorganization processes in hemianopia caused by organic brain damage.
• Guidelines for clinical use of FDG PET, PET/CT 2012

  細野 眞; 佐賀 恒夫; 伊藤 健吾; 汲田 伸一郎; 佐々木 雅之; 千田 道雄; 畑澤 順; 渡邉 浩; 伊藤 浩; 金谷 信一; 木村 裕一; 佐治 英郎; 陣之内 正史; 福喜多 博義; 村上 康二; 絹谷 清剛; 山崎 純一; 内山 眞幸; 宇野 公一; 加藤 克彦; 川野 剛; 日下部 きよ子; 窪田 和雄; 戸川 貴史; 本田 憲業; 丸野 廣大; 吉村 真奈; 宍戸 文男; 井上 登美夫; 福田 寛; 中村 佳代子

  Jpn J Nucl Med (Kaku Igaku) (一社)日本核医学会 49 (4) 391 - 401 0022-7854 2012/11
• Differential effects of age on human striatal adenosine A1 and A2A receptors

  Masahiro Mishina; Yuichi Kimura; Mika Naganawa; Kenji Ishii; Keiichi Oda; Muneyuki Sakata; Jun Toyohara; Shiro Kobayashi; Yasuo Katayama; Kiichi Ishiwata

  SYNAPSE WILEY-BLACKWELL 66 (9) 832 - 839 0887-4476 2012/09 [Refereed]
   

  The aim of this study was to investigate the effect of age on the distribution of adenosine A1 receptors (A1Rs) and adenosine A2A receptors (A2ARs) in the striatum of healthy subjects using PET imaging with 8-dicyclopropylmethyl-1-[11C]methyl-3-propylxanthine ([11C]MPDX) and [7-methyl-11C]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine ([11C]TMSX), respectively. We recruited 8 young (22.0 +/- 1.7 years) and 10 elderly (65.4 +/- 7.6 years) volunteers to undergo [11C]MPDX PET scanning, and 11 young (22.7 +/- 2.7 years) and six elderly (60.7 +/- 8.5 years) volunteers to undergo [11C]TMSX PET scanning. A dynamic series of decay-corrected PET scans was performed for 60 min following injection of [11C]MPDX or [11C]TMSX. We calculated the binding potential (BPND) of [11C]MPDX and distribution volume ratio (DVR) of [11C]TMSX in the striatum. The BPND of [11C]MPDX was significantly lower in elderly than in young subjects, both in the putamen and head of the caudate nucleus. The BPND was negatively correlated with age in both the putamen and the head of the caudate nucleus. However, no difference was found between the DVR of [11C]TMSX in the striata of young and elderly subjects, nor was there a correlation between age and the DVR of [11C]TMSX. The effect of age on the distribution of A1Rs in the human striatum described herein is similar to previous reports of age-related decreases in dopamine D1 and D2 receptors. Unlike A1Rs, however, this study suggests that the distribution of A2ARs does not change with age. Synapse 66:832839, 2012. (c) 2012 Wiley Periodicals, Inc.
• Estimation of the linearity point in graphical analysis

  R. Todd Ogden; Yuichi Kimura

  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM NATURE PUBLISHING GROUP 32 S33 - S34 0271-678X 2012/08 [Refereed]
  
• Quantitative measurement of changes in calcium channel activity in vivo utilizing dynamic manganese-enhanced MRI (dMEMRI)

  Christoph Leuze; Yuichi Kimura; Jeff Kershaw; Sayaka Shibata; Tsuneo Saga; Kai-Hsiang Chuang; Ichiro Shimoyama; Ichio Aoki

  NEUROIMAGE ACADEMIC PRESS INC ELSEVIER SCIENCE 60 (1) 392 - 399 1053-8119 2012/03 [Refereed]
   

  The ability of manganese ions (Mn2+) to enter cells through calcium ion (Ca2+) channels has been used for depolarization dependent brain functional imaging with manganese-enhanced MRI (MEMRI). The purpose of this study was to quantify changes to Mn2+ uptake in rat brain using a dynamic manganese-enhanced MRI (dMEMRI) scanning protocol with the Patlak and Logan graphical analysis methods. The graphical analysis was based on a three-compartment model describing the tissue and plasma concentration of Mn. Mn2+ uptake was characterized by the total distribution volume of manganese (Mn) inside tissue (V-T) and the unidirectional influx constant of Mn2+ from plasma to tissue (K-i). The measurements were performed on the anterior (APit) and posterior (PPit) parts of the pituitary gland, a region with an incomplete blood brain barrier. Modulation of Ca2+ channel activity was performed by administration of the stimulant glutamate and the inhibitor verapamil. It was found that the APit and PPit showed different Mn2+ uptake characteristics. While the influx of Mn2+ into the PPit was reversible, Mn2+ was found to be irreversibly trapped in the APit during the course of the experiment. In the PPit, an increase of Mn2+ uptake led to an increase in V-T (from 2.8 +/- 0.3 ml/cm(3) to 4.6 +/- 1.2 ml/cm(3)) while a decrease of Mn2+ uptake corresponded to a decrease in V-T (from 2.8 0.3 ml/cm(3) to 1.4 +/- 0.3 ml/cm(3)). In the APit, an increase of Mn2+ uptake led to an increase in K-i (from 0.034 +/- 0.009 min(-1) to 0.049 +/- 0.012 min(-1)) while a decrease of Mn2+ uptake corresponded to a decrease in K-i (from 0.034 0.009 min(-1) to 0.019 +/- 0.003 min(-1)). This work demonstrates that graphical analysis applied to dMEMRI data can quantitatively measure changes to Mn2+ uptake following modulation of neural activity. (C) 2011 Elsevier Inc. All rights reserved.
• PET study using [C-11]FTIMD with ultra-high specific activity to evaluate I-2-imidazoline receptors binding in rat brains

  Kazunori Kawamura; Yuichi Kimura; Joji Yui; Hidekatsu Wakizaka; Tomoteru Yamasaki; Akiko Hatori; Katsushi Kumata; Masayuki Fujinaga; Yuichiro Yoshida; Masanao Ogawa; Nobuki Nengaki; Toshimitsu Fukumura; Ming-Rong Zhang

  NUCLEAR MEDICINE AND BIOLOGY ELSEVIER SCIENCE INC 39 (2) 199 - 206 0969-8051 2012/02 [Refereed]
   

  Introduction: We recently developed a selective C-11-labeled I-2-imidazoline receptor (I2R) ligand, 2-(3-fluoro-4[C-11]tolyl)-4,5-dihydro-1H-imidazole ([C-11]FTIMD). [C-11]FTIMD showed specific binding to I(2)Rs in rat brains having a high density of I2R, as well as to I(2)Rs those in monkey brains, as illustrated by positron emission tomography (PET) and autoradiography. However, [C-11]FTIMD also showed moderate non-specific binding in rat brains. In order to increase the specificity for 1,2 in rat brains, we synthesized [C-11]FTIMD with ultra-high specific activity and evaluated its binding. Methods: [C-11)FTIMD with ultra-high specific activity was prepared by a palladium-promoted cross-coupling reaction of the tributylstannyl precursor and [C-11]methyl iodide, which was produced by iodination of [C-11]methane using the single-pass method. Dynamic PET scans were conducted in rats, and the kinetic parameters were estimated. Results: [C-11]FTIMD with ultra-high specific activity was successfully synthesized with an appropriate level of radioactivity and ultra-high specific activity (4470 +/- 1660 GBq/mu mol at end of synthesis, n=11) for injection. In the PET study, distribution volume (V-T) values in all the brain regions investigated whether I2R expression was greatly reduced in BU224-pretreatead rats compared with control rats (29-45% decrease). Differences in V-T values between control and BU224-pretreated rats using [C-11]FTIMD with ultra-high specific activity were greater than those using [C-11]FTIMD with normal specific activity (17-34% decrease) in all brain regions investigated. Conclusion: Quantitative PET using [C-11]FTIMD with ultra-high specific activity can contribute to the detection of small changes in I2R expression in the brain. (C) 2012 Elsevier Inc. All rights reserved.
• Relationship between whole body oxygen consumption and skeletal muscle glucose metabolism during walking in older adults: FDG PET study

  Hiroyuki Shimada; Daina Sturnieks; Yosuke Endo; Yuichi Kimura; Takao Suzuki; Keiichi Oda; Kenji Ishii; Kiichi Ishiwata

  AGING CLINICAL AND EXPERIMENTAL RESEARCH EDITRICE KURTIS S R L 23 (3) 175 - 182 1594-0667 2011/06 [Refereed]
   

  Background and aims: The purpose of this study was to determine the relationship between whole body energy metabolism measured as oxygen consumption (VO(2)) and local muscle activity measured by positron emission tomography (PET) and [(18)F]fluorodeoxyglucose (FDG). Methods: Ten community-dwelling older women (73-83 yrs) had FDG PET and VO(2) measured while walking at a comfortable speed. Results: A significant positive correlation was found between VO(2) and FDG uptake in the biceps femoris (r=0.83), gluteus minimus (r=0.67), gluteus medius (r=0.77) and pelvis section muscles (r=0.76). The subjects who showed high FDG uptake in the hip muscle group had significantly higher VO(2) while walking, compared with subjects without high FDG uptake in the hip muscles. Conclusions: These results indicate that FDG PET provides an index which reflects whole body energy metabolism during walking, and revealed that excess muscle activity in the hip muscles during walking plays a key role in increasing VO(2) in older adults. (Aging Clin Exp Res 2011; 23:175-182) (c) 2011, Editrice Kurtis
• Evaluation of Limiting Brain Penetration Related to P-glycoprotein and Breast Cancer Resistance Protein Using [C-11]GF120918 by PET in Mice

  Kazunori Kawamura; Tomoteru Yamasaki; Fujiko Konno; Joji Yui; Akiko Hatori; Kazuhiko Yanamoto; Hidekatsu Wakizaka; Makoto Takei; Yuichi Kimura; Toshimitsu Fukumura; Ming-Rong Zhang

  MOLECULAR IMAGING AND BIOLOGY SPRINGER 13 (1) 152 - 160 1536-1632 2011/02 [Refereed]
   

  GF120918 has a high inhibitory effect on P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP). We developed [C-11]GF120918 as a positron emission tomography (PET) probe to assess if dual modulation of P-gp and BCRP is useful to evaluate brain penetration. PET studies using [C-11]GF120918 were conducted on P-gp and/or Bcrp knockout mice as well as wild-type mice. In PET studies, the AUC(brain) ([0-60 min]) and K (1) value in P-gp/Bcrp knockout mice were nine- and 26-fold higher than that in wild-type mice, respectively. These results suggest that brain penetration of [C-11]GF120918 is related to modulation of P-gp and BCRP and is limited by two transporters working together. PET using [C-11]GF120918 may be useful for evaluating the function of P-gp and BCRP. PET using P-gp/Bcrp knockout mice may be an effective method to understand the overall contributions the functions of P-gp and BCRP.
• Adenosine A(2A) Receptors Measured with [C-11]TMSX PET in the Striata of Parkinson's Disease Patients

  Masahiro Mishina; Kiichi Ishiwata; Mika Naganawa; Yuichi Kimura; Shin Kitamura; Masahiko Suzuki; Masaya Hashimoto; Kenji Ishibashi; Keiichi Oda; Muneyuki Sakata; Makoto Hamamoto; Shiro Kobayashi; Yasuo Katayama; Kenji Ishii

  PLOS ONE PUBLIC LIBRARY SCIENCE 6 (2) e17338  1932-6203 2011/02 [Refereed]
   

  Adenosine A(2A) receptors (A2ARs) are thought to interact negatively with the dopamine D2 receptor (D2R), so selective A2AR antagonists have attracted attention as novel treatments for Parkinson's disease (PD). However, no information about the receptor in living patients with PD is available. The purpose of this study was to investigate the relationship between A2ARs and the dopaminergic system in the striata of drug-naive PD patients and PD patients with dyskinesia, and alteration of these receptors after antiparkinsonian therapy. We measured binding ability of striatal A2ARs using positron emission tomography (PET) with [7-methyl-C-11]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine ([C-11]TMSX) in nine drug-naive patients with PD, seven PD patients with mild dyskinesia and six elderly control subjects using PET. The patients and eight normal control subjects were also examined for binding ability of dopamine transporters and D2Rs. Seven of the drug-naive patients underwent a second series of PET scans following therapy. We found that the distribution volume ratio of A2ARs in the putamen were larger in the dyskinesic patients than in the control subjects (p < 0.05, Tukey-Kramer post hoc test). In the drug-naive patients, the binding ability of the A2ARs in the putamen, but not in the head of caudate nucleus, was significantly lower on the more affected side than on the less affected side (p < 0.05, paired t-test). In addition, the A2ARs were significantly increased after antiparkinsonian therapy in the bilateral putamen of the drug-naive patients (p < 0.05, paired t-test) but not in the bilateral head of caudate nucleus. Our study demonstrated that the A2ARs in the putamen were increased in the PD patients with dyskinesia, and also suggest that the A2ARs in the putamen compensate for the asymmetrical decrease of dopamine in drug-naive PD patients and that antiparkinsonian therapy increases the A2ARs in the putamen. The A2ARs may play an important role in regulation of parkinsonism in PD.
• 50-Year Anniversary of JSMBE

  KIMURA Yuichi

  BME Japanese Society for Medical and Biological Engineering 49 (2) 375 - 375 1347-443X 2011
• パラメトリック固有空間を利用したPET動態データの雑音除去

  星野直輝; 本谷秀堅; 坂口和也; 坂田宗之; 石渡喜一; 木村裕一

  Med Imaging Tech 13 (1) 152 - 160 2011 [Refereed]
  
• Denoising for PET Dynamic Data using Parametric Eigenspace

  N. Hoshino; H. Hontani; K. Sakaguchi; M. Sakata; K. Ishiwata; Y. Kimura

  日本医用画像工学会論文誌 28 (5) 362 - 370 2185-3193 2010/11 [Refereed]
  
• Automatic controlled bolus plus infusion method for reliable quantitative drug assessment

  Hiroyuki Ohba; Shingo Nishiyama; Takeharu Kakiuchi; Norihiro Harada; Yuichi Kimura; Hideo Tsukada

  NEUROIMAGE ACADEMIC PRESS INC ELSEVIER SCIENCE 52 S28 - S28 1053-8119 2010/08 [Refereed]
  
• Imaging of I-2-imidazoline receptors by small-animal PET using 2-(3-fluoro-[4-C-11]tolyl)-4,5-dihydro-1H-imidazole ([C-11]FTIMD)

  Kazunori Kawamura; Mika Naganawa; Fujiko Konno; Joji Yui; Hidekatsu Wakizaka; Tomoteru Yamasaki; Kazuhiko Yanamoto; Akiko Hatori; Makoto Takei; Yuichiro Yoshida; Kazuya Sakaguchi; Toshimitsu Fukumura; Yuichi Kimura; Ming-Rong Zhang

  NUCLEAR MEDICINE AND BIOLOGY ELSEVIER SCIENCE INC 37 (5) 625 - 635 0969-8051 2010/07 [Refereed]
   

  Introduction: Imidazoline receptors (IRs) have been established as distinct receptors, and have been categorized into at least two subtypes (I1R and I2R). I(2)Rs are associated with depression, Alzheimer's disease, Huntington's disease and Parkinson's disease. A few positron emission tomography (PET) probes for I(2)Rs have been synthesized, but a selective PET probe has not been evaluated for the imaging of I(2)Rs by PET. We labeled a selective I2R ligand 2-(3-fluoro-4-tolyl)-4,5-dihydro-1H-imidazole (FTIMD) with C-11 and performed the first imaging of I(2)Rs by PET using 2-(3-fluoro-[4-C-11]tolyl)-4,5-dihydro-1H-imidazole ([C-11]FTIMD). Methods: [C-11]FTIMD was prepared by a palladium-promoted cross-coupling reaction of the tributylstannyl precursor and [C-11]methyl iodide in the presence of tris(dibenzylideneacetone)dipalladium(0) and tri(o-tol)phosphine. Biodistribution was investigated in rats by tissue dissection. [C-11]FTIMD metabolites were measured in brain tissues and plasma. Dynamic PET scans were acquired in rats, and the kinetic parameters estimated. Results: [C-11]FTIMD was successfully synthesized with a suitable radioactivity for the injection. Co-injection with 0.1 mg/kg of cold FTIMD and BU224 induced a significant reduction in the brain-to-blood ratio 15 and 30 mm after the injection. In metabolite analysis, unchanged [C-11]FTIMD in the brain was high (98%) 30 min after the injection. In PET studies, high radioactivity levels were observed in regions with a high density of I2R. The radioactivity levels and V-T values in the brain regions were prominently reduced by 1.0 mg/kg of BU224 pretreatment as compared with control. Conclusion: [C-11]FTIMD showed specific binding to I(2)Rs in rat brains with a high density of I2R. (C) 2010 Elsevier Inc. All rights reserved.
• A small animal holding fixture system with positional reproducibility for longitudinal multimodal imaging

  Daisuke Kokuryo; Yuichi Kimura; Takayuki Obata; Taiga Yamaya; Kazunori Kawamura; Ming-Rong Zhang; Iwao Kanno; Ichio Aoki

  PHYSICS IN MEDICINE AND BIOLOGY IOP PUBLISHING LTD 55 (14) 4119 - 4130 0031-9155 2010/07 [Refereed]
   

  This study presents a combined small animal holding fixture system, termed a 'bridge capsule', which provides for small animal re-fixation with positional reproducibility. This system comprises separate holding fixtures for the head and lower body and a connecting part to a gas anesthesia system. A mouse is fixed in place by the combination of a head fixture with a movable part made from polyacetal resin, a lower body fixture made from vinyl-silicone and a holder for the legs and tail. For re-fixation, a similar posture could be maintained by the same holding fixtures and a constant distance between the head and lower body fixtures is maintained. Artifacts caused by the bridge capsule system were not observed on magnetic resonance (MRI) and positron emission tomography (PET) images. The average position differences of the spinal column and the iliac body before and after re-fixation for the same modality were approximately 1.1 mm. The difference between the MRI and PET images was approximately 1.8 mm for the lower body fixture after image registration using fiducial markers. This system would be useful for longitudinal, repeated and multimodal imaging experiments requiring similar animal postures.
• Development of PET radiopharmaceuticals and their clinical applications at the Positron Medical Center

  Kiichi Ishiwata; Yuichi Kimura; Keiichi Oda; Kenji Ishii; Muneyuki Sakata; Keiichi Kawasaki; Tadashi Nariai; Yukihisa Suzuki; Kenji Ishibashi; Masahiro Mishina; Masaya Hashimoto; Masatomo Ishikawa; Jun Toyohara

  GERIATRICS & GERONTOLOGY INTERNATIONAL WILEY-BLACKWELL 10 S180 - S196 1444-1586 2010/07 [Refereed]
   

  The Positron Medical Center has developed a large number of radiopharmaceuticals and 36 radiopharmaceuticals have been approved for clinical use for studying aging and geriatric diseases, especially brain functions. Positron emission tomography (PET) has been used to provide a highly advanced PET-based diagnosis. The current status of the development of radiopharmaceuticals, and representative clinical and methodological results are reviewed. Geriatr Gerontol Int 2010; 10 (Suppl. 1): S180-S196.
• Quantitative analysis of dopamine transporters in human brain using [C-11]PE2I and positron emission tomography: evaluation of reference tissue models

  Chie Seki; Hiroshi Ito; Tetsuya Ichimiya; Ryosuke Arakawa; Yoko Ikoma; Miho Shidahara; Jun Maeda; Akihiro Takano; Hidehiko Takahashi; Yuichi Kimura; Kazutoshi Suzuki; Iwao Kanno; Tetsuya Suhara

  ANNALS OF NUCLEAR MEDICINE SPRINGER 24 (4) 249 - 260 0914-7187 2010/05 [Refereed]
   

  Dopamine transporter (DAT) is a reuptake carrier of dopamine at presynapse that regulates dopaminergic neural transmission. [C-11]PE2I is a cocaine analog developed as a potent positron emission tomography (PET) ligand for DAT with high selectivity. The aim of this study was to evaluate the applicability of quantification methods using reference tissue models for [C-11]PE2I. Dynamic PET scans were performed in 6 young healthy male volunteers after an intravenous bolus injection of [C-11]PE2I. Metabolite-corrected arterial plasma-input functions were obtained. Compartment model analysis and plasma-input Logan analysis were performed to determine the kinetic parameters and distribution volume (V (T)). The distribution volume ratio (DVR) was calculated as the ratio of V (T) in the cerebral region to that in the cerebellum. DVRs were also determined by the original multilinear reference tissue model method (MRTMo) and the simplified reference tissue model method (SRTM), comparing the results with those obtained from graphical analysis using arterial input function. To estimate errors in DVR calculated using the reference tissue model, a simulation study that focused on cerebellar kinetics and scan duration was performed. The highest [C-11]PE2I binding was observed in the striatum, followed by the midbrain and thalamus. The 2-tissue model was preferable to the 1-tissue model for describing the [C-11]PE2I kinetics in the cerebellum. Both the measured and 90-min simulated data showed that reference tissue models caused an underestimation of DVR in the striatum. The simulation showed that 90-min scan duration was insufficient when cerebellar kinetics was described as a 1-tissue model. Nevertheless, DVR values determined by MRTMo and SRTM were in good agreement with those by the graphical approach in other lower binding regions. Due to the [C-11]PE2I kinetics in the cerebellum and limited scan duration for C-11, MRTMo and SRTM underestimated the striatal DVR. Despite this limitation, the present study demonstrated the applicability of reference tissue models. Since DAT in the midbrain and thalamus is of interest in the pathophysiology of neuropsychiatric disease, this noninvasive quantitative analysis will be useful for clinical investigations.
• Measurement error analysis for the determination of dopamine D-2 receptor occupancy using the agonist radioligand [C-11]MNPA

  Miho Shidahara; Hiroshi Ito; Tatsui Otsuka; Yoko Ikoma; Ryosuke Arakawa; Fumitoshi Kodaka; Chie Seki; Harumasa Takano; Hidehiko Takahashi; Federico E. Turkheimer; Yuichi Kimura; Iwao Kanno; Tetsuya Suhara

  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM NATURE PUBLISHING GROUP 30 (1) 187 - 195 0271-678X 2010/01 [Refereed]
   

  The purpose of this study is to investigate errors in quantitative analysis for estimating dopamine D-2 receptor occupancy of antipsychotics with agonist radioligand [C-11]MNPA by numerical simulation, with particular attention to the validity of a quantitative approach based on the use of a reference region. Synthetic data were validated using clinical data combined with a bootstrap approach. Time-activity curves (TACs) of [C-11]MNPA were simulated, and the reliability of binding potential (BPND) and occupancy estimated by nonlinear least square (NLS) fitting and a simplified reference tissue model (SRTM) were investigated for various noise levels and scan durations. In the human positron emission tomography (PET) study with and without antipsychotic, risperidone, the uncertainty of BPND and occupancy estimated by SRTM was investigated using resampled TACs based on bootstrap approach with weighted residual errors of fitting. For both NLS and SRTM, it was possible to have < 3% of bias in occupancy estimates of [C-11]MNPA by 60 mins. However, shortened scan duration degrades the quantification of very small binding potentials, especially in case of SRTM. Observations were replicated on the clinical data. Results showed that dopamine D-2 receptor occupancy by antipsychotics can be estimated precisely in region of interest analysis by SRTM with a longer than 60-min [C-11]MNPA PET scan duration. Journal of Cerebral Blood Flow & Metabolism (2010) 30, 187-195; doi: 10.1038/jcbfm.2009.193; published online 16 September 2009
• A new graphic plot analysis for determination of neuroreceptor binding in positron emission tomography studies

  Hiroshi Ito; Takashi Yokoi; Yoko Ikoma; Miho Shidahara; Chie Seki; Mika Naganawa; Hidehiko Takahashi; Harumasa Takano; Yuichi Kimura; Masanori Ichise; Tetsuya Suhara

  NEUROIMAGE ACADEMIC PRESS INC ELSEVIER SCIENCE 49 (1) 578 - 586 1053-8119 2010/01 [Refereed]
   

  In positron emission tomography (PET) studies with radioligands for neuroreceptors, tracer kinetics have been described by the standard two-tissue compartment model that includes the compartments of nondisplaceable binding and specific binding to receptors. In the present Study, we have developed a new graphic plot analysis to determine the total distribution volume (V(T)) and nondisplaceable distribution volume (V(ND)) independently, and therefore the binding potential (BP(ND)). In this plot, Y(t) is the ratio of brain tissue activity to time-integrated arterial input function, and X(t) is the ratio of time-integrated brain tissue activity to time-integrated arterial input function. The x-intercept of linear regression of the plots for early phase represents V(ND), and the x-intercept of linear regression of the plots for delayed phase after the equilibrium time represents V(T). BP(ND) can be calculated by BP(ND) = V(T)/V(ND) - 1. Dynamic PET scanning with measurement of arterial input function was performed on six healthy men after intravenous rapid bolus injection of [(11)C]FLB457. The plot yielded a curve in regions with specific binding while it yielded a straight line through all plot data in regions with no specific binding. V(ND), V(T), and BP(ND) values calculated by the present method were in good agreement with those by conventional non-linear least-squares fitting procedure. This method can be used to distinguish graphically whether the radioligand binding includes specific binding or not. (C) 2009 Elsevier Inc. All rights reserved.
• Effects of a robotic walking exercise on walking performance in community-dwelling elderly adults

  Hiroyuki Shimada; Takashi Hirata; Yuichi Kimura; Takako Naka; Keishiro Kikuchi; Keiichi Oda; Kenji Ishii; Kiichi Ishiwata; Takao Suzuki

  GERIATRICS & GERONTOLOGY INTERNATIONAL WILEY-BLACKWELL PUBLISHING, INC 9 (4) 372 - 381 1444-1586 2009/12 [Refereed]
   

  Background: Reduced gait speed and stride length are characteristic of gait in elderly people and increase their dependency on assistance. We developed a robotic stride assistance system (SAS) to automatically control the walk ratio during walking. Our aim was to quantify the effects of a walking exercise with the SAS on walking performance and glucose metabolism during walking in community-dwelling elderly adults. Methods: For 3 months, 15 women (72-85 years old) performed the walking exercise twice weekly for 90 min/session. We assessed walking for 5 m at a comfortable speed before and after the intervention. Positron emission tomography with [18F]fluorodeoxyglucose (FDG) was used to assess muscle activity during an unassisted 50-min walk. Results: Walking speed was improved by the intervention and FDG uptake by the gluteus minimus, gluteus medius and rectus femoris, and pelvic muscles (iliacus and gluteus muscles) were reduced. Conclusion: These results suggest that a walking intervention program using an applied robotic system is useful for improving the walking ability and the efficiency of muscle activities during walking in the elderly.
• Biomedical Engineering Symposium 2009

  TAMURA Toshiyo; KIMURA Yuichi

  BME Japanese Society for Medical and Biological Engineering 47 (5) 470 - 470 1347-443X 2009/10
• High occupancy of sigma(1) receptors in the human brain after single oral administration of donepezil: a positron emission tomography study using [C-11]SA4503

  Masatomo Ishikawa; Muneyuki Sakata; Kenji Ishii; Yuichi Kimura; Keiichi Oda; Jun Toyohara; Jin Wu; Kiichi Ishiwata; Masaomi Iyo; Kenji Hashimoto

  INTERNATIONAL JOURNAL OF NEUROPSYCHOPHARMACOLOGY CAMBRIDGE UNIV PRESS 12 (8) 1127 - 1131 1461-1457 2009/09 [Refereed]
   

  The acetylcholinesterase (AChE) inhibitor donepezil is also a sigma(1) receptor agonist. We examined whether donepezil binds to a, receptors in the living human brain after a single oral administration. Dynamic positron emission tomography (PET) data acquisition using the selective sigma(1) receptor ligand [C-11]SA4503 was performed to evaluate quantitatively the binding of [C-11]SA4503 to at receptors in eight healthy male volunteers. Each subject had a PET scan before and after receiving a single dose of donepezil (5 or 10 mg). The binding potential of [C-11]SA4503 was calculated. Doses of 5 mg and 10 mg donepezil bound to a, receptors in the human brain with occupancies of similar to 60% and similar to 75%, respectively, in a dose-dependent manner. This study demonstrated that donepezil binds to sigma(1) receptors in the Living human brain at therapeutic doses. Therefore, sigma(1) receptors may be implicated in the pharmacological mechanism of donepezil in the human brain.
• PET pharmacokinetic analysis to estimate boron concentration in tumor and brain as a guide to plan BNCT for malignant cerebral glioma.

  Tadashi Nariai; Kiichi Ishiwata; Yuichi Kimura; Motoki Inaji; Toshiya Momose; Tetsuya Yamamoto; Akira Matsumura; Kenji Ishii; Kikuo Ohno

  Appl Radiat Isot 67 (7-8 Suppl) S348 - S350 1872-9800 2009/07 

  To plan the optimal BNCT for patients with malignant cerebral glioma, estimation of the ratio of boron concentration in tumor tissue against that in the surrounding normal brain (T/N ratio of boron) is important. We report a positron emission tomography (PET) imaging method to estimate T/N ratio of tissue boron concentration based on pharmacokinetic analysis of amino acid probes.
  Twelve patients with cerebral malignant glioma underwent 60 min dynamic PET scanning of brain after bolus injection of (18)F-borono-phenyl-alanine (FBPA) with timed arterial blood sampling. Using kinetic parameter obtained by this scan, T/N ratio of boron concentration elicited by one-hour constant infusion of BPA, as performed in BNCT, was simulated on Runge-Kutta algorithm. (11)C-methionine (MET) PET scan, which is commonly used in worldwide PET center as brain tumor imaging tool, was also performed on the same day to compare the image characteristics of FBPA and that of MET.
  PET glioma images obtained with FBPA and MET are almost identical in all patients by visual inspection. Estimated T/N ratio of tissue boron concentration after one-hour constant infusion of BPA, T/N ratio of FBPA on static condition
• PET pharmacokinetic analysis to estimate boron concentration in tumor and brain as a guide to plan BNCT for malignant cerebral glioma

  Tadashi Nariai; Kiichi Ishiwata; Yuichi Kimura; Motoki Inaji; Toshiya Momose; Tetsuya Yamamoto; Akira Matsumura; Kenji Ishii; Kikuo Ohno

  APPLIED RADIATION AND ISOTOPES PERGAMON-ELSEVIER SCIENCE LTD 67 (7-8) S348 - S350 0969-8043 2009/07 [Refereed]
   

  Introduction: To plan the optimal BNCT for patients with malignant cerebral glioma, estimation of the ratio of boron concentration in tumor tissue against that in the surrounding normal brain (T/N ratio of boron) is important. We report a positron emission tomography (PET) imaging method to estimate T/N ratio of tissue boron concentration based on pharmacokinetic analysis of amino acid probes. Methods: Twelve patients with cerebral malignant glioma underwent 60 min dynamic PET scanning of brain after bolus injection of (18)F-borono-phenyl-alanine (FBPA) with timed arterial blood sampling. Using kinetic parameter obtained by this scan, T/N ratio of boron concentration elicited by one-hour constant infusion of BPA, as performed in BNCT, was simulated on Runge-Kutta algorithm. (11)C-methionine (MET) PET scan, which is commonly used in worldwide PET center as brain tumor imaging tool, was also performed on the same day to compare the image characteristics of FBPA and that of MET. Result: PET glioma images obtained with FBPA and MET are almost identical in all patients by visual inspection. Estimated T/N ratio of tissue boron concentration after one-hour constant infusion of BPA, T/N ratio of FBPA on static condition, and T/N ratio of MET on static condition showed significant linear correlation between each other. Conclusion: T/N ratio of boron concentration that is obtained by constant infusion of BPA during BNCT can be estimated by FBPA PET scan. This ratio can also be estimated by MET-PET imaging. As MET-PET study is available in many clinical PET center, selection of candidates for BNCT may be possible by MET-PET images. Accurate planning of BNCT may be performed by static images of FBPA PET. Use of PET imaging with amino acid probes may contribute very much to establish an appropriate application of BNCT for patients with malignant glioma. (C) 2009 Elsevier Ltd. All rights reserved.
• A statistical clustering approach to visualizing the relationship between early and delayed images in whole-body FDG-PET

  Keiichi Oda; Hinako Toyama; Yasuoki Mashima; Kenji Ishii; Toru Kosaka; Yuichi Kimura; Masahiro Fukushi; Kiichi Ishiwata

  Radiological Physics and Technology 2 (2) 145 - 150 1865-0333 2009/07 [Refereed]
   

  We propose a new method for diagnostic assistance in oncology, [fluorine-18]-2-fluoro-2-deoxy-d-glucose (FDG)-positron emission tomography (PET). Early and delayed scans were performed on 10 patients with lung cancer by use of an ECAT EXACT 47 PET scanner, and standardized-uptake-value (SUV) images were created. Three segmentation (S1, S2, and S3) maps were created from the early and delayed SUV images according to various thresholds (SUV threshold = 2.0, 2.5, and 3.0) based on the early image and the percentage change defined as (SUVdelayed - SUVearly) × 100/SUVearly. Voxels that had larger voxel values in their early images than the SUVthreshold were clustered into three classes: S1 if the percentage change was larger than 10, S2 if the percentage change was between 0 and 10, and S3 if the percentage change was negative. The S1 segments showed malignant lesions clearly however, the S2 segments showed an SUV that had decreased from the S1 areas due to the partial volume effect or misalignment between the early and delayed scans. The S3 areas showed benignity or physiologic accumulation. The segmented images, S1, S2, and S3, were useful for clinical diagnosis with dual-phase FDG-PET scans and offer an easy way of exploring the longitudinal alteration in the SUV. © 2009 Japanese Society of Radiological Technology and Japan Society of Medical Physics.
• Comparison of regional lower limb glucose metabolism in older adults during walking

  H. Shimada; Y. Kimura; S. R. Lord; K. Oda; K. Ishii; T. Suzuki; K. Ishiwata

  SCANDINAVIAN JOURNAL OF MEDICINE & SCIENCE IN SPORTS WILEY-BLACKWELL PUBLISHING, INC 19 (3) 389 - 397 0905-7188 2009/06 [Refereed]
   

  Glucose metabolism in lower limb muscles during walking has an important role in gait efficiency and endurance. The purpose of this study was to identify differences in muscle activity during walking between healthy young and older adults using positron emission tomography (PET) and [(18)F]fluorodeoxyglucose (FDG). Ten healthy young men (24 +/- 2 years) and 10 healthy older men (76 +/- 2 years) participated in this study. An FDG PET assessment of each subject was conducted after 50 min of treadmill walking. The images of glucose metabolism in 18 regions of interest were estimated from the standardized uptake value (SUV). The older adults showed a significantly higher FDG uptake in the semitendinosus, biceps femoris, iliacus, gluteus minimus, gluteus medius, and gluteus maximus muscles than the young adults: FDG uptake ratios of SUV in the old to SUV in the young were 3.02, 3.19, 1.66, 1.64, 3.68, and 3.05, respectively. During walking, the FDG uptake in older adults was higher in hamstrings and deep layer hip muscles than that in young adults. These results suggest that intervention to facilitate efficient muscle activity during walking should be practiced to improve gait endurance in older adults with impaired walking patterns.
• Improvement of likelihood estimation in Logan graphical analysis using maximum a posteriori for neuroreceptor PET imaging

  Miho Shidahara; Chie Seki; Mika Naganawa; Muneyuki Sakata; Masatomo Ishikawa; Hiroshi Ito; Iwao Kanno; Kiichi Ishiwata; Yuichi Kimura

  ANNALS OF NUCLEAR MEDICINE SPRINGER 23 (2) 163 - 171 0914-7187 2009/02 [Refereed]
   

  To reduce variance of the total volume of distribution (V (T)) image, we improved likelihood estimation in graphical analysis (LEGA) for dynamic positron emission tomography (PET) images using maximum a posteriori (MAP). In our proposed MAP estimation in graphical analysis (MEGA), a set of time-activity curves (TACs) was formed with V (T) varying in physiological range as a template, and then the most similar TAC was sought out for a given measured TAC in a feature space. In simulation, MEGA was compared with other three methods, Logan graphical analysis (GA), multilinear analysis (MA1), and LEGA using 500 noisy TACs, under each of seven physiological conditions (from 9.9 to 61.5 of V (T)). PET studies of [(11)C]SA4503 were performed in three healthy volunteers. In clinical studies, the V (T) images estimated from MEGA were compared with region of interest (ROI) estimates from a nonlinear least square (NLS) fitting over four brain regions. In the simulation study, the estimated V (T) by GA had a large underestimation (y = 0.27x + 8.72, r (2) = 0.87). Applying the other methods (MA1, LEGA, and MEGA), these noise-induced biases were improved (y = 0.80x + 4.04, r (2) = 0.98; y = 0.85x + 3.05, r (2) = 0.99; y = 0.96x + 1.21, r (2) = 0.99, respectively). MA1 and LEGA produced increased variance of the estimated V (T) in clinical studies. However, MEGA improved signal-to-noise ratio (SNR) in V (T) images with linear correlations between ROI estimates with NLS (y = 0.87x + 5.1, r (2) = 0.96). MEGA was validated as an alternative strategy of LEGA to improve estimates of V (T) in clinical PET imaging.
• Adenosine A(1) receptors using 8-dicyclopropylmethyl-1-[C-11]methyl-3-propylxanthine PET in Alzheimer's disease

  Nobuyoshi Fukumitsu; Kenji Ishii; Yuichi Kimura; Keiichi Oda; Masaya Hashimoto; Masahiko Suzuki; Kiichi Ishiwata

  ANNALS OF NUCLEAR MEDICINE SPRINGER 22 (10) 841 - 847 0914-7187 2008/12 [Refereed]
   

  Adenosine is an endogenous modulator of synaptic functions in the central nervous system. The effects of adenosine are mediated by at least four adenosine receptor subtypes. Decreased density of adenosine A1 receptors, which is a major subtype adenosine receptor in the hippocampus, has been reported in vitro in Alzheimer's disease. We evaluated adenosine A1 receptor in the brain of elderly normal subjects and patients with Alzheimer's disease (n = 8 and 6, respectively), using positron emission tomography (PET) and 8- dicyclopropylmethyl-1-[C-11]methyl-3-propylxanthine ([C-11]MPDX). A 60-min PET scan with [C-11]MPDX was performed. The patients with Alzheimer's disease also underwent PET with [F-18]fluorodeoxyglucose (FDG). The binding potential of [11C]MPDX was quantitatively calculated in the regions of interest (ROIs) placed on the frontal, medial frontal, temporal, medial temporal, parietal, and occipital cortices, striatum, thalamus, cerebellum, and pons. Statistical parametric mapping (SPM2) was used for analysis of [C-11]MPDX and FDG-PET. In the ROI-based analysis, the binding potential of [C-11]MPDX in patients with Alzheimer's disease was significantly lower in the temporal and medial temporal cortices and thalamus than that in elderly normal subjects (P = 0.038, 0.028, and 0.039, respectively). SPM analysis also showed significant decreased binding potential in the temporal and medial temporal cortices and thalamus in patients with Alzheimer's disease. FDG uptake was significantly decreased in the temporoparietal cortex and posterior cingulate gyrus. Decreased binding of [C-11]MPDX in patients with Alzheimer's disease was detected in temporal and medial temporal cortices and thalamus. This pattern possibly differed from the hypometabolism pattern of FDG. [C-11]MPDX PET is valuable for the detection of degeneration in the temporal and medial temporal cortices and corticothalamic transmission, and may provide a different diagnostic tool from FDG-PET in brain disorders such as Alzheimer's disease.
• Effects of an automated stride assistance system on walking parameters and muscular glucose metabolism in elderly adults

  H. Shimada; T. Suzuki; Y. Kimura; T. Hirata; M. Sugiura; Y. Endo; K. Yasuhara; K. Shimada; K. Kikuchi; K. Oda; K. Ishii; K. Ishiwata

  BRITISH JOURNAL OF SPORTS MEDICINE B M J PUBLISHING GROUP 42 (11) 922 - 929 0306-3674 2008/11 [Refereed]
   

  Objective: To identify the effects of an automated stride assistance system (SAS) on walking scores and muscle activities in the lower extremities of elderly people. Methods: Seven healthy elderly men (73 -81 years) participated in this study. Subjects walked continuously at a constant speed for 50 min on a treadmill with and without the SAS, which is a device to control the walk ratio (step length/cadence) and to add support power to the thigh during walking. A step counter equipped with an infrared device was used to record walking data. The average speeds during treadmill walking were 2.89 -3.82 km/h without the SAS and 3.03-4.03 km/h with the SAS. Positron emission tomography (PET) and [(18)F] fluorodeoxyglucose (FDG) evaluation of glucose metabolism were conducted on each subject twice after walking with and without the SAS. Results: Walk ratio, walking speed and step length were significantly improved in all subjects by the SAS, while cadence was significantly decreased by the SAS in all subjects except one. The SAS did not have a significant effect on glucose metabolism of the muscles of the lower extremities. There were no significant correlations between change in walking speed and change in glucose metabolism in each muscle without the SAS and with the SAS. In contrast, significant correlations between walking speed and glucose metabolism were shown in gluteus minimus (r= -0.929), hip-related muscles (r= -0.862), soleus (r= -0.907), and medial gastrocnemius (r= -0.952) without the SAS. With the SAS, there were significant correlations in gluteus medius (r= -0.899), hip-related muscles (r= -0.819), and medial gastrocnemius (r= -0.817) in the elderly subjects. Conclusions: The SAS increases walking scores in elderly people without increasing energy consumption of lower-extremity muscles. The elderly subjects with low walking speed showed higher glucose metabolism in hiprelated muscles and triceps surae. Thus, this association suggested that decreased walking speed in elderly adults has a higher metabolic cost in these muscle regions.
• Error analysis for PET measurement of dopamine D(2) receptor occupancy by antipsychotics with [(11)C]raclopride and [(11)C]FLB 457

  Yoko Ikoma; Hiroshi Ito; Ryosuke Arakawa; Masaki Okumura; Chie Seki; Miho Shidahara; Hidehiko Takahashi; Yuichi Kimura; Iwao Kanno; Tetsuya Suhara

  NEUROIMAGE ACADEMIC PRESS INC ELSEVIER SCIENCE 42 (4) 1285 - 1294 1053-8119 2008/10 [Refereed]
   

  Dopamine D(2) receptor occupancy by antipsychotic drugs has been measured with positron emission tomography (PET) by comparing the binding potential (BP) values before and after drug administration. This occupancy has been found to be related to clinical effects and side effects. in this study, we evaluated the in simulation and human studies of [(11)C]raclopride and for the high affinity ligand [(11)C]FLB 457. Time-activity curves of [(11)C]raclopride and [(11)C]FLB 457 were simulated, and the reliability of BP estimated by a simplified reference tissue model and the calculated Occupancy were investigated for various noise levels, BP values, and scan durations. Then, in the human PET study with and without antipsychotics, the uncertainty of BP and occupancy estimates and the scan duration required for a reliable estimation were investigated by a bootstrap approach. Reliable and unbiased estimates of [(11)C]raclopride BP(ND) could be obtained with recording as short as 32 min, with the relative standard deviation (SD) of the striatal occupancy remaining less than 10%. Conversely, in [(11)C]FLB 457 Studies, the mean value increased and SD of the temporal cortex and thalamus exceeded 10% when the scan duration was shorter than 60 min. These results demonstrated that dopamine D(2) receptor occupancy by antipsychotics can be estimated precisely with an optimal scan duration with [(11)C]raclopride and [(11)C]FLB 457. (C) 2008 Elsevier Inc. All rights reserved.
• Successive positron emission tomography measurement of cerebral blood flow and neuroreceptors in the human brain: an (11)C-SA4503 study

  Kiichi Ishiwata; Kenji Ishii; Yuichi Kimura; Kazunori Kawamura; Keiichi Oda; Toru Sasaki; Muneyuki Sakata; Michio Senda

  ANNALS OF NUCLEAR MEDICINE SPRINGER 22 (5) 411 - 416 0914-7187 2008/06 [Refereed]
   

  For evaluating a newly developed radioligand for positron emission tomography (PET), successive measurements of regional cerebral blood flow (rCBF) and the kinetics of the radioligand in the same subject are preferable in the first clinical trial. In this study, we demonstrate an example for the study of (11)C-labeled 1-(3,4-dimethoxyphenethyl)-4-(3-phenylprophyl) piperazine ((11)C-SA4503) for mapping sigma(1) receptors in the human brain. Five healthy male subjects underwent two successive PET scans with (15)O-H(2)O to measure the rCBF and with (11)C-SA4503 (dynamic 60-min scan). The brain kinetics of (11)C-SA4503 was evaluated using the time-activity curve (TAC) of tissue in each of the 11 regions of the brain and the metabolite-corrected TAC of plasma on the basis of a two-tissue compartment fourparameter model. The estimated parameters were four rate constants: K (1), influx from plasma to brain tissue; k (2), efflux from tissue to plasma; k (3), association between tracer and receptors; and k (4), dissociation of tracer-receptor complex, and the binding potential (BP), k (3)/k (4). (11)CSA4503 was distributed all over the brain, and the TACs exhibited an accumulation pattern in all the 11 regions. K (1) of (11)C-SA4503 correlated with rCBF, but the other three rate constant parameters and BP did not. The regional difference in the BP of (11)C-SA4503 is compatible with those of sigma(1) receptors. In conclusion, successive PET measurements of rCBF and the brain kinetics of radioligand-neuroreceptor binding are useful for the first clinical trial of a newly developed radioligand for mapping neuroreceptors, and the protocol is applicable to pathophysiological studies of brain disorders.
• Measurement of the C-11-flumazenil binding in the visual cortex predicts the prognosis of hemianopia

  Yukihisa Suzuki; Chiharu Horie; Motohiro Kiyosawa; Tadashi Nariai; Manabu Mochizuki; Keiichi Oda; Yuichi Kimura; Kiich Ishiwata; Kenji Ishii

  JOURNAL OF THE NEUROLOGICAL SCIENCES ELSEVIER SCIENCE BV 268 (1-2) 102 - 107 0022-510X 2008/05 [Refereed]
   

  In order to determine whether functional neuroimaging studies can predict the prognosis of hemianopia due to organic cerebral disorders, we studied 8 patients (6 men and 2 women; age, 56.0 +/- 8.6 years) with homonymous hemianopia and compared them with 15 normal subjects (6 men and 9 women; age, 54.3 +/- 4.4 years). The cerebral glucose metabolism and C-11-flumazenil (FMZ) binding were measured by positron emission tomography, more than I month after the onset of the condition. Bilateral regions of interest (ROIs) were selected in the striate cortex, extrastriate cortex, cuneus and thalamus. Further, semi-quantitative data on the cerebral glucose metabolism and FMZ binding were obtained for the ROIs and compared with the data obtained for homologous regions in the contralateral hemisphere by calculating the ipsilateral/ contralateral (I/C) ratio. The I/C ratios for the cerebral glucose metabolism and FMZ binding in the striate cortex were significantly low in the patients (glucose metabolism, P<0.0005; FMZ binding, P<0.005), while the ratio for the FMZ binding in the cuneus increased (P<0.0005). We observed that 5 patients, whose I/C ratio for the FMZ binding in the striate cortex was >0.850, experienced an improvement in their visual field, while that 3 patients with lower PC ratios did not. The FMZ-PET may be useful to predict the prognosis of hemianopia in the chronic phase. (C) 2007 Elsevier B.V. All rights reserved.
• Low density of sigma(1) receptors in early Alzheimer's disease

  Masahiro Mishina; Masashi Ohyama; Kenji Ishii; Shin Kitamura; Yuichi Kimura; Kei-ichi Oda; Kazunori Kawamura; Toru Sasaki; Shiro Kobayashi; Yasuo Katayama; Kiichi Ishiwata

  ANNALS OF NUCLEAR MEDICINE SPRINGER 22 (3) 151 - 156 0914-7187 2008/04 [Refereed]
   

  Objective The sigma, receptor is considered to be involved in cognitive function. A postmortem study reported that the sigma, receptors were reduced in the hippocampus in Alzheimer's disease (AD). However, in vivo imaging of sigma, receptors in the brain of AD patients has not been reported. The aim of this study is to investigate the mapping of sigma, receptors in AD using [(11)C]SA4503 positron emission tomography (PET). Methods We studied five AD patients and, seven elderly volunteers. A dynamic series of decay-corrected PET data acquisition was performed for 90 min starting at the time of the injection of 500 MBq of [(11)C]SA4503. A two-tissue three-compartment model was used to estimate K(1), k(2), k(3), k(4), and the delay between metabolite-corrected plasma and tissue time activity using a Gauss-Newton algorithm. The ratio of k(3) to k(4) was computed as the binding potential (BP), which is linearly related to the density of sigma, receptors. Unpaired t tests were used to compare K(1) and BP in patients with AD and normal subjects. Results As compared with normals, BP in the AD was significantly lower in the frontal, temporal, and occipital lobe, cerebellum and thalamus, whereas K(1) was significantly lower in the parietal lobe. Conclusions [(11)C]SA4503 PET can demonstrate that the density of cerebral and cerebellar sigma, receptors is reduced in early AD.
• Influence of mild hyperglycemia on cerebral FDG distribution patterns calculated by statistical parametric mapping

  Keiichi Kawasaki; Kenji Ishii; Yoko Saito; Keiichi Oda; Yuichi Kimura; Kiichi Ishiwata

  ANNALS OF NUCLEAR MEDICINE SPRINGER 22 (3) 191 - 200 0914-7187 2008/04 [Refereed]
   

  Objective In clinical cerebral 2-[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) studies, we sometimes encounter hyperglycemic patients with diabetes mellitus or patients who have not adhered to the fasting requirement. The objective of this study was to investigate the influence of mild hyperglycemia (plasma glucose range 110-160 mg/dl) on the cerebral FDG distribution patterns calculated by statistical parametric mapping (SPM). Methods We studied 19 healthy subjects (mean age 66.2 years). First, all the subjects underwent FDG-PET scans in the fasting condition. Then, 9 of the 19 subjects (mean age 64.3 years) underwent the second FDG-PET scans in the mild hyperglycemic condition. The alterations in the FDG-PET scans were investigated using SPM- and region of interest (ROT)-based analyses. We used three reference regions: (1) SPM global brain (SPMgb) used for SPM global mean calculation, (2) the gray and white matter region computed from magnetic resonance image (MRIgw), and (3) the cerebellar cortex (Cbll). Results The FDG uptake calculated as the standardized uptake value (average) in SPMgb, MRIgw, and Cbll regions in the mild hyperglycemic condition was 42.7%, 41.3%, and 40.0%, respectively, of that observed in the fasting condition. In SPM analysis, the mild hyperglycemia was found to affect the cerebral distribution patterns of FDG. The FDG uptake was relatively decreased in the gray matter, mainly in the frontal, temporal, and parietal association cortices, posterior cingulate, and precuneus in both SPMgb- and MRIgw-reference-based analyses. When Cbll was adopted as the reference region, those decrease patterns disappeared. The FDG uptake was relatively increased in the white matter, mainly in the centrum semiovale in all the reference-based analyses. Conclusions It is noteworthy that the FDG distribution patterns were altered under mild hyperglycemia in SPM analysis. The decreased uptake patterns in SPMgb(SPM default) and MRIgw-reference-based analyses resembled those observed in Alzheimer's disease. Under mild hyperglycemia, we can recommend Cbll as the reference region to detect decreased uptake patterns. We should pay special attention to controlling the diet condition, monitoring hyperglycemia, and optimizing the reference region in SPM analysis, particularly in the diagnosis of early Alzheimer's disease in clinical FDG-PET.
• Robust estimation of the arterial input function for Logan plots using an intersectional searching algorithm and clustering in positron emission tomography for neuroreceptor imaging

  Mika Naganawa; Yuichi Kimura; Junichi Yano; Masahiro Mishina; Masao Yanagisawa; Kenji Ishii; Kelichi Oda; Klichi Ishiwata

  NEUROIMAGE ACADEMIC PRESS INC ELSEVIER SCIENCE 40 (1) 26 - 34 1053-8119 2008/03 [Refereed]
   

  The Logan plot is a powerful algorithm used to generate binding-potential images from dynamic positron emission tomography (PET) images in neuroreceptor studies. However, it requires arterial blood sampling and metabolite correction to provide an input function, and clinically it is preferable that this need for arterial blood sampling be obviated. Estimation of the input function with metabolite correction using an intersectional searching algorithm (ISA) has been proposed. The ISA seeks the input function from the intersection between the planes spanned by measured radioactivity curves in tissue and their cumulative integrals in data space. However, the ISA is sensitive to noise included in measured curves, and it often fails to estimate the input function. In this paper, we propose a robust estimation of the cumulative integral of the plasma time-activity curve (pTAC) using ISA (robust EPISA) to overcome noise issues. The EPISA reduces noise in the measured PET data using averaging and clustering that gathers radioactivity curves with similar kinetic parameters. We confirmed that a little noise made the estimation of the input function extremely difficult in the simulation. The robust EPISA was validated by application to eight real dynamic [(11)C]TMSX PET data sets used to visualize adenosine A(2A) receptors and four real dynamic [(11)C]PIB PET data sets used to visualize amyloid-beta plaque. Peripherally, the latter showed faster metabolism than the former. The clustering operation improved the signal-to-noise ratio for the PET data sufficiently to estimate the input function, and the calculated neuroreceptor images had a quality equivalent to that using measured pTACs after metabolite correction. Our proposed method noninvasively yields an alternative input function for Logan plots, allowing the Logan plot to be more useful in neuroreceptor studies. (c) 2007 Elsevier Inc. All rights reserved.
• Wavelet denoising for voxel-based compartmental analysis of peripheral benzodiazepine receptors with F-18-FEDAA1106

  Miho Shidahara; Yoko Ikoma; Chie Seki; Yota Fujimura; Mika Naganawa; Hiroshi Ito; Tetsuya Suhara; Iwao Kanno; Yuichi Kimura

  EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING SPRINGER 35 (2) 416 - 423 1619-7070 2008/02 [Refereed]
   

  Purpose We evaluated the noise reduction capability of wavelet denoising for estimated binding potential (BP) images (k(3)/k (4)) of the peripheral benzodiazepine receptor using F-18-FEDAA1106 and nonlinear least-square fitting. Methods Wavelet denoising within a three-dimensional discrete dual-tree complex wavelet transform was applied to simulate data and clinical dynamic positron emission tomography images of F-18-FEDAA1106. To eliminate noise components in wavelet coefficients, real and imaginary coefficients for each subband were thresholded individually using NormalShrink. A simulated dynamic brain image of F-18-FEDAA1106 was generated and Gaussian noise was added to mimic PET dynamic scan. The derived BP images were compared with true images using 156 rectangular regions of interest. Wavelet denoising was also applied to data derived from seven young normal volunteers. Results In the simulations, estimated BP by denoised image showed better correlation with the true BP values (Y=0.83X+0.94, r=0.80), although no correlation was observed in the estimates between noise-added and true images (Y=1.2X+0.78, r=0.49). For clinical data, there were visual improvements in the signal-to-noise ratio for estimated BP images. Conclusions Wavelet denoising improved the bias and reduced the variation of pharmacokinetic parameters for BP.
• Shortened protocol in practical [(11)C]SA4503-PET studies for sigma(1) receptor quantification

  Muneyuki Sakata; Yuichi Kimura; Mika Naganawa; Masatomo Ishikawa; Keiichi Oda; Kenji Ishii; Kenji Hashimoto; Kunihiro Chihara; Kiichi Ishiwata

  ANNALS OF NUCLEAR MEDICINE SPRINGER 22 (2) 143 - 146 0914-7187 2008/02 [Refereed]
   

  In practical positron emission tomography (PET) diagnosis, a shortened protocol is preferred for patients with brain disorders. In this study, the applicability of a shortened protocol as an alternative to the 90-min PET scan with [(11)C]SA4503 for quantitative sigma(1) receptor measurement was investigated. Tissue time-activity curves of 288 regions of interest in the brain from 32 [(11)C]SA4503-PET scans of 16 healthy subjects prior to and following administration of a selective serotonin reuptake inhibitor (fluvoxamine or paroxetine) were applied to two algorithms of quantitative analysis; binding potential (BP) was derived from compartmental analysis based on nonlinear estimation, and total distribution volume (tDV) was derived from Logan plot analysis. As a result, although both BP and tDV tended to be underestimated by the shortened method, the estimates from the shortened protocol had good linear relationships with those of the full-length protocol. In conclusion, if approximately 10% differences in the estimated results are acceptable for a specific purpose, then a 60-min measurement protocol is capable of providing reliable results.
• Evaluation of k(2) imaging algorithm with C-11-verapamil using clustering-based kinetic approach

  Yuichi Kimura; M. Naganawa; K. Oda; K. Ishii; I. Leir; K. Ishiwata

  NEUROIMAGE ACADEMIC PRESS INC ELSEVIER SCIENCE 41 T68 - T68 1053-8119 2008 [Refereed]
  
• Presynaptic and postsynaptic nigrostriatal dopaminergic functions in multiple system atrophy

  Masaya Hashimoto; Keiichi Kawasaki; Masahiko Suzuki; Kazuko Mitania; Shigeo Murayama; Masahiro Mishina; Keiichi Oda; Yuichi Kimura; Kiichi Ishiwata; Kenji Ishiia; Kiyoharu Inoue

  NEUROREPORT LIPPINCOTT WILLIAMS & WILKINS 19 (2) 145 - 150 0959-4965 2008/01 [Refereed]
   

  A simultaneous evaluation of presynaptic and postsynaptic dopaminergic positron emission tomography markers, the dopamine transporters and the dopamine D-2-like receptors, was performed in eight patients with parkinsonian phenotype of multiple system atrophy. Both presynaptic and postsynaptic markers were revealed to have declined in such a manner that they kept strong positive correlation throughout the striatum of all patients, suggesting that the degeneration process in the striatum may involve the entire structure of the dopaminergic synapse. In two L-3,4,dihydroxyphenyl-alanine-responsive cases, the balance of decline in two markers was relatively shifted to presynaptic dominant side. Correlative positron emission tomography study of presynaptic and postsynaptic dopaminergic function may be useful for the diagnosis of multiple system atrophy and to understand the mechanisms of its temporal L-3,4,dihydroxyphenyl-alanine responsiveness.
• Distribution volume as an alternative to the binding potential for sigma(1) receptor imaging

  Yuichi Kimura; Mika Naganawa; Muneyuki Sakata; Masatomo Ishikawa; Masahiro Mishina; Keiichi Oda; Kenji Ishii; Kiichi Ishiwata

  ANNALS OF NUCLEAR MEDICINE SPRINGER 21 (9) 533 - 535 0914-7187 2007/11 [Refereed]
   

  yThe applicability of total distribution volume (DVt) as an alternative to binding potential (BP) was investigated for neuroreceptor mapping by positron emission tomography (PET). BP is defined as a representative quantity of receptor density. However, for making parametric images of BP, a reference region where an aimed receptor has a very low density is assumed to exist in a target region such as the brain. Thus, if the kinetics of a radioligand for target receptors does not permit an appropriate reference region, BP imaging is unattainable. In this study, [C-11]SA4503 PET is taken to be considered which has a high affinity to the sigma(1) receptors. Through a clinical investigation using wide ranges of physiological situations, ages, sex, diseases, and selective drug-loading conditions, DVt has a good linear relationship with BP, and the images can be used as a spatial distribution of sigma(1) density.
• High occupancy of sigma-1 receptors in the human brain after single oral administration of fluvoxamine: A positron emission tomography study using [C-11]SA4503

  Masatomo Ishikawa; Kiichi Ishiwata; Kenji Ishii; Yuichi Kimura; Muneyuki Sakata; Mika Naganawa; Keiichi Oda; Ryousuke Miyatake; Mihisa Fujisaki; Eiji Shimizu; Yukihiko Shirayama; Masaomi Iyo; Kenji Hashimoto

  BIOLOGICAL PSYCHIATRY ELSEVIER SCIENCE INC 62 (8) 878 - 883 0006-3223 2007/10 [Refereed]
   

  Background: Sigma-1 receptors might be implicated in the pathophysiology of psychiatric diseases, as well as in the mechanisms of action of some selective serotonin reuptake inhibitors (SSRIs). Among the several SSRIs, fluvoxamine has the highest affinity for sigma-1 receptors (Ki = 36 nM), whereas paroxetine shows low affinity (Ki = 1893 nM). The present study was undertaken to examine whether fluvoxamine binds to sigma-1 receptors in living human brain. Methods: A dynamic positron emission tomography (PET) data acquisition using the selective sigma-1 receptor ligand [C-11]SA4503 was performed with arterial blood sampling to evaluate quantitatively the binding of [C-11]SA4503 to sigma-1 receptors in 15 healthy male volunteers. Each subject had two PET scans before and after randomly receiving a single dose of either fluvoxa mine (50,100,150, or 200 mg) or paroxetine (20 mg). The binding potential of [C-11]SA4503 in 9 regions of the brain was calculated by a 2-tissue 3-compartment model. In addition, we examined the effects of functional polymorphisms of the sigma-1 receptor (SIGMARI) gene on the binding potential of [C-11]SA4503. Results: Fluvoxamine bound to sigma-1 receptors in all brain regions in a dose-dependent manner, whereas paroxetine did not bind to sigma-1 receptors. However, there was no association between the SIGMAR1 gene polymorphism GC-241-240TT and binding potential. Conclusions: The study demonstrated that fluvoxamine bound to sigma-1 receptors in living human brain at therapeutic doses. These findings suggest that sigma-1 receptors may play an important role in the mechanism of action of fluvoxamine.
• Evaluation of distribution of adenosine A(2A) receptors in normal human brain measured with [(11)C]TMSX PET

  Masahiro Mishina; Kiichi Ishiwata; Yuichi Kimura; Mika Naganawa; Keiichi Oda; Shiro Kobayashi; Yasuo Katayama; Kenji Ishii

  SYNAPSE WILEY-BLACKWELL 61 (9) 778 - 784 0887-4476 2007/09 [Refereed]
   

  Adenosine A(2A) receptor (A2AR) is thought to interact with dopamine D(2) receptor. Selective A2AR antagonists have attracted attention as the treatment of Parkinson's disease. In this study, we investigated the distribution of the A2ARs in the living human brain using positron emission tomography (PET) and [7-methyl-(11)C]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine ([(11)C]TMSX). We recruited five normal male subjects. A dynamic series of PET scans was performed for 60 min, and the arterial blood was sampled during the scan to measure radioactivity of the parent compound and labeled metabolites. Circular regions of interest of 10-mm diameter were placed in the PET images over the cerebellum, brainstem, thalamus, head of caudate nucleus, anterior and posterior putamen, frontal lobe, temporal lobe, parietal lobe, occipital lobe, and posterior cingulate gyrus for each subject. A two-tissue, three-compartment model was used to estimate K(1), k(2), k(3), and k(4) between metabolite-corrected plasma and tissue time activity of [(11)C]TMSX. The binding potential (BP) was the largest in the anterior (1.25) and posterior putamen (1.20), was next largest in the head of caudate nucleus (1.05) and thalamus (1.03), and was small in the cerebral cortex, especially frontal lobe (0.46). [(11)C]TMSX PET showed the largest BP in the striatum in which A2ARs were enriched as in postmortem and nonhuman studies reported, but that the binding of [(11)C]TMSX was relatively larger in the thalamus to compare with other mammals. To date, [(11)C]TMSX is the only promising PET ligand, which is available to clinical use for mapping the A2ARs in the living human brain. (c) 2007 Wiley-Liss, Inc.
• Temporal and spatial blood information estimation using Bayesian ICA in dynamic cerebral positron emission tomography

  Mika Naganawa; Yuichi Kimura; Kenji Ishii; Keiichi Oda; Kiichi Ishiwata

  DIGITAL SIGNAL PROCESSING ACADEMIC PRESS INC ELSEVIER SCIENCE 17 (5) 979 - 993 1051-2004 2007/09 [Refereed]
   

  Positron emission tomography (PET) is a nuclear medicine technique that provides tomographic images of the distribution of positron-emitting radiopharmaceuticals. We have previously proposed a method for estimating an input blood curve based on a standard independent component analysis using a specially designed cost function and a preprocessing scheme. While the input blood curve was successfully extracted, the voxels with a negative sign remained in the estimated blood volume image. They should be positive because of its physiological meaning. In this study, ensemble learning introduces a nonnegative constraint to correctly estimate temporal and spatial blood information from dynamic cerebral PET images. The rectified Gaussian distribution and exponential distribution were adopted as nonnegative priors on the elements of the time curves and the source images, respectively. The proposed method (extraction of the plasma time-activity curve using ensemble learning, EPEL) was applied to human brain PET studies with three kinds of radiopharmaceuticals for investigating its validity. The results implied that the EPEL-estimated blood curve was similar to the measured curve, and that the estimated blood volume correlated well with that measured clinically. We concluded that EPEL is a valid method for estimating the blood curve and the blood volume image in a noninvasive way. (C) 2007 Elsevier Inc. All rights reserved.
• The use of positron emission tomography and [F-18] fluorodeoxyglucose for functional imaging of muscular activity during exercise with a stride assistance system

  Hiroyuki Shimada; Yuichi Kimura; Takao Suzuki; Takashi Hirata; Miho Sugiura; Yosuke Endo; Ken Yasuhara; Kei Shimada; Keishiro Kikuchi; Masaya Hashimoto; Masatomo Ishikawa; Keiichi Oda; Kenji Ishii; Kiichi Ishiwata

  IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC 15 (3) 442 - 448 1534-4320 2007/09 [Refereed]
   

  The aim of this study was to investigate the use of [F-18] fluorodeoxyglucose and positron emission tomography(FDG PET) for quantitative evaluation of glucose metabolism in skeletal muscle during walking. Ten young males underwent FDG PET twice during walks, which were done with or without an automated stride assistance system (SAS). Walk ratios were significantly increased by the SAS in seven subjects. Regional glucose metabolism in muscles between the crista iliaca: and the planta was clearly visualized in all ten subjects. Glucose utilization increased significantly in the tibialis posterior and medial gastrocnemius muscles of the seven subjects in whom walk ratios were increased by the SAS. FDG PET is useful for analysis of muscle activity during exercise and rehabilitation.
• Synthesis and evaluation of fluorine-18-labeled SA4503 as a selective sigma(1) receptor ligand for positron emission tomography

  Kazunori Kawamura; Hideo Tsukada; Kazuhiro Shiba; Chieko Tsuji; Norihiro Harada; Yuichi Kimura; Klichi Ishlwata

  NUCLEAR MEDICINE AND BIOLOGY ELSEVIER SCIENCE INC 34 (5) 571 - 577 0969-8051 2007/07 [Refereed]
   

  The [F-18]fluoromethyl analog of the sigma, selective ligand 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride (SA4503) ([F-18]FM-SA4503) was prepared and its potential evaluated for the in vivo measurement of sigma, receptors with positron emission tomography (PET). FM-SA4503 had selective affinity for the sigma, receptor (K-i for sigma, receptor, 6.4 nM; Ki for sigma(2) receptor, 250 nM) that was compatible with the affinity of SA4503 (K-i for sigma, receptor, 4.4 nM; Ki for sigma2 receptor, 242 nM). [F-18]FM-SA4503 was synthesized by F-18-fluoromethylation of O-demethyl SA4503 in the radiochemical yield of 2.9-16.6% at the end of bombardment with a specific activity of 37.8-283 TBq/mmol at the end of synthesis. In mice, the uptake of [F-18]FM-SA4503 in the brain was gradually increased for 30 min after injection, and then decreased. In the blocking study, brain uptake was significantly decreased by coinjection of haloperidol to 32% of control, and FM-SA4503 to 52% of control. In PET study of the monkey brain, high uptake was found in the cerebral cortex, thalamus and striatum. The radioactivity level of [F-18]FM-SA4503 in the brain regions gradually increased over a period of 120 min after injection, followed by a stable plateau phase until 180 min after injection. In pretreatment with haloperidol measurement of the monkey brain, the radioactivity level was 22-32% and 11-25% of the baseline at 60 and 180 min, respectively, after injection, suggesting high receptor-specific binding. [F-18]FM-SA4503 showed specific binding to sigma, receptors in mice and monkeys;, therefore, [F-18]FMSA4503 has the potential for mapping sigma, receptors in the brain. (c) 2007 Elsevier Inc. All rights reserved.
• Quantification of adenosine A(2A) receptors in the human brain using [C-11]TMSX and positron emission tomography

  Mika Naganawa; Yuichi Kimura; Masahiro Mishina; Yoshitsugu Manabe; Kunihiro Chihara; Keiichi Oda; Kenji Ishii; Kiichi Ishiwata

  EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING SPRINGER 34 (5) 679 - 687 1619-7070 2007/05 [Refereed]
   

  Purpose [7-methyl-C-11]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine ([C-11]TMSX) is a positron-emitting adenosine A(2A) receptor (A2AR) antagonist for visualisation of A2AR distribution by positron emission tomography (PET). The aims of this paper were to use a kinetic model to analyse the behaviour of [C-11]TMSX in the brain and to examine the applicability of the Logan plot. We also studied the applicability of a simplified Logan plot by omitting metabolite correction and arterial blood sampling. Methods The centrum semiovale was used as a reference region on the basis of a post-mortem study showing that it has a negligibly low density of A2ARs. Compartmental analysis was performed in five normal subjects. Parametric images of A2AR binding potential (BP) were also generated using a Logan plot with or without metabolite correction and with or without arterial blood sampling. To omit arterial blood sampling, we applied a method to extract the plasma-related information using independent component analysis (EPICA). Results The estimated K-1/k(2) was confirmed to be common in the centrum semiovale and main cortices. The three-compartment model was well fitted to the other regions using the fixed value of K-1/k(2) estimated from the centrum semiovale. The estimated BPs using the Logan plot matched those derived from compartment analysis. Without the metabolite correction, the estimate of BP underestimated the true value by 5%. The estimated BPs agreed regardless of arterial blood sampling. Conclusion A three-compartment model with a reference region, the centrum semiovale, describes the kinetic behaviour of [C-11]TMSX PET images. A2ARs in the human brain can be visualised as a BP image using [C-11]TMSX PET without arterial blood sampling.
• Mapping of human cerebral sigma, receptors using positron emission tomography and [C-11]SA4503

  Muneyuki Sakata; Yuichi Kimura; Mika Naganawa; Kelichi Oda; Kenji Ishii; Kunihiro Chihara; Kiichi Ishiwata

  NEUROIMAGE ACADEMIC PRESS INC ELSEVIER SCIENCE 35 (1) 1 - 8 1053-8119 2007/03 [Refereed]
   

  The objective of this study was to establish the kinetic analysis for mapping sigma, receptors (cFIRs) in the human brain by positron emission tomography (PET) with [C-11]SA4503. The crlRs are considered to be involved in various neurological and psychiatric diseases. [C-11]SA4503 is a recently developed radioligand with high and selective affinity for cFIRs, and we have first applied it to clinical studies. Nine healthy male subjects each underwent a dynamic 90-min PET scan after injection of [C-11]SA4503. In addition to the baseline measurement, three of the nine subjects underwent a second [C-11] SA4503-PET after partial blockade of sigma IRs by oral administration of haloperidol, a sigma receptor antagonist. Full kinetic analysis using two times nonlinear estimations was applied for fitting a two-tissue three-compartment model to determine the binding potential (BP) and total distribution volume (tDV) of [C-11]SA4503. Graphical analysis with a Logan plot was also applied for estimations of tDV. The regional distribution patterns of BP and tDV in 11 regions were compatible with those of previously reported crlRs in vitro. The reduced binding sites of sigma IRs by haloperidol were appropriately evaluated. The tDVs derived from the two methods matched each other well. The Logan plot offered images of the tDV, which reflected sigma 1R densities, and the tDV in the images decreased after haloperidol loading. Moreover, comparison of BPs calculated with and without metabolite correction for plasma input function indicated that the metabolite correction could be omitted. We concluded that this method enables the quantitative analysis of sigma 1Rs in the human brain. (c) 2006 Elsevier Inc. All rights reserved.
• Inter-crystal scatter identification for a depth-sensitive detector using support vector machine for small animal positron emission tomography

  Eiji Yoshida; Kelshi Kitamura; Yuichi Kimura; Fumihiko Nishikido; Kengo Shibuya; Taiga Yamaya; Hideo Murayama

  NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT ELSEVIER SCIENCE BV 571 (1-2) 243 - 246 0168-9002 2007/02 [Refereed]
   

  In a conventional positron emission tomography (PET) detector, detected events are projected onto a 2D position histogram by an Anger calculation for crystal identification. However, the measured histogram is affected by inter-crystal scatterings (ICS) which occur in the entire detector. Peaks which are projected for each crystal in the histogram are blurred, and this causes ICS mispositioning. A depth-of-interaction (DOI) detector has been developed for the small animal PET scanner jPET-RD. This DOI detector uses 32 x 32 crystals with four layers and a 256-channel multi-anode flat panel photomultiplier tube (FP-PMT) which was developed by Hamamatsu Photonics K.K. Each crystal element is 1.45 x 1.45 x 4.5 mm(3). The FP-PMT has a large detective area (49 x 49 mm(2)) and a small anode pitch (3.04 mm). Therefore, the FP-PMT can extensively trace the behavior of incident gamma rays in the crystals including ICS event. We, therefore, propose a novel method for ICS estimation using a statistical pattern recognition algorithm based on a support vector machine (SVM). In this study, we applied the SVM for discriminating photoelectric events from ICS events generated from multiple-anode outputs. The SVM was trained by uniform irradiation events generated from a detector simulator using a Monte Carlo calculation. The success rate for ICS event identification is about 78% for non-training data. The SVM can achieve a true subtraction of ICS events from measured events. and it is also useful for random correction in PET. (c) 2006 Elsevier B.V. All rights reserved.
• Quantification of regional cerebral blood flow using H_2^<15>O and PET : Improvement of accuracy in the measurement of arterial input function using β-ray probe system

  SEKI C.; OKADA H.; TSUKADA H.; YAMASHITA T.; KIMURA Y.; KANNO I.

  Ionizing radiation. 応用物理学会放射線分科会 33 (1) 37 - 45 0285-3604 2007 [Refereed]
  
• A feasibility study of [C-11]SA4503-PET for evaluating sigma(1) receptor occupancy by neuroleptics: the binding of haloperidol to sigma(1) and dopamine D-2-like receptors

  Kiichi Ishiwata; Kenji Oda; Muneyuki Sakata; Yuichi Kimura; Kazunori Kawamura; Keiichi Oda; Toru Sasaki; Mika Naganawa; Kunihiro Chihara; Yoshiro Okubo; Kenji Ishii

  ANNALS OF NUCLEAR MEDICINE JAPANESE SOCIETY NUCLEAR MEDICINE 20 (8) 569 - 573 0914-7187 2006/10 [Refereed]
   

  We investigated feasibility of positron emission tomography (PET) with [C-11]SA4503 for evaluating the sigma(1) receptor occupancy rate by neuroleptics. Haloperidol, which is well known to bind dopamine D-2-like receptor (D2R) as well as to be a representative non-selective antagonist for sigma I receptor (at R), was selected as a model drug. Three healthy male subjects underwent 60-min [C-11]raclopride-PET and 90-min [C-11]SA4503-PET scans successively at a 120-min interval twice in a day for baseline measurement and on another day for haloperidol-loading measurement 16 hours after peroral administration of 3 mg of halopefidol. Binding potential (BP) of [C-11]raclopfide and [C-11]SA4503 was quantitatively evaluated and the sigma 1R and D2R occupancy rates were determined. D2R occupancy rates by haloperidol were 64% and 62% in the caudate and putamen, respectively, 16 h after the administration, while at R occupancy rates were approximately 80% in all seven regions investigated including the caudate, putamen and cerebellum 18 h after the administration, suggesting that the at R receptor occupancy rate by haloperidol was slightly larger than the D2R receptor occupancy rate. We concluded that [C-11]SA4503-PET can be used for evaluating the sigma lR occupancy rates by neuroleptics or other drugs.
• MAP-based kinetic analysis for voxel-by-voxel compartment model estimation: Detailed imaging of the cerebral glucose metabolism using FDG

  Y Kimura; M Naganawa; J Yamaguchi; Y Takabayashi; A Uchiyama; K Oda; K Ishii; K Ishiwata

  NEUROIMAGE ACADEMIC PRESS INC ELSEVIER SCIENCE 29 (4) 1203 - 1211 1053-8119 2006/02 [Refereed]
   

  We propose a novel algorithm for voxel-by-voxel compartment model analysis based on a maximum a posteriori (MAP) algorithm. Voxel-by-voxel compartment model analysis can derive functional images of living tissues, but it suffers from high noise statistics in voxel-based PET data and extended calculation times. We initially set up a feature space of the target radiopharmaceutical composed of a measured plasma time activity curve and a set of compartment model parameters, and measured the noise distribution of the PET data. The dynamic PET data were projected onto the feature space, and then clustered using the Mahalanobis distance. Our method was validated using simulation studies, and compared with ROI-based ordinary kinetic analysis for FDG. The parametric images exhibited an acceptable linear relation with the simulations and the ROI-based results, and the calculation time took about 10 min. We therefore concluded that our proposed MAP-based algorithm is practical. (c) 2005 Elsevier Inc. All rights reserved.
• 加齢傾向検討のためのガウス混合モデルによる脳PET画像の自動セグメンテーション

  増田泰; 木村裕一; 長縄美香; 千原國宏; 大城理

  医用電子と生体工学 44 (1) 207 - 212 2006 [Refereed]
  
• Brain histamine H-1 receptor occupancy of orally administered antihistamines measured by positron emission tomography with C-11-doxepin in a placebo-controlled crossover study design in healthy subjects: a comparison of olopatadine and ketotifen

  M Tashiro; H Mochizuki; Y Sakurada; K Ishii; K Oda; Y Kimura; T Sasaki; K Ishiwata; K Yanai

  BRITISH JOURNAL OF CLINICAL PHARMACOLOGY BLACKWELL PUBLISHING 61 (1) 16 - 26 0306-5251 2006/01 [Refereed]
   

  Aims The strength of sedation due to antihistamines can be evaluated by using positron emission tomography (PET). The purpose of the present study is to measure histamine H-1 receptor (H1R) occupancy due to olopatadine, a new second-generation antihistamine and to compare it with that of ketotifen. Methods Eight healthy males (mean age 23.5 years-old) were studied following single oral administration of olopatadine 5 mg or ketotifen 1 mg using PET with C-11-doxepin in a placebo-controlled crossover study design. Binding potential ratio and H1R occupancy were calculated and were compared between olopatadine and ketotifen in the medial prefrontal (MPFC), dorsolateral prefrontal (DLPFC), anterior cingulate (ACC), insular (IC), temporal (TC), parietal (PC), occipital cortices (OC). Plasma drug concentration was measured, and correlation of AUC to H1R occupancy was examined. Results H1R occupancy after olopatadine treatment was significantly lower than that after ketotifen treatment in the all cortical regions (P < 0.001). Mean H1R occupancies for olopatadine and ketotifen were, respectively: MPFC, 16.7 vs. 77.7; DLPFC, 14.1 vs. 85.9; ACC, 14.7 vs. 76.1; IC, 12.8 vs. 69.7; TC, 12.5 vs. 66.5; PC, 13.9 vs. 65.8; and OC, 19.5 vs. 60.6. Overall cortical mean H1R occupancy of olopatadine and ketotifen were 15% and 72%, respectively. H1R occupancy of both drugs correlated well with their respective drug plasma concentrations (P < 0.001). Conclusion It is suggested that 5 mg oral olopatadine, with its low H1R occupancy and thus minimal sedation, could safely be used an antiallergic treatment for various allergic disorders.
• Greater adenosine A(2A) receptor densities in cardiac and skeletal muscle in endurance-trained men: a [C-11]TMSX PET study

  M Mizuno; Y Kimura; K Tokizawa; K Ishii; K Oda; T Sasaki; Y Nakamura; Muraoka, I; K Ishiwata

  NUCLEAR MEDICINE AND BIOLOGY ELSEVIER SCIENCE INC 32 (8) 831 - 836 0969-8051 2005/11 [Refereed]
   

  We examined the densities of adenosine A(2A) receptors in cardiac and skeletal muscles between untrained and endurance-trained subjects using positron emission tomography (PET) and [7-methyl-C-11]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine ([C-11]TMSX), a newly developed radioligand for mapping adenosine A(2A) receptors. Five untrained and five endurance-trained subjects participated in this study. The density of adenosine A(2A) receptors was evaluated as the distribution volume of [C-11]TMSX in cardiac and triceps brachii muscles in the resting state using PET. The distribution volume of [C-11]TMSX in the myocardium was significantly greater than in the triceps brachii muscle in both groups. Further, distribution volumes [C-11]TMSX in the trained subjects were significantly grater than those in untrained subjects (myocardium, 3.6 +/- 0.3 vs. 3.1 +/- 0.4 ml g(-1); triceps brachii muscle, 1.7 +/- 0.3 vs. 1.2 +/- 0.2 ml g(-1), respectively). These results indicate that the densities of adenosine A(2A) receptors in the cardiac and skeletal muscles are greater in the endurance-trained men than in the untrained men. (c) 2005 Elsevier Inc. All rights reserved.
• Use of reference tissue models for quantification of histamine H-1 receptors in human brain by using positron emission tomography and [C-11]doxepin

  A Suzuki; M Tashiro; Y Kimura; H Mochizuki; K Ishii; H Watabe; K Yanai; K Ishiwata; K Ishii

  ANNALS OF NUCLEAR MEDICINE SPRINGER 19 (6) 425 - 433 0914-7187 2005/09 [Refereed]
   

  The aim of the present study is to evaluate the validity of the simplified reference tissue model (SRTM) and of Logan graphical analysis with reference tissue (LGAR) for quantification of histamine H-1 receptors (H1Rs) by using positron emission tomography (PET) with [C-11]doxepin. These model-based analytic methods (SRTM and LGAR) are compared to Logan graphical analysis (LGA) and to the one-tissue model (1TM), using complete datasets obtained from 5 healthy volunteers. Since H1R concentration in the cerebellum can be regarded as negligibly small, the cerebellum was selected as the reference tissue in the present study. The comparison of binding potential (BP) values estimated by LGAR and 1TM showed good agreement; on the other hand, SRTM turned out to be unstable concerning parameter estimation in several regions of the brain. By including the results of noise analysis, LGAR became a reliable method for parameter estimation of [C-11]doxepin data in the cortical regions.
• Function of sigma(1) receptors in Parkinson's disease

  M Mishina; K Ishiwata; K Ishii; S Kitamura; Y Kimura; K Kawamura; K Oda; T Sasaki; O Sakayori; M Hamamoto; S Kobayashi; Y Katayama

  ACTA NEUROLOGICA SCANDINAVICA BLACKWELL PUBLISHING 112 (2) 103 - 107 0001-6314 2005/08 [Refereed]
   

  Objective - The objective of this study was to investigate the mapping of sigma(1) receptors in Parkinson's disease (PD) using [C-11]SA4503 and positron emission tomography (PET), and to assess whether sigma1 receptors are involved in the damaged dopaminergic system in PD patients. Materials and methods - We studied seven normal volunteers and six PD patients. The low density of dopamine transporters and the normal or high density of dopamine receptors were confirmed in the putamen of all patients using [C-11]CFT and [C-11] RAC PET. A dynamic series of PET data acquisition was performed with arterial blood sampling. We computed the binding potential (BP) of [C-11]SA4503. Results - In PD patients, the BP was significantly lower on the more affected than the less affected side of the anterior putamen, although there was no significant difference with respect to the BP between patients and controls. Conclusions - Release of dopamine is reduced asymmetrically in the putamen of early PD. [C-11]SA4503 PET is an indicator of presynaptic dopaminergic damage in PD.
• Omission of serial arterial blood sampling in neuroreceptor imaging with independent component analysis

  M Naganawa; Y Kimura; T Nariai; K Ishii; K Oda; Y Manabe; K Chihara; K Ishiwata

  NEUROIMAGE ACADEMIC PRESS INC ELSEVIER SCIENCE 26 (3) 885 - 890 1053-8119 2005/07 [Refereed]
   

  We have previously proposed a statistical method for extracting a plasma time-activity curve (pTAC) from dynamic PET images, named EPICA, for kinetic analysis of cerebral glucose metabolism. We assumed that the dynamic PET images consist of a blood-related component and a tissue-related component which are spatially independent in a statistical sense. The aim of this study is to investigate the utility of EPICA in imaging total distribution volume (DVt) and binding potential (BP) with Logan plots in a neuroreceptor mapping study. We applied EPICA to dynamic [C-11]MPDX PET images in 25 subjects, including healthy subjects and patients with brain diseases, and validated the estimated pTACs. [C-11]MPDX is a newly developed radiopharmaceutical for mapping cerebral adenosine A, receptors. EPICA successfully extracted pTAC for all 25 subjects. Parametric images of DVts were estimated by applying Logan plots with the EPICA-estimated pTAC and then used to define a reference region. The BPs estimated using EPICA were evaluated in 18 subjects by ROI-based comparison with those obtained using the nonlinear least squares method (NLSM). The calculated BPs were identical to the estimates using NLSM in each subject. We conclude that EPICA is a promising technique that generates parametric images of DVt and BP in neuroreceptor mapping without requiring arterial blood sampling. (c) 2005 Elsevier Inc. All rights reserved.
• Preclinical and clinical evaluation of O-[C-11]methyl-L-tyrosine for tumor imaging by positron emission tomography

  K Ishiwata; H Tsukada; K Kubota; T Nariai; N Harada; K Kawamura; Y Kimura; K Oda; R Iwata; K Ishii

  NUCLEAR MEDICINE AND BIOLOGY ELSEVIER SCIENCE INC 32 (3) 253 - 262 0969-8051 2005/04 [Refereed]
   

  We performed preclinical and clinical studies of O-[C-11]methyl-L-tyrosine, a potential tracer for imaging amino acid transport Of tumors by positron emission tomography (PET). Examinations of the radiation-absorbed dose by O-[C-11]methyl-L-tyrosine and the acute toxicity and mutagenicity of O-methyl-L-tyrosine showed suitability of the tracer for clinical use. The whole-body imaging of monkeys and healthy humans by PET showed low uptake of O-[C-11]methyl-L-tyrosine in all normal organs except for the urinary track and bladder, suggesting that the O-[C-11]methyl-L-tyrosine PET has the potential for tumor imaging in the whole-body. Finally, the brain tumor imaging was preliminarily demonstrated. (c) 2005 Elsevier Inc. All rights reserved.
• First visualization of adenosine A(2A) receptors in the human brain by positron emission tomography with [C-11]TMSX

  K Ishiwata; M Mishina; Y Kimura; K Oda; T Sasaki; K Ishii

  SYNAPSE WILEY-LISS 55 (2) 133 - 136 0887-4476 2005/02 [Refereed]
   

  [C-11]TMSX is a new positron emission tomography (PET) radioligand that provides visualization of adenosine A(2A) receptors (A(2A)Rs) in the brain, heart and skeletal muscle. Here we report on the first visualization of the A(2A)Rs in the human brain by PET and [C-11]TMSX in a male healthy volunteer, compared with the adenosine A, receptors (A(1)Rs) and dopamine D-2 receptors (D(2)Rs) which were measured by PET with [C-11]MPDX and [C-11]raclopride, respectively. The distribution volume (DV) of [C-11]TMSX in the baseline was relatively high in the head of caudate nucleus, putamen, and thalamus and relatively low in the cortical regions. Infusion of theophylline, a nonselective A(2A)R antagonist (K for A(2A)Rs = 16000 nM for theophylline vs 5.9 nM for TMSX), slightly reduced the DVs in the head of caudate nucleus (8.0% reduction) and putamen (4.5% reduction), but not in the other regions having much lower levels of A(2A)Rs, demonstrating the A(2A)R-specific binding of [C-11]TMSX. On the other hand, the A(1)Rs were widely distributed in the whole brain except for the cerebellum, while the binding potential of [C-11]raclopride was predominantly high in the striatum. We concluded that [C-11]TMSX is an applicable PET ligand for mapping the A(2A)Rs in the caudate nucleus and putamen in clinical studies because of no availability of other radioligands until now. The [C-11]TMSX PET is of great interest for studying the pathophysiology of neurological and psychiatric disorders together with the [C-11]raclopride PET for D(2)Rs evaluation and/or the [C-11]MPDX PET for A(1)Rs evaluation. (C) 2004 Wiley-Liss, Inc.
• Extraction of a plasma time-activity curve from dynamic brain PET images based on independent component analysis

  M Naganawa; Y Kimura; K Ishii; K Oda; K Ishiwata; A Matani

  IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC 52 (2) 201 - 210 0018-9294 2005/02 [Refereed]
   

  A compartment model has been used for kinetic analysis of dynamic positron emission tomography (PET) data [e.g., 2-deoxy-2-F-18-fluoro-D-glucose (FDG)]. The input function of the model [the plasma time-activity curve (pTAC)] was obtained by serial arterial blood sampling. It is of clinical interest to develop a method for PET studies that estimates the pTAC without needing serial arterial blood sampling. For this purpose, we propose a new method to extract the pTAC from the dynamic brain PET images using a modified independent component analysis [extraction of the pTAC using independent component analysis (EPICA). Source codes of EPICA are freely available at http://www5f.biglobe.ne.jp/-ukimura/Software/top.html]. EPICA performs the appropriate preprocessing and independent component analysis (ICA) using an objective function that takes the various properties of the pTAC into account. After validation of EPICA by computer simulation, EPICA was applied to human brain FDG-PET studies. The results imply that the EPICA-estimated pTAC was similar to the actual measured pTAC, and that the estimated blood volume image was highly correlated with the blood volume image measured using O-15-CO inhalation. These results demonstrated that EPICA is useful for extracting the pTAC from dynamic PET images without the necessity of serial arterial blood sampling.
• Extraction of a plasma time-activity curve from dynamic brain PET images based on independent component analysis

  M Naganawa; Y Kimura; K Ishii; K Oda; K Ishiwata; A Matani

  IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC 52 (2) 201 - 210 0018-9294 2005/02 

  A compartment model has been used for kinetic analysis of dynamic positron emission tomography (PET) data [e.g., 2-deoxy-2-F-18-fluoro-D-glucose (FDG)]. The input function of the model [the plasma time-activity curve (pTAC)] was obtained by serial arterial blood sampling. It is of clinical interest to develop a method for PET studies that estimates the pTAC without needing serial arterial blood sampling. For this purpose, we propose a new method to extract the pTAC from the dynamic brain PET images using a modified independent component analysis [extraction of the pTAC using independent component analysis (EPICA). Source codes of EPICA are freely available at http://www5f.biglobe.ne.jp/-ukimura/Software/top.html]. EPICA performs the appropriate preprocessing and independent component analysis (ICA) using an objective function that takes the various properties of the pTAC into account. After validation of EPICA by computer simulation, EPICA was applied to human brain FDG-PET studies. The results imply that the EPICA-estimated pTAC was similar to the actual measured pTAC, and that the estimated blood volume image was highly correlated with the blood volume image measured using O-15-CO inhalation. These results demonstrated that EPICA is useful for extracting the pTAC from dynamic PET images without the necessity of serial arterial blood sampling.
• Event-by-event random and scatter estimator based on support vector machine using multi-anode outputs

  Eiji Yoshida; Yuichi Kimura; Keishi Kitamura; Fumihiko Nishikido; Taiga Yamaya; Hideo Murayama

  IEEE Nuclear Science Symposium Conference Record 3 1800 - 1803 1095-7863 2005 [Refereed]
   

  In PET, the incident angle of gamma rays is estimated from coincidence information, but coincidence events are contaminated with random and scatter components. The mean contribution to the image from these components can be measured or estimated, but the noise resulting from the statistical variations in the detected events still remains and decreases noise equivalent count rates (NECR). Theoretically, incident angle to detectors or other related information can be used to discriminate random and scatter events from true events for increasing the NECR. This information can be delineated from spatial distributions of deposited energies on multi-anode photomultiplier tubes (PMTs), which arise from inter-crystal scattering and vary with the coincidence event type (true or random/scatter). In this work, a novel method for random and scatter subtraction has been developed using the support vector machine (SVM), a recently developed and widely used statistical pattern recognition scheme. SVM input data are s a pair of spatial distributions of 256 outputs of multi-anode PMTs from coincidence detectors. The SVM is trained by coincidence events generated from a detector simulator using Monte Carlo calculation. True and random coincidence events are simulated and the results show that the proposed method is applicable for event-by-event estimation of random coincidence. © 2005 IEEE.
• Adenosine A(1) receptor mapping of the human brain by PET with 8-dicyclopropylmethyl-1-C-11-methyl-3-propylxanthine

  N Fukumitsu; K Ishii; Y Kimura; K Oda; T Sasaki; Y Mori; K Ishiwata

  JOURNAL OF NUCLEAR MEDICINE SOC NUCLEAR MEDICINE INC 46 (1) 32 - 37 0161-5505 2005/01 [Refereed]
   

  Adenosine is an enclogenous modulator of synaptic functions in the central nervous system. To investigate the physiologic and pathologic roles of the adenosine receptors in the human brain, PET is a powerful in vivo technique. In this study, we quantitatively evaluated the distribution of a major subtype A(1) adenosine receptor in the human brain by PET with a newly developed radioligand, 8-dicyclopropylmethyl-1-C-11-methyl-3-propylxanthine (C-11-MPDX). Methods: In 5 healthy volunteers, after PET measurement of the regional cerebral blood flow (rCBF) with O-15-H2O, a 60-min PET scan with C-11-MPDX was performed. The distribution volume (DV) of C-11-MPDX was quantitatively evaluated by Logan's graphical analysis. Results: C-11-MPDX was taken up at a high level, reaching a peak at 2-2.5 min, followed by a rapid decrease. The unchanged form of C-11-MPDX in plasma was 75% at 60 min after injection. The DV of C-11-MPDX was large in the striaturn and thalamus, moderate in the cerebral cortices and pons, and small in the cerebellum. The distribution pattern of C-11-MPDX in the brain was coincident with that of adenosine A(1) receptors in vitro, reported previously, but discretely different from that of rCBF. Conclusion: C-11-MPDX PET has the potential for mapping adenosine A(1) receptors in the human brain.
• Simplified PET measurement for evaluating histamine H-1 receptors in human brains using [C-11]doxepin

  H Mochizuki; Y Kimura; K Ishii; K Oda; T Sasaki; M Tashiro; K Yanai; K Ishiwata

  NUCLEAR MEDICINE AND BIOLOGY ELSEVIER SCIENCE INC 31 (8) 1005 - 1011 0969-8051 2004/11 [Refereed]
   

  The aim of this study was to develop simplified positron emission tomography measurement using [C-11]doxepin ([C-11]DOX) to evaluate histamine H-1 receptors (H1Rs) in human brains. We evaluated the correlation between the distribution volume (DV) of [C-11]DOX, estimated quantitatively with a two-compartment model, and the [C-11]DOX uptake obtained at various time intervals and normalized using the metabolite-corrected plasma radioactivity. We found that the static 70- to 90-min images normalized using the plasma radioactivity at 10 min postinjection reflected the DV of [C-11]DOX-H1R binding. (C) 2004 Elsevier Inc. All rights reserved.
• Quantitative analysis of adenosine A(1) receptors in human brain using positron emission tomography and [1-methyl-C-11]8-dicyclopropylmethyl-1-methyl-3-propylxanthine

  Y Kimura; K Ishii; N Fukumitsu; K Oda; T Sasakia; K Kawamura; K Ishiwata

  NUCLEAR MEDICINE AND BIOLOGY ELSEVIER SCIENCE INC 31 (8) 975 - 981 0969-8051 2004/11 [Refereed]
   

  Fully quantitative analysis of the adenosine A(1) receptor (A1R) in the brain with C-11-MPDX and positron emission tomography is reported. The kinetics is described using a two-tissue three-compartment model, and estimated binding potentials correspond well with the estimates made by Logan plot. The image of the binding potential of the MPDX is physiologically reasonable. We conclude that MPDX is applicable to the visualization of the A1Rs in the brain with Logan plot. (C) 2004 Elsevier Inc. All rights reserved.
• Potential of [C-11]TMSX for the evaluation of adenosine A(2A) receptors in the skeletal muscle by positron emission tomography

  K Ishiwata; M Mizuno; Y Kimura; K Kawamura; K Oda; T Sasaki; Y Nakamura; Muraoka, I; K Ishii

  NUCLEAR MEDICINE AND BIOLOGY ELSEVIER SCIENCE INC 31 (7) 949 - 956 0969-8051 2004/10 [Refereed]
   

  We examined the potential of [7-methyl-C-11]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine ([C-11]TMSX) for the assessment of adenosine A(2A) receptors in muscle. In rodents, specific binding of [C-11]TMSX was observed in muscle and heart by blockade with A(2A)-selective CSC and non-selective theophylline, but not with A(1)-selective DPCPX. Swimming exercise fluctuated radioligand-receptor binding in these tissues. In a PET study of two subjects, theophylline-infusion slightly deceased the distribution volume of [C-11]TMSX in the heart (20% reduction) and muscle (10% reduction), which suggested the specific binding. (C) 2004 Elsevier Inc. All rights reserved.
• Calibration procedure for a DOI detector of high resolution PET through a Gaussian mixture model

  E Yoshida; Y Kimura; K Kitamura; H Murayama

  IEEE TRANSACTIONS ON NUCLEAR SCIENCE IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC 51 (5) 2543 - 2549 0018-9499 2004/10 

  A depth of interaction detector is developed for the next generation of positron emission tomography (PET) scanners. The detector unit consists of 8 x 8 crystal blocks with four layers of 2 x 2 Gd2SiO5:Ce arrays coupled to a 52 mm square position sensitive photomultiplier tube (PS-PMT). Each scintillation event is mapped in a two-dimensional (2-D) position histogram through the relative ratio of the output signals of the PS-PMT. To facilitate high spatial resolution imaging, accurate crystal identification is needed. A statistical model based on the approach-of a Gaussian mixture model (GMM) is introduced for crystal identification. In the GMM, a cluster center and range attributed to individual peaks in the 2-D position histogram are defined. GMM can simultaneously estimate overlapping regions projected each crystal element. After block separation of 8 x 8 on the 2-D distribution, the crystal element regions are identified by the GMM in each block. The GMM method is applied two times, once for the cluster centers and once for determination of the range. These results are used to generate a look-up-table (LUT). This method successfully identified all crystal elements in the clustering area. By Monte Carlo simulation, we also proved that GMM method could choose LUT patterns to high resolution or high sensitivity with one parameter.
• Evaluation of in vivo selective binding of [C-11]doxepin to histamine H-1 receptors in five animal species

  K Ishiwata; K Kawamura; WF Wang; H Tsukada; N Harada; H Mochizuki; Y Kimura; K Ishii; R Iwata; K Yanai

  NUCLEAR MEDICINE AND BIOLOGY ELSEVIER SCIENCE INC 31 (4) 493 - 502 0969-8051 2004/05 [Refereed]
   

  The specific binding of [C-11]doxepin, which has been used as a radioligand for mapping histamine H-1 receptors in human brain by positron emission tomography, was evaluated in five animal species. In mice the [C-11]doxepin uptake was reduced by treatment with cold doxepin and two H-1 receptor antagonists, but not with H-2/H-3 antagonists. The specific binding evaluated with treatment with (+)-chlorpheniramine (H-1 antagonist) was in the range of 10-30% in mouse, rat, rabbit, and monkey, but was not detected in guinea pig. (C) 2004 Elsevier Inc. All rights reserved.
• Evaluation of [F-18]fluorinated sigma receptor ligands in the conscious monkey brain

  PH Elsinga; H Tsukada; N Harada; T Kakiuchi; K Kawamura; W Vaalburg; Y Kimura; T Kobayashi; K Ishiwata

  SYNAPSE WILEY-LISS 52 (1) 29 - 37 0887-4476 2004/04 [Refereed]
   

  PET-imaging of the sigma receptors is very helpful to understand processes, e.g., several central nervous system (CNS)-diseases in which the sigma receptors are involved. The [F-18]fluoroethylated analogs of SA4503 and SA5845 ([F-18]FE-SA4503 and [F-18]FE-SA5845) were evaluated in conscious monkeys to estimate its suitability for human application for PET. Conscious monkeys (Macaca Mulatta) were either scanned with [F-18]FE-SA4503 or [F-18]FE-SA5845 (n = 3 for both groups, 220 - 802 MBq). After a dynamic study of 120 min, radioactivity was displaced by intravenous (i.v.) injection of haloperidol (1 mg/kg). One month later the same set of three monkeys were scanned with [F-18]FE-SA4503 for 120 min and "cold" SA4503 (1 mg/kg) was infused to displace the radioactivity, and the other three monkeys were pretreated with haloperidol (1 mg/kg) before the 120-min PET-scan with [F-18]FE-SA5845. Cortical areas (cingulate, frontal, occipital, parietal, temporal), striatum, and thalamus showed high radioactivity uptake. Infusion of haloperidol displaced the radioactivity levels of the two radioligands. The same effect was found for [18F]FE-SA4503 after SA4503 displacement. Pretreatment with haloperidol blocked the [F-18]FE-SA5845 binding to give PET-images with low and uniform uptake in the brain. The findings demonstrated the reversible binding of the two radioligands. Metabolite analysis showed that 14% and 23% parent compound of [F-18]FE-SA5845 and [F-18]FE-SA4503, respectively, at 120 min postinjection was present in plasma. Kinetic analysis showed that the binding potential of [F-18]FE-SA5845 was higher in all brain regions than that of [F-18]FE-SA4503 (4.75-8.79 vs. 1.65-4.04). The highest binding potential was found in the hippocampus, followed by the cortical regions, thalamus, cerebellar hemisphere, striatum and vermis. Both [F-18]FE-SA compounds bound specifically to cerebral sigma receptors of the monkey and have potential for mapping sigma receptors in the human brain. (C) 2004 Wiley-Liss, Inc.
• Quantitative measurement of histamine H-1 receptors in human brains by PET and [C-11]doxepin

  H Mochizuki; Y Kimura; K Ishii; K Oda; T Sasaki; M Tashiro; K Yanai; K Ishiwata

  NUCLEAR MEDICINE AND BIOLOGY ELSEVIER SCIENCE INC 31 (2) 165 - 171 0969-8051 2004/02 [Refereed]
   

  The aim of this stud), is to establish a method for quantitative measurement of histamine H-1 receptor (H1R) in human brain by PET and ([C-11]doxepin ([C-11]DOX). The estimated parameters with a two-compartment model were stable for the initial values for parameter estimation but those with a three-compartment model were not. This finding suggests that the HIR measured by the [C-11]DOX and PET can be evaluated with a two-compartment model. (C) 2004 Elsevier Inc. All rights reserved.
• Regional differences in blood flow and oxygen consumption in resting muscle and their relationship during recovery from exhaustive exercise

  M Mizuno; Y Kimura; T Iwakawa; K Oda; K Ishii; K Ishiwata; Y Nakamura; Muraoka, I

  JOURNAL OF APPLIED PHYSIOLOGY AMER PHYSIOLOGICAL SOC 95 (6) 2204 - 2210 8750-7587 2003/12 [Refereed]
   

  This investigation evaluated regional differences in blood flow and oxygen consumption and their relationship in exercised muscle during recovery from exhaustive exercise. Five healthy men performed exhaustive one-legged cycling exercise. Positron emission tomography was used to measure blood flow, oxygen uptake, and oxygen extraction in the quadriceps femoris muscle before and after exercise. Regions of interest included five areas of the muscle (two proximal, one central, and two distal), which were evenly spaced across the muscle. Before exercise, blood flow and oxygen consumption decreased Significantly (P < 0.05) in the direction from the proximal to the distal portions; blood flow declined from 2.0 +/- 0.5 to 1.4 +/- 0.3 ml center dot 100 g(-1) center dot min(-1), and oxygen consumption decreased from 0.21 +/- 0.04 to 0.17 +/- 0.02 ml center dot 100 g(-1) center dot min(-1). In contrast, these gradients in blood flow and oxygen consumption diminished during recovery after exercise. Consequently, there was a positive relationship between changes in blood flow and oxygen consumption in an exercised muscle during recovery after exercise (r = 0.963, P < 0.01). These changes became larger in the direction from proximal to distal portions: blood flow increased from 2.9 +/- 0.7 to 3.9 +/- 0.8 and oxygen consumption from 1.4 +/- 0.1 to 1.8 +/- 0.4 times resting values. These results suggest that hemodynamic variables are heterogeneous within a muscle both at rest and during recovery from exercise and that there is a systematic difference in these variables in the direction from proximal to distal regions within the quadriceps femoris muscle.
• Regional differences in blood volume and blood transit time in resting skeletal muscle

  M Mizuno; Y Kimura; T Iwakawa; K Oda; K Ishii; K Ishiwata; Y Nakamura; Muraoka, I

  JAPANESE JOURNAL OF PHYSIOLOGY CENTER ACADEMIC PUBL JAPAN 53 (6) 467 - 470 0021-521X 2003/12 [Refereed]
   

  We examined regional differences in blood volume and transit time along the length of a resting skeletal muscle by positron emission tomography. In contrast, blood volume didn't change. The blood transit time increased significantly from proximal to distal portions, suggesting that blood flow velocity slows even though there are no changes in blood volume.
• Regional differences in blood volume and blood transit time in resting skeletal muscle

  M Mizuno; Y Kimura; T Iwakawa; K Oda; K Ishii; K Ishiwata; Y Nakamura; Muraoka, I

  JAPANESE JOURNAL OF PHYSIOLOGY CENTER ACADEMIC PUBL JAPAN 53 (6) 467 - 470 0021-521X 2003/12 

  We examined regional differences in blood volume and transit time along the length of a resting skeletal muscle by positron emission tomography. In contrast, blood volume didn't change. The blood transit time increased significantly from proximal to distal portions, suggesting that blood flow velocity slows even though there are no changes in blood volume.
• An increase of sigma(1) receptors in the aged monkey brain

  K Kawamura; Y Kimura; H Tsukada; T Kobayashi; S Nishiyama; T Kakiuchi; H Ohba; N Harada; K Matsuno; K Ishii; K Ishiwata

  NEUROBIOLOGY OF AGING ELSEVIER SCIENCE INC 24 (5) 745 - 752 0197-4580 2003/09 [Refereed]
   

  We evaluated in vivo the effect of aging on the sigma, receptors in the monkey brain by the quantitative analysis of the binding of [C-11]SA4503 to sigma, receptors with positron emission tomography. Based on a three-compartment model, the influx rate constant K-1 of [C-11]SA4503 from plasma to brain across the blood-brain barrier in all 10 regions investigated became smaller in the aged monkeys (20-28 years old, n = 5) than in the young adult monkeys (4-8 years old, it = 5), but the reduction was not significant due to the individual differences. On the other hand, the binding potential, which was calculated as the ratio of the association rate constant k(3) to the dissociation rate constant k(4) for the binding of [C-11]SA4503 to sigma, receptors in the brain, significantly increased in nine of the brain regions of the aged monkeys to the 160-210% levels of the young monkeys. We concluded that the sigma, receptor binding sites increased in the aging process of the monkey brain. (C) 2002 Elsevier Science Inc. All rights reserved.
• Potential of an adenosine A(2A) receptor antagonist [C-11]TMSX for myocardial imaging by positron emission tomography: a first human study

  K Ishiwata; K Kawamura; Y Kimura; K Oda; K Ishii

  ANNALS OF NUCLEAR MEDICINE JAPANESE SOCIETY NUCLEAR MEDICINE 17 (6) 457 - 462 0914-7187 2003/09 [Refereed]
   

  In previous in vivo studies with mice, rats, cats and monkeys, we have demonstrated that [7-methyl-C-11]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine ([C-11]TMSX) is a potential radioligand for mapping adenosine A(2A) receptors of the brain by positron emission tomography (PET). In the present study, we studied the potential of [C-11]TMSX for myocardial imaging. Uptake of radioactivity by the heart was high and gradually decreased after an intravenous injection of [C-11]TMSX into mice. In metabolite analysis, 54% and 76% of the radioactivity in plasma and heart, respectively, were present as the unchanged form of [C-11]TMSX 60 min postinjection. The myocardial uptake was reduced by carrier-loading and by co-injection of an adenosine A(2A) antagonist CSC, but not by co-injection of an adenosine A(1) antagonist DPCPX. Pretreatment with a high dose of a non-selective antagonist theophylline also reduced the myocardial uptake of [C-11]TMSX. These findings demonstrate the specific binding of [C-11]TMSX to adenosine A(2A) receptors in the heart. Finally we successfully performed the myocardial imaging by PET with [C-11]TMSX in a normal volunteer. A graphical analysis by Logan plot supported the receptor-mediated uptake of [C-11]TMSX. Peripherally [C-11]TMSX was very stable in human: >90% of the radioactivity in plasma was detected as the unchanged form in a 60-min study. We concluded that [C-11]TMSX PET has the potential for myocardial imaging.
• Imaging of adenosine A(1) receptors in the human brain by positron emission tomography with [C-11]MPDX

  N Fukumitsu; K Ishii; Y Kimura; K Oda; T Sasaki; Y Mori; K Ishiwata

  ANNALS OF NUCLEAR MEDICINE JAPANESE SOCIETY NUCLEAR MEDICINE 17 (6) 511 - 515 0914-7187 2003/09 [Refereed]
   

  We report the first clinical PET study using [1-methyl-C-11]8-dicyclopropylmethyl-1-methyl-3-propylxanthine ([C-11]MPDX) for imaging adenosine A(1) receptors in the human brain. The binding of [C-11]MPDX evaluated quantitatively as the distribution volume by a graphical analysis was high in the striatum and thalamus, and low in the cerebellum. The distribution pattern of [C-11]MPDX was coincident with that of adenosine A(1) receptors in vitro reported previously, and was different from those of blood flow and [F-18]FDG. The [C-11]MPDX PET has the potential for mapping adenosine A(1) receptors in the human brain.
• Increased regional cerebral blood flow but normal distribution of GABA(A) receptor in the visual cortex of subjects with early-onset blindness

  M Mishina; M Senda; M Kiyosawa; K Ishiwata; AG De Volder; H Nakano; H Toyama; K Oda; Y Kimura; K Ishii; T Sasaki; M Ohyama; Y Komaba; S Kobayashi; S Kitamura; Y Katayama

  NEUROIMAGE ACADEMIC PRESS INC ELSEVIER SCIENCE 19 (1) 125 - 131 1053-8119 2003/05 [Refereed]
   

  Before the completion of visual development, visual deprivation impairs synaptic elimination in the visual cortex. The purpose of this study was to determine whether the distribution of central benzodiazepine receptor (BZR) is also altered in the visual cortex in subjects with early-onset blindness. Positron emission tomography was carried out with [O-15]water and [C-11]flumazenil on six blind subjects and seven sighted controls at rest. We found that the CBF was significantly higher in the visual cortex for the early-onset blind subjects than for the sighted control subjects. However, there was no significant difference in the BZR distribution in the visual cortex for the subject with early-onset blindness than for the sighted control subjects. These results demonstrated that early visual deprivation does not affect the distribution of GABA(A) receptors in the visual cortex with the sensitivity of our measurements. Synaptic elimination may be independent of visual experience in the GABAergic system of the human visual cortex during visual development. (C) 2003 Elsevier Science (USA). All rights reserved.
• Preclinical studies on [C-11]TMSX for mapping adenosine A(2A) receptors by positron emission tomography

  K Ishiwata; WF Wang; Y Kimura; K Kawamura; K Ishii

  ANNALS OF NUCLEAR MEDICINE JAPANESE SOCIETY NUCLEAR MEDICINE 17 (3) 205 - 211 0914-7187 2003/05 [Refereed]
   

  In previous in vivo studies with mice, rats and monkeys, we have demonstrated that [C-11]TMSX ([7-methyl-C-11]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine) is a potential radioligand for mapping adenosine A(2A) receptors of the brain by positron emission tomography (PET). In the present study, we performed a preclinical study. A suitable preparation method for [C-11]TMSX injection was established. The radiation absorbed-dose by [C-11]TMSX in humans estimated from the tissue distribution in mice was low enough for clinical use, and the acute toxicity and mutagenicity of TMSX were not found. The striatal uptake of [C-11]TMSX in mice was reduced by pretreatment with,theophylline at the dose of 10 and 100 mg/kg, suggesting that the [C-11]TMSX PET should be carefully performed in the patients received with theophylline. We have concluded that [C-11]TMSX is-suitable for mapping adenosine A(2A) receptors in the human brain by PET.
• Parkinson 病の線条体における節前・節後dopamine 機能の相関的解析, --- A Novel Voxel Based Analysis ---

  鈴木正彦; 井上聖啓; 北村伸; 三品雅洋; 三谷和子; 山之内博; 織田圭一; 木村裕一; 石渡喜一; 石井賢二

  CI学会誌 25 (4) 237 - 244 2003 [Refereed]
  
• Regional difference in blood flow and oxygen consumption in exercise muscle and their relationship during recovery fron exhausive exercise

  J Appl Physiolo 95, 2204-2210 2003
• Regional differences in blood flow and oxygen consumption in exercised muscle and their relationship curing recovery from exhausive exercise

  Masaki Mizuno; Yuichi Kimura; Takashi Iwakawa; Keiichi Oda; Kenji Ishii; Kiichi Ishiwata; Yoshio Nakamura; Isao Muraoka

  J. of. Appl Physiol 53 467 - 470 2003
• [Three-dimensional projection display of striatum dopamine function measured by PET].

  Oda K; Ishii K; Kimura Y; Ishiwata K

  Nihon Hoshasen Gijutsu Gakkai zasshi 58 (12) 1573 - 1578 0369-4305 2002/12 [Refereed]
   

  [(11)C]CFT and[(11)C]raclopride images obtained by positron emission tomography (PET) are used to evaluate pre-synaptic dopamine transporter availability and post-synaptic dopamine D(2) receptor binding, respectively. A combined study with these tracers is useful for the differential diagnosis of Parkinson's disease. We generated three-dimensional (3D) animations of striatum PET images for the diagnosis of Parkinson's disease. Brain images of a normal subject and a typical Parkinson's disease patient with[(11)C]CFT and[(11)C]raclopride were obtained using a PET camera. Three-dimensional animations were generated from serial maximum intensity projection (MIP) images created by gradually changing the projection angle. Furthermore, the striatum images extracted from brain data were superimposed over a brain surface magnetic resonance (MR) image that was created by the volume-rendering method, and 3D animations were similarly generated. The present 3D animations were clinically useful for the differential diagnosis of brain diseases, because we were able to observe distributions of[(11)C]CFT and[(11)C]raclopride from any angle and to grasp at a glance the regional differences of distributions in reference to anatomical landmarks.
• Preclinical studies on [C-11]MPDX for mapping adenosine A(1) receptors by positron emission tomography

  K Ishiwata; T Nariai; Y Kimura; K Oda; K Kawamura; K Ishii; M Senda; S Wakabayashi; J Shimada

  ANNALS OF NUCLEAR MEDICINE JAPANESE SOCIETY NUCLEAR MEDICINE 16 (6) 377 - 382 0914-7187 2002/09 [Refereed]
   

  In previous in vivo studies with mice, rats and cats, we have demonstrated that [C-11]MPDX ([1-methyl- C-11]8-dicyclopropylmethyl-1-methyl-3-propylxanthine) is a potential radioligand for mapping adenosine A(1) receptors of the brain by positron emission tomography (PET). In the present study, we performed a preclinical study. The radiation absorbed-dose by [C-11]MPDX in humans estimated from the tissue distribution in mice was low enough for clinical use, and the acute toxicity and mutagenicity of MPDX were not found. The monkey brain was clearly visualized by PET with [C-11]MPDX. We have concluded that [C-11]MPDX is suitable for mapping adenosine A(1) receptors in the human brain by PET.
• Fast formation of statistically reliable FDG parametric images based on clustering and principal components

  Y Kimura; M Senda; NM Alpert

  PHYSICS IN MEDICINE AND BIOLOGY IOP PUBLISHING LTD 47 (3) 455 - 468 0031-9155 2002/02 [Refereed]
   

  Formation of parametric images requires voxel-by-voxel estimation of fate constants, a process sensitive to noise and computationally demanding. A model-based clustering method for a two-parameter model (CAKS) was extended to the FDG three-parameter model. The concept was to average voxels with similar kinetic signatures to reduce noise. Voxel kinetics were categorized by the first two principal components of the tissue time-activity curves for all voxels. k(2) and k(3) were estimated cluster-by-cluster, and K-1 was estimated voxel-by-voxel within clusters. When CAKS was applied to simulated images with noise levels similar to brain FDG scans, estimation bias was well suppressed, and estimation errors were substantially smaller-1.3 times for K-i and 1.5 times for k(3)-than those of conventional voxel-based estimation. The statistical reliability of voxel-level estimation by CAKS was comparable with ROI analysis including 100 voxels. CAKS was applied to clinical cases with Alzheimer's disease (ALZ) and cortico basal degeneration (CBD). In ALZ, the affected regions had low K-i(K(1)k(3)/(k(2) + k(3))) and k(3). In CBD, K-i was low, but k(3) was preserved. These results were consistent with ROI-based kinetic analysis. Because CAKS decreased (lie number of invoked estimations, the calculation time was reduced substantially. In conclusion, CAKS has been extended to allow parametric imaging of a three-compartment model. The method is computationally efficient, with low bias and excellent noise properties.
• 線条体ドーパミン機能PET画像の三次元表示

  織田圭一; 石井賢二; 木村裕一; 石渡喜一

  日本放射線技術学会誌 58 (12) 1573 - 1578 2002 [Refereed]
  
• Application of visual evoked potentials for preoperative estimation of visual function in eyes with dense cataract

  H Mori; K Momose; N Nemoto; F Okuyama; Y Kimura; M Kiyosawa; M Mochizuki

  GRAEFES ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY SPRINGER 239 (12) 915 - 922 0721-832X 2001/12 [Refereed]
   

  Purpose: To determine whether the temporal frequency characteristics of the visual system as determined by visually evoked potentials (VEP) can be used for a preoperative estimation of the visual function in eyes with cataracts. Methods: Light stimuli driven by a pseudorandom binary sequence (PRBS) of 40950 ms duration were presented and EEG recordings were made from 13 control and 20 patients with cataracts preoperatively and 1 week after cataract operation. The first kernel of the PRBS-VEP was obtained as the first-order cross-correlation function between PRBS and PRBS-VER The Fourier transform of this function was used as the temporal frequency characteristic (TFC). Results: The mean +/- standard deviation of the latency and amplitude of the VEP in normal controls were 110.8 +/- 4.3 ms and 2.01 +/- 0.67 muV, respectively. A high correlation (r > 0.7) between the pre- and postoperative VEP waveform was obtained in 13 eyes (65%), and 14 eyes (70%) in the VEP-TFC curves. The sensitivity of the examination was 73%, 27%, and 91% for the latency, amplitude and TFC of the VEP, respectively. The specificity of the examination was 67%, 100%, and 89% for the same measures. Eleven of 12 eyes with abnormal TFC preoperatively showed retinal or optic nerve lesions postoperatively. False-negative results were seen in cases with delayed corneal edema. Conclusion: Postoperative visual function of patients with cataracts can be predicted by preoperative measurement of the TFC obtained by PRBS-VEP.
• Comparison of parametric FBP and OS-EM reconstruction algorithm images for PET dynamic study

  K Oda; H Toyama; K Uemura; Y Ikoma; Y Kimura; M Senda

  ANNALS OF NUCLEAR MEDICINE JAPANESE SOCIETY NUCLEAR MEDICINE 15 (5) 417 - 423 0914-7187 2001/10 [Refereed]
   

  An ordered subsets expectation maximization (OS-EM) algorithm is used for image reconstruction to suppress image noise and to make non-negative value images. We have applied OS-EM to a digital brain phantom and to human brain F-18-FDG PET kinetic studies to generate parametric images. A 45 min dynamic scan was performed starting injection of FDG with a 2D PET scanner. The images were reconstructed with OS-EM (6 iterations, 16 subsets) and with filtered backprojection (FBP), and K1, k2 and k3 images were created by the Marquardt non-linear least squares method based on the 3-parameter kinetic model. Although the OS-EM activity images correlated fairly well with those obtained by FBP, the pixel correlations were poor for the k2 and k3 parametric images, but the plots were scattered along the line of identity and the mean values for K1, k2 and k3 obtained by OS-EM were almost equal to those by FBP. The kinetic fitting error for OS-EM was no smaller than that for FBP. The results suggest that OS-EM is not necessarily superior to FBP for creating, parametric images.
• Auditory triggered mental imagery of shape involves visual association areas in early blind humans

  AG De Volder; H Toyama; Y Kimura; M Kiyosawa; H Nakano; A Vanlierde; MC Wanet-Defalque; M Mishina; K Oda; K Ishiwata; M Senda

  NEUROIMAGE ACADEMIC PRESS INC 14 (1) 129 - 139 1053-8119 2001/07 [Refereed]
   

  Previous neuroimaging studies identified a large network of cortical areas involved in visual imagery in the human brain, which includes occipitotemporal and visual associative areas. Here we test whether the same processes can be elicited by tactile and auditory experiences in subjects who became blind early in life. Using positron emission tomography, regional cerebral blood flow was assessed in six right-handed early blind and six age-matched control volunteers during three conditions: resting state, passive listening to noise sounds, and mental imagery task (imagery of object shape) triggered by the sound of familiar objects. Activation foci were found in occipitotemporal and visual association areas, particularly in the left fusiform gyrus (Brodmann areas 19-37), during mental imagery of shape by both groups. Since shape imagery by early blind subjects does involve similar visual structures as controls at an adult age, it indicates their developmental crossmodal reorganization to allow perceptual representation in the absence of vision. (C) 2001 Academic Press.
• Mapping of CNS sigma(1) receptors in the conscious monkey: Preliminary PET study with [C-11]SA4503

  K Ishiwata; H Tsukada; K Kawamura; Y Kimura; S Nishiyama; T Kobayashi; K Matsuno; M Senda

  SYNAPSE WILEY-LISS 40 (3) 235 - 237 0887-4476 2001/06 [Refereed]
  
• Report on the 7th Asia and Oceania Congress of Nuclear Medicine and Biology

  ODA KEIICHI; KIMURA Y.; ISHII K.; SENDA M.; UEMURA K.; TOYAMA H.

  Japanese Journal of Radiological Technology Japanese Society of Radiological Technology 57 (7) 803 - 805 0369-4305 2001
• Preclinical evaluation of [C-11]SA4503: radiation dosimetry, in vivo selectivity and PET imaging of sigma(1) receptors in the cat brain

  K Kawamura; K Ishiwata; Y Shimada; Y Kimura; T Kobayashi; K Matsuno; Y Homma; M Senda

  ANNALS OF NUCLEAR MEDICINE JAPANESE SOCIETY NUCLEAR MEDICINE 14 (4) 285 - 292 0914-7187 2000/08 [Refereed]
   

  Our previous in vivo study with rats has demonstrated that C-11-labeled 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine ([C-11]SA4503) is a potential radioligand for mapping CNS sigma(1) receptors by positron emission tomography (PET). In the present study, we further characterized this ligand. The radiation absorbed-dose of [C-11]SA4503 in humans estimated with the tissue distribution in mice, was higher in the liver, kidney and pancreas than in other organs studied, but was low enough for clinical use. The brain uptake of [(11)]SA4503 in mice was reduced to approximately 60-70% by co-injection of carrier SA4S03 and haloperidol, but not by co-injection of any of six ligands for sigma(2) or other receptors, for which SA4503 showed in vitro >100 times weaker affinity than for sigma(1) receptor. In. the cat brain, the uptake in the cortex was higher than that in the cerebellum. The radioactivity in the cortex and cerebellum accumulated for the first 10 min and then gradually decreased until 81.5 min in the baseline measurement, but rapidly decreased in the carrier-loading condition. The receptor-mediated uptake was estimated to be approximately 60-65% of the total radioactivity in. the cortex and cerebellum at 76 min after tracer injection. We have concluded that [C-11]SA4S03 has she potential for mapping sigma(1) receptor by PET.
• Intrasubject correlation between static scan and distribution volume images for [C-11]flumazenil PET

  M Mishina; M Senda; Y Kimura; H Toyama; K Ishiwata; M Ohyama; T Nariai; K Ishii; K Oda; T Sasaki; S Kitamura; Y Katayama

  ANNALS OF NUCLEAR MEDICINE JAPANESE SOCIETY NUCLEAR MEDICINE 14 (3) 193 - 198 0914-7187 2000/06 [Refereed]
   

  Accumulation of [C-11]flumazenil (FMZ) reflects central nervous system benzodiazepine receptor (BZR). We searched for the optimal time for a static PET scan with FMZ as semi-quantitative imaging of BZR distribution. In 10 normal subjects, a dynamic series of decay-corrected PET scans was performed for 60 minutes, and the arterial blood was sampled during the scan to measure radioactivity and labeled metabolites. We generated 13 kinds of "static scan" images from the dynamic scan in each subject, and analyzed the pixel correlation for these images versus distribution volume (DV) images. We also analyzed the time for the [C-11]FMZ in plasma and tissue to reach the equilibrium. The intra-subject pixel correlation demonstrated that the "static scan" images for the period centering around 30 minutes post-injection had the strongest linear correlation with the DV image. The ratio of radioactivity in the cortex to that in the plasma reached a peak at 40 minutes after injection. Considering the physical decay and patient burden, we conclude that the decay corrected static scan for [C-11]FMZ PET as semi-quantitative imaging of BZR distribution is to be optimally acquired from 20 to 40 minutes after injection.
• Generation of fractal dimension images and its application to automatic edge detection in brain MRI

  K Uemura; H Toyama; S Baba; Y Kimura; M Senda; A Uchiyama

  COMPUTERIZED MEDICAL IMAGING AND GRAPHICS PERGAMON-ELSEVIER SCIENCE LTD 24 (2) 73 - 85 0895-6111 2000/03 [Refereed]
   

  We have developed four methods to generate a fractal dimension image and have applied them to the brain MRI. We have adopted four types of scanning methods, "CONVENTIONAL", "OVERLAPPING", "SYMMETRIC" and "FOLDED" to estimate the fractal dimension. The first three methods show almost the same fractal dimension images and their values were between two and three. In the "FOLDED" method, we were able to obtain the images in which the edge of a narrow region including dura and scalp surrounding the brain was selectively enhanced in the T1-weighted MRI, This is found to be a new edge-enhancing filter. We could remove the surrounding structure of the brain by using these filtered images and detect the edge of the brain surface automatically. The brain surface data can be used for various applications such as three-dimensional surface display and registration of inter-modal brain images. (C) 2000 Elsevier Science Ltd. All rights reserved.
• Generation of Fractal Dimension Images and its Application to Automatic Edge Detection in Brain MRI

  Kouji Uemura; Hinako Toyama; Shigeyuki Baba; Yuichi Kimura; Michio Senda; Akihiko Uchiyama

  Comp Med Image Graph 24 (73) 85 - 85 2000 [Refereed]
  
• Assesment of Glucose Metabolism in Exercised Muscle with Positron Emission Tomography

  Kazunobu Ohmori; Shin-ya Kuno; Yuichi Kimura; Masaki Mizuno; Yoshio Nakamura; Isao Muraoka; Fukio Ohta; Masahiro Mishina; Hinako Toyama; Michio Senda

  Adv Exerc Sports Physiol 6 (3) 81 - 84 2000 [Refereed]
  
• Improved signal-to-noise ratio in parametric images by cluster analysis

  Y Kimura; H Hsu; H Toyama; M Senda; NM Alpert

  NEUROIMAGE ACADEMIC PRESS INC 9 (5) 554 - 561 1053-8119 1999/05 [Refereed]
   

  Parametric images are formed by analyzing the concentration history of every voxel in PET data sets. Because PET concentration data at the voxel level are rather noisy, noise propagation into the parametric image is often quite noticeable. To address this problem, a model-based clustering method has been developed to generate parametric images. The basic idea of the clustering method is to average over voxels whose concentration histories have the same shape. We applied the method to a two-parameter (K-1, k(2)) compartment model of local cerebral blood flow. The statistic R = integral tC(t) dtl integral C(t) df = integral te(-k2t) x C-a(t) dtl integral e(-k2t) x C-a(t) dt classifies curves in terms of k(2), where C(t) and C,(t) denote the tissue and blood concentration histories, respectively, and x is the convolution operator. Simulation studies of noise propagation in the clustering statistic showed that 30% voxel noise yielded a 2% standard deviation in R. Parametric images of blood flow and partition coefficient were computed for an O-15 study, with and without clustering. Cluster size affected bias, statistical precision, and computation time. With clusters of 400 voxels, the variance of the flow parameter was around 1/50 smaller with clustering, with negligible bias and a computation time of 30 s on a 64-MHz workstation for 15 x 128 x 128 images with MATLAB 5.1. (C) 1999 Academic Press.
• A comparison between cyclists and noncyclists of joint torque of the lower extremities during pedaling

  Hidetoshi Hoshikawa; Keiichi Tamaki; Hiroshi Fujimoto; Yuichi Kimura; Hirokazu Saito; Yoshiro Satoh; Yoshio Nakamura; Isao Muraoka

  Japanese Journal of Physical Fitness and Sports Medicine Japanese Society of Physical Fitness and Sports Medicine 48 (5) 547 - 558 0039-906X 1999 [Refereed]
   

  The purpose of this study was to compare the effect between cyclists and noncyclists of pedal rates on ankle, knee, and hip joint torque during pedaling exercises. Six male cyclists (CY) and seven male noncyclists (NC) pedaled at 40, 60, 90 and 120 rpm with a power output of 200 W. The lower limb was modeled as three rigid segment links constrained to plane motion. Based on the Newton-Euler method, the equation for each segment was constructed and solved on a computer using pedal force, pedal, crank, and lower limb position data to calculate torque at the ankle, knee, and hip joints. The average planter flexor torque decreased with increasing pedal rates in both groups. The average knee extensor torque for CY decreased up to 90 rpm, and then leveled off at 120 rpm. These results were similar to NC. The average knee flexor torque in both groups remained steady over all pedal rates. The average hip extensor torque for CY decreased significantly up to 90 rpm where it showed the lowest value, but increased at 120 rpm. For NC, the average hip extensor torque did not decrease at 90 rpm compared with 60 rpm, and was significantly higher than CY at 120 rpm (CY : 28.1 ± 9.0 Nm, NC : 38.6 ± 6.7 Nm, p < 0.05). The average hip flexsor torque for NC at 120 rpm increased significanly from 90 rpm, and was significantly higher than CY (CY : 11.6 ± 2.9 Nm, NC : 22.6 ± 11.8 Nm, p < 0.05). These results suggest that it would be better for cyclists to select a pedal rate of between 90 to 110 rpm to minimize joint torque, and, as a result, reduce peripheral muscle fatigue.
• Visual temporal frequency characteristics determined by pseudorandom stimuli

  K Momose; M Kiyosawa; N Nemoto; Y Kimura; F Okuyama; M Senda

  INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE ASSOC RESEARCH VISION OPHTHALMOLOGY INC 40 (1) 50 - 54 0146-0404 1999/01 [Refereed]
   

  PURPOSE. TO investigate whether a rapid and practical determination of the temporal frequency characteristic (TFC) of the visual system can be obtained by using the visually evoked potentials (VEPs) elicited by pseudorandom binary sequence (PRBS) stimulation. METHODS. VEPs were recorded from eight volunteers. For the conventional steady state VEPs (S-VEP), the eye was stimulated with five stimulus frequencies. To acquire the PRBS-VEPs, the eye was stimulated with a PRBS stimulus for 40 seconds. The TFC for the S-VEP was calculated from the root mean squared amplitude for each frequency using Fourier transform. For the PRBS stimulus, a cross-correlation function between PRBS (x[t]) and PRBS-VEP (y[t]) was calculated to obtain the TFC. RESULTS. The TFCs obtained by the PRBS and S-VEP methods were highly correlated (P < 0.05), and the TFC curves resembled those in the literature. Most important, the data necessary to determine the TFCs using the PRBS stimulus could be obtained in 4 minutes, whereas that for the S-VEP required 60 minutes for the two eyes. CONCLUSIONS. The high correlation between the TFCs obtained by the two methods indicated that the PRBS technique gives a good measure of the TFC of the human visual system. The significantly shorter time required for this method demonstrated that it is a practical method for determining the linear (and nonlinear) property of the visual system and that it may be useful in clinical applications.
• Mapping visual field with positron emission tomography by mathematical modeling of the retinotopic organization in the calcarine cortex

  S Endo; H Toyama; Y Kimura; K Ishii; M Senda; M Kiyosawa; A Uchiyama

  IEEE TRANSACTIONS ON MEDICAL IMAGING IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC 16 (3) 252 - 260 0278-0062 1997/06 [Refereed]
   

  We developed an objective and quantitative method of mapping the human visual field with positron emission tomography (PET) and magnetic resonance image (MRI). The regional cerebral blood flow (rCBF) images were acquired with H-2(15)}O- PET under visual fixation as well as under visual stimulation with flickering diodes arranged along the ring at 0 degrees, 3 degrees, 7 degrees, 14 degrees, 21 degrees, or 29 degrees from the fixation point, After coregistration of PET and MR images, we extracted the surface of the calcarine cortex from the MR images and unfolded it to a two-dimensional (2-D) elliptic plane, on which the activated PET images were superimposed. Then we transformed the unfolded calcarine cortex into the visual field coordinates using the complex logarithmic function proposed by Schwartz. A large individual variation was observed in the retinotopical organization as well as in the morphology of the calcarine cortex. The formula was valid only within 15 degrees from the center of the visual field. The constant parameter in the formula was estimated to be 1.5. The cortical linear magnification factor was 12.1, 2.8, and 1.6 at 0, 5, and 10 degrees, respectively, The areas of the central 10 degrees and 40 degrees in the visual field correspond to 50% and 81% of the calcarine surface, respectively.
• Fractal Dimension, Noise and Spatial Resolution.

  Uemura Koji; Toyama Hinako; Kobayashi Akio; Yamada Takamitsu; Kimura Yuichi; Senda Michio; Uchiyama Akihiko

  Proceedings of the Annual Conference of Biomedical Fuzzy Systems Association Biomedical Fuzzy Systems Association 10 43 - 46 1997 

  Fractal dimension images were generated by box-counting method for MRI and PET glucose metabolic images of the brain. An effect of the noise and spatial resolution on the value of fractal dimension was investigated by smoothing the brain images in a normal volunteer and a patient with corticobasal degeneration. In MRIs with high resolution and low noise, mean values of fractal dimension in the region of degenerated cerebral cortex was shown to be lower than those in the normal cerebral cortex and the relation was not changed by ten times smoothing, which is blurring the image and is reducing the noise. Then the low value of the fractal dimension in the lesion shows character of the corticobasal degeneration. In PET images with low resolution and high noise, however, the difference of the fractal dimension, between the normal and the CBD patient, was disappeared by more than 4 times smoothing. This result shows the spatial resolution of the PET images is critical to evaluate the characteristics of the texture by fractal dimension.
• Personal identification by bathtub ECG

  Mitsuhiro Ogawa; Yuichi Kimura; Toshiyo Tamura; Tatsuo Togawa

  Japanese Journal of Medical Electronics and Biological Engineering 35 (1) 82 - 89 0021-3292 1997 

  In this paper we describe personal identification method by using ECG signals obtained from the bathtub ECG. Difference of ECG signals between subjects was used as an index of personal identification. The measured ECG was processed by the wavelet transformation to reduce, the input data of neural network. The network was trained by the back propagation learning algorithm. Personal identification was achieved 89% classification rate in 8 subjects who don't have blood relation. And 92% classification rate was achieved in a family which have 5 members. This method is available to make personal identification in bathing monitor.
• 浴槽内心電図を用いた個人識別

  小川光洋; 木村裕一; 田村俊世; 戸川達男

  医用電子と生体工学 35 (1) 82 - 89 1997 [Refereed]
  
• Data Analysis for Medical Images using Fractal Dimension.

  Toyama Hinako; Uemura Kouji; Kobayashi Akio; Kimura Yuichi; Senda Michio

  Proceedings of the Annual Conference of Biomedical Fuzzy Systems Association Biomedical Fuzzy Systems Association 9 74 - 77 1996 

  Fractal dimension images were generated by a pixel-by-pixel method. The fractal dimension at the target pixel was estimated as Hausdorff dimension (D) which is defined as n (r)=D (1/r) using the surrounding NxN unit cell, where r varies 1 to N-1 and n (r) is the number of unit voxel r covering the three dimensional surface of the unit cell N.We apply this method for the glucose metabolic rate and the oxygen metabolic images of the brain in 5 patients with Alzheimer disease and in 2 normal cases. Mean fractal dimension of the cerebral functional images increased and the fitting error decreased as N increased. In a patient with typical Alzheimer disease, low glucose metabolic rate regions with higher or lower fractal dimension were observed.
• Fully automated ECG data acquisition in a bathtub

  Mitsuhiro Ogawa; Yuichi Kimura; Toshiyo Tamura; Tatsuo Togawa

  Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings (1) 55 - 56 0589-1019 1996 

  In apply to home health monitoring, we attempted ECG recording in a bathtub. For fully automated data acquisition, personal identification technique was introduced in which differences in ECG waveforms among individuals were used. The wavelet transform was applied to reduce the ECG data, and a neural network was introduced to create a discrimination algorithm by learning. In a preliminary study, it was shown that more than 91% of ECG data could be identified correctly among a family of five members.
• Basic study on relationship between estimated rate constants and noise in FDG kinetic analysis

  Yuichi Kimura; Hinako Toyama; Michio Senda

  Kakuigaku 33 (2) 107 - 114 0022-7854 1996 [Refereed]
   

  For accurate estimation of the rate constants in 18F-FDG dynamic study, the shape of the estimation function (Φ) is crucial. In this investigation, the relationship between the noise level in tissue time activity curve and the shape of the least squared estimation function which is the sum of squarred error between a function of model parameters and a measured data is calculated in 3 parameter model of 18F-FDG. In the first simulation, by using actual plasma time activity curve, the true tissue curve was generated from known sets of rate constants ranging 0.05 ≤ k 1 ≤ 0.15, 0.1 ≤ k 2 ≤ 0.2 and 0.01 ≤ k 3 ≤ 0.1 in 0.01 step. This procedure was repeated under various noise levels in the tissue time activity curve from 1 to 8% of the maximum value in the tissue activity. In the second simulation, plasma and tissue time activity curves from clinical 18F-FDG dynamic study were used to calculate the Φ. Results are: (1) In the noise-free case, because the global minima is separated from neighboring local minimums, it was easy to find out the optimum point. However, with increasing noise level, the optimum point was buried in many neighboring local minima. Making it difficult to find out the optimum point. (2) The optimum point was found within 20% of the convergence point by standard non-linear optimization method. (3) The shape of Φ for the clinical data was similar to that with the noise level of 3 or 5% in the first simulation. Therefore direct search within the area extending 20% from the result of usual non-linear curve fitting procedure is recommended for accurate estimation of the constants.
• 一様吸収体における2 次元PET 画像の統計ノイズ特性に関す る分析

  村山秀雄; 野原功全; 木村裕一; 篠原広行

  医用画像工学会誌 14 (1) 107 - 114 1996 [Refereed]
  
• FDG動態計測における速度定数推定値の分布とノイズの関係に関する 基礎的検討

  木村裕一; 外山比南子; 千田道雄

  核医学 33 (2) 107 - 114 1996 [Refereed]
  
• 7. Application of soft computing technique on data analysis in nuclear medicine.

  Toyama H.; Kimura Y.; Taguchi A.; Uemura K.; Matsumura Y.; Kobayashi A.; Senda M.

  Proceedings of the Annual Conference of Biomedical Fuzzy Systems Association Biomedical Fuzzy Systems Association 8 29 - 30 1995 

  核医学画像データの解析には、モデルに基づいた生体臓器機能定量、画像分布の特徴抽出及び機能局在診断のための解析などがある。最近医学分野でもその応用が活発なソフトコンピューティング技術を、このような画像データの解析に応用することを目的としていくつかの試みを行った。まず、脳における糖代謝モデルにおいて、非線形最小自乗法によるパラメータ推定の演算時間を高速化するために、ファジー推論を応用し、若干の改善を見た。また、心筋画像のテクスチャー解析にフラクタル次元を用いた。血流分布と酸素代謝画像のフラクタル次元画像を作成し、そのヒストグラムを比較した結果、酸素代謝画像の次元が高かった。フラクタル次元算出法を変形することによって、臓器画像の輪郭を強調できることが解り、MRIとPET画像位置合わせに必要な輪郭の自動抽出に用いた。このような経験から、今後の核医学画像データ処理におけるソフトコンピューティング技術の応用について考察する。
• 18F-FDG脳動態解析によるパラメトリック画像の作成とその相関関係

  外山 比南子; 木村 裕一; 石井 賢二; 千田 道雄; 織田 圭一; 石渡 喜一; 佐々木 徹

  核医学 (一社)日本核医学会 31 (7) 711 - 711 0022-7854 1994/07
• 局所脳萎縮を示す変性疾患における脳ブドウ糖代謝 FDG動態解析による検討

  石井 賢二; 外山 比南子; 千田 道雄; 織田 圭一; 石渡 喜一; 佐々木 徹; 石井 信一; 木村 裕一

  核医学 (一社)日本核医学会 31 (7) 714 - 714 0022-7854 1994/07
• 医用画像解析におけるフラクタル次元画像の応用(一般講演4,ファジィ理論、ニューロサイエンス、およびカオスの医療と健康への応用を考える)

  上村 幸司; 外山 比南子; 木村 裕一; 仁科 光貴; 千田 道雄; 内山 明彦

  バイオメディカル・ファジィ・システム学会大会講演論文集 バイオメディカル・ファジィ・システム学会 7 44 - 47 1994
• PETとMRI画像の重ね合わせ 自動化への試み

  馬場 茂幸; 外山 比南子; 木村 裕一; 千田 道雄; 石井 賢二; 織田 圭一; 大山 雅史; 内山 明彦

  核医学 (一社)日本核医学会 30 (8) 932 - 932 0022-7854 1993/08
• ペダリング運動おけるスキルの評価

  星川 秀利; 木村 裕一; 玉木 啓一; 藤本 浩志; 中村 好男; 村岡 功

  バイオメカニズム学会誌 バイオメカニズム学会 17 (3) 173 - 182 1993 

  The purpose of this study was to investigate the influence of training level on indices of effectiveness (IE). Six male cyclists and non cyclists performed pedalling bouts for I minute using a cycle ergometer against the work load of 1 50, 200 and 250W. The subjects were directed to maintain 90 rpm of pedalling rate during the cycling bouts. Rotary encorders and triaxis force sensors were mounted on the ergometer for measuring crank angle, both pedal forces and both pedal angles. Using these data, the resultant pedal force (FR) and the force perpendicular component of the crank force (FE) were calculated. IE represents the ratio of the force component perpendicular to the crank to the appplied force to the pedals and was calculated by FR and FE . IE was not different between cyclist and non cyclist groups. On the other hand, peak FR during 250W was significantly lower in cyclists than non cyclists ( 344.9±37.6 [N] and 398.4±24.6 [N] respectively, p<0.05). Those results suggested that pedalling skill would be reflected by the lower pedalling force which was related with a reduction of negative force during up phase rather than its efficiency converting to effective torque.
• ペダリング運動におけるスキルの評価

  星川秀利; 木村裕一; 玉木啓一; 藤本浩志; 中村好男; 村岡功

  バイオメカニズム学会誌 17 (3) 18 - 24 1993 [Refereed]
  
• Detection of Respiratory Sinus Arrhythmia by Using Adaptive Filter

  Tosiaki Yamanouchi; Akihiko Uchiyama; Yuichi Kimura; Yosio Nakamura

  Japanese journal of medical electronics and biological engineering 31 (1) 18 - 24 0021-3292 1993 [Refereed]
   

  A method for detecting respiratory sinus arrhythmia (RSA) by using an adaptive filter is proposed. RSA is a correlative component to breath which is comprised in a heart rate fluctuation. Since the spectrum of the breath changes with respiratory rate, methods that assume statistical stationarity, e.g. FFT, cannot detect RSA precisely under free breath. So we have adopted an adaptive filter which has two inputs. One is a primary input to which an interval between successive R-wave in ECG is applied. The other is a reference input to which a respiratory signal, such as chest movement or respiratory flow rate, is applied. This filter extracts correlated component to the reference signal in the primary input. A remarkable merit of an adaptive filter is a tracking capability, such as the characteristics are followed to input signal, even if power spectrum of the signal changes slowly with time. In this paper, a least mean square algorithm is used to control the filter because of its simplicity. There are two parameters to be decided for the adaptive filter. One is dimension n, and the other is convergent parameter µ. These parameters must be optimized, because they affect to tracking speed and error. A small µ causes slow tracking characteristics with small error. A large µ brings fast tracking speed with large error. As a result of simulation, we can conclude that the optimal µl is obtained by 1/(‘power of reference input’ x70x w). To test the filter characteristics, change of RSA during exercise of bicycle ergometer and that with posture characteristics were measured under free breath. The results of experiments have shown that the proposed method is effective for the estimation of RSA. © 1993, Japanese Society for Medical and Biological Engineering. All rights reserved.
• 不活性ガスを用いた心拍出量の無侵襲計測

  木村裕一

  通信学会論文誌 電子情報通信学会情報・システムソサイエティ J73-D-II (11) 1879 - 1886 0915-1923 1990 [Refereed]
  
• Power spectrum of heart rate fluctuations during incremental cycle exercise

  Yoshio Nakamura; Keiichi Tamaki; Minoru Shinohara; Yuichi Kimura; Isao Muraoka

  Japanese Journal of Physical Fitness and Sports Medicine 38 (5) 208 - 214 0039-906X 1989 [Refereed]
   

  Spectral analysis was applied to investigate whether the system for control of heart rate (HR) is influenced by exercise intensity. Five healthy males performed incremental exercise on an electrically braked cycle ergometer until exhaustion. The work rate was increased at 12 W/min following 2 min of exercise at a constant load of 20 W. HR was measured every second from R-R intervals. The power spectrum was calculated every 10 s using the FFT method for 64 consecutive data points. Power spectra during 20 W exercise showed a similar pattern to those in previous reports on resting HR perturbations. Although interindividual differences were observed for the spectrum patterns related to exercise intensity, there was a characteristic pattern revealing dissipation of the spectral power above a frequency of 0.2 Hz for all subjects. This pattern was not maintained for more than 1 min in any of the subjects, and was followed by a semirandom pattern whose magnitude varied among the subjects. These results support the hypothesis that the cardiac pacemaker is influenced by exercise intensity, presumably due to sympatho-vagal interaction with the respiratory control system. © 1989, The Japanese Society of Physical Fitness and Sports Medicine. All rights reserved.
• 漸増負荷運動中の心拍揺動パワースペクトルの推移

  中村好男; 玉木啓一; 木村裕一

  体力科学 38 (5) 208 - 214 1989 [Refereed]
  
• ペダリング運動時 の下肢関節トルクにおけるサイクリストと非サイクリストの比較

  星川秀利; 玉木啓一; 藤本浩志; 木村裕一; 斎藤浩一; 佐藤吉朗; 中村好男; 村岡功

  体力科学 48 547 - 558 [Refereed]
  

Books etc

• Multidisciplinary Computational Anatomy

  Yuichi Kimura (ContributorIntegrating Bio-metabolism and Structural Changes for the Diagnosis of Dementia)Splinger 2022/11 9789811643255 169 172
• Human Brain Imaging of Adenosine Receptors

  Masahiro Mishina; Yuichi Kimura; Kiichi Ishiwata (Joint work)Elsevier 2013
• 実践 医用画像解析ハンドブック

  木村 裕一 (Joint workPETによる分子イメージング)オーム社 2012 9784274212826 490-497
• 医用画像工学ハンドブック

  木村 裕一 (Joint workPET動態解析)日本医用画像工学会 2012 9784990666705 644-649
• PET動態解析

  木村裕一 (Single work)日本医用画像工学会 2012
• PETによる分子イメージング

  木村裕一; 坂田宗之; 坂口和也 (Joint work)オーム社 2012
• Brain Imaging Using PET

  Michio Senda; Yuichi Kimura; Peter Herscovitch (Joint editor)Academic Press 2002
• ME用語辞典

  木村 裕一 (Joint editor)コロナ社 1999 9784339070736

Conference Activities & Talks

• 夜の学校【技術】 Aβ集積, 受容体定量の理論と実際  [Invited]

  木村裕一

  PETサマーセミナー2023 in 成田  2023/08  成田市  日本核医学会PET核医学分科会
  
• アミロイドPET撮像判断のための生成系AIによるFDG画像からのアミロイド画像合成の検討  [Not invited]

  本田 実沙; 山田 誉大; 永岡 隆; 三上 勝大; 根本 充貴; 花岡 宏平; 甲斐田 勇人; 石井 一成; 木村 裕一

  第5回日本核医学会近畿地方支部会  2023/07  近畿大学東大阪キャンパス  日本核医学会関西支部
  
• Depressive Disorder Using Novel PET Tracer [11C]K--2 and AI  [Not invited]

  Sakiko Tsugawa; Yuichi Kimura; Mai Hatano; Waki Nakajima; Hiroyuki Uchida; Tomoyuki Miyazaki; Tetsu; Arisawa; Yuuki Takada; Akane Sano; Kotaro Nakano and; Tsyoshi Eiro; Akira Suda; Takeshi Asami; Akitoyo; Hishimoto; Hideaki tani; Nobuhiro Nagai; Teruki Koizumi; Shinichiro Nakajima; Shuna Kurokawa; Yohei Ohtani; Kie; Takahashi; Yuhei Kikuchi; Taisuke Tayomi; Yoji Hirano and; Ryo Mitoma; Shunsuke Tamura; ans; Shingo Baba; Osamk Togao and; Hirotaka Kisaka; Hidehiko Okazawa; Masaru Mimura; Takuya; Takahashi

  SNMMI Annual Conference  2023/06  Chicago, IL  Society of Nuclear Medicine and Molecular Imaging
  
• Chracterization of Four Major Psychiatric Disorders Based on AMPA Receptor Distributions Measured with [11C]K--2: a Novel PET Tracer Study  [Not invited]

  Mai Hatano and; Waki Nakajima; Hiroyuki Uchida; Tomoyuki Miyazaki; Tetsu; Arisawa; Yuuki Takada; Sakiko Tsugawa; Akane Sano and; Kotaro Nakano; Tsuyoshi Eiro; Hiroki Abe; Akira Suda and; Takeshi Asami; Akitoyo Hishimoto; Hideaki Tani; Nobuhito; Nagai; Teruki Koisuzmi; Shinichiro Nakajima; Sunya; Kurokawa; Yohei Ohtani; Kie Takahashi; Yuhei Kikuchi and; Taisuke yayomi; Shiori Honda; Masahiro z`Jinzaki; Yoji; Hirano; Ryu Mitoma; Shunjukta Tamura; Shingo aBaba an; Osamu Togao; Hirotaka Kisaka; Hidehiko Okazawa; Yuihi Kimura; Masaru Mimura; Takuya Takahashi

  SNMMI Annual Conference  2023/06  Chicago, IL  Society of Nuclear Medicine and Molecular Imaging
  
• 在宅人工臓器治療に応用可能な無拘束での生体情報モニタリング技術の検討  [Invited]

  木村裕一

  第60回日本人工臓器学会大会  2022/11
• 医工学領域での研究設定と進め方  [Invited]

  木村 裕一

  2022年度第5回学術教育セミナー  2022/09  大阪府臨床工学技士会
  
• CT画像のAIテクスチャ解析による体外衝撃波結石破砕術の結果予測  [Not invited]

  根本充貴; 中前有香子; 木村裕一; 出口龍良; 山下真平; 柑本康夫; 原勲

  第109回日本泌尿器科学会総会  2021/12
• ジョイントセッション 日本人工臓器学会/日本生体医工学会,在宅人工臓器治療の最前線と未来への技術開発:在宅血液透析と補助人工心臓治療日本生体医工学会における在宅人工臓器治療に向けた方針と体制  [Invited]

  木村裕一

  第59回日本人工臓器学会大会  2021/11
• 核医学会シンポジウム10 PETにおけるAI --- CycleGANを用いたPET画像合成における定量性の検討  [Invited]

  木村 裕一

  第61回日本核医学会学術集会  2021/11
• 敵対的生成ネットワークで合成したPET画像における定量性の検討  [Not invited]

  渡邉 綾; 木村 裕一; 山田 誉大; 渡辺 翔吾; 永岡 隆; 根本 充貴; 宮崎 晃一; 花岡 宏平; 甲斐田 勇人; 石井 一成

  第61回日本核医学会学術総会  2021/11
• 2種類の異常検知を用いた{FDG-PET/CT}像上のがん骨転移病変の自動検出  [Not invited]

  山口 明乃; 根本 充貴; 甲斐田 勇人; 木村 裕一; 永岡 隆; 山田 誉大; 花岡 宏平; 北島 一宏; 石井 一成

  第61回日本核医学会学術総会  2021/11
• Detection of Bone Metastases on FDG-PET/CT Images by Using Two-Step Anomaly Detection  [Not invited]

  H Yamaguchi; M Nemoto; H Kaida; Y Kimura; T Nagaoka; T Yamada; K. Hanaoka; K. Kitajima; T Tsuchitani; K Ishii

  Computer Assisted Radiology and Surgery Proceedings of the 35th International Congress and Exhibition  Munich  International Conference of Computer Assisted Radiology and Surgery
  
• 最新の医療画像診断技術 --- PETを用いた認知症・精神疾患の診断を中心に ---  [Invited]

  木村裕一

  2021センシング技術応用セミナー, ヘルスセンシングとヘルスケアの最前線 ～アフターコロナのセンシングを展望する ～, センシング技術応用研究会  2021/06
• CT画像上のテクスチャ解析によるESWL治療可能性な尿路結石の自動認識  [Not invited]

  中前 有香子; 根本 充貴; 木村 裕一; 永岡 隆 an; 山田 誉大; 出口 龍良; 山下 真平; 柑本 康夫; 原 勲

  第60回日本生体医工学会大会  2021/06  京都  日本生体医工学会
  
• 認知症診断{AI}アルゴリズム学習のための{CycleGAN}で合成した{PET}画像の定量的検証  [Not invited]

  渡邉 綾; 山田 誉大; 渡辺 翔吾; 永岡 隆; 根本 充貴; 宮崎 晃一; 花岡 宏平; 甲斐田 勇人; 石井 一成; 木村 裕一

  第60回日本生体医工学会大会  2021/06  京都  日本生体医工学会
  
• 日本人工臓器学会--日本生体医工学会合同シンポジウム: 補助人工心臓及び血液透析の在宅利用のための医工学研究 --- 在宅人工臓器治療の普及を目指して ---  [Invited]

  木村裕一; 古薗勉

  第60回日本生体医工学会大会  2021/06  京都  日本生体医工学会
  
• Integration of clinical needs and research seeds  [Invited]

  木村裕一

  第121回日本医学物理学会学術大会  2021/04
• 最新の医療画像診断技術 --- PETを用いた認知症診断を中心に ---  [Invited]

  木村裕一

  第58回センサ & アクチュエーター技術シンポジウム  2020/12  一般社団法人 次世代センサ協議会
  
• One-class SVMを用いた異常検知によるPET/CT上の骨転移病変自動検出  [Not invited]

  田中 敦子; 根本 充貴; 甲斐田 勇人; 木村 裕一; 永岡 隆; 牛房 和之; 山田 誉大; 花岡 宏平; 北島 一宏; 槌谷 達也; 石井 一成

  第60回日本核医学学術総会  2020/11
• 認知症自動診断AIアルゴリズム学習のための深層学習により加増したアミロイド画像の検証  [Not invited]

  渡邉 綾; 木村 裕一; 山田 誉大; 渡辺 翔吾; 永岡 隆; 根本 充貴; 宮崎 晃一; 花岡 宏平; 甲斐田 勇人; 石井 一成

  第60回日本核医学学術総会  2020/11
• 生体医工学での研究の進め方 --- 研究を始めるに当ってこれだけは押さえておこう ---  [Invited]

  木村 裕一

  日本生体医工学会北海道支部・北海道臨床工学技士会 共催, 第56回生体医工学研究会  2019/12
• 11C標識新規トレーサーによるAMPA受容体の定量画像化のための臨床プロトコル  [Not invited]

  木村 裕一; 山田 誉大; 波多野 真衣; 中島 和希; 宮崎 智之; 高橋 琢哉

  第59回日本核医学会学術総会  2019/11
• 認知症自動診断AIアルゴリズム学習のための深層学習によるアミロイド画像の加増手法の検討  [Not invited]

  渡邉 綾; 山田 誉大; 永岡 隆; 根本 充貴; 花岡 宏平; 甲斐田 勇人; 石井 一成; 木村 裕一

  第59回日本核医学会学術総会  2019/11
• AI異常検知に基づくPET/CT上の頸胸部病変の自動認識  [Not invited]

  田中 敦子; 根本 充貴; 甲斐田 勇人; 木村 裕一; 山田 誉大; 牛房 和之; 花岡 宏平; 北島 一宏; 槌谷 達也; 石井 一成

  第59回日本核医学会学術総会  2019/11
• 認知症自動診断AIアルゴリズム学習のための深層学習によるアミロイド画像の加増手法の検討  [Not invited]

  渡邉 綾; 山田 誉大; 永岡 隆; 根本 充貴; 花岡 宏平; 甲斐田 勇人; 石井 一成; 木村 裕一

  核医学  2019/10  (一社)日本核医学会
  
• AI異常検知に基づくPET/CT上の頸胸部病変の自動認識  [Not invited]

  田中 敦子; 根本 充貴; 甲斐田 勇人; 木村 裕一; 山田 誉大; 牛房 和之; 花岡 宏平; 北島 一宏; 槌谷 達也; 石井 一成

  核医学  2019/10  (一社)日本核医学会
  
• Application of Least-Squares Cubic Linear Regression to the Logan Graphical Analysis to Reduce the Underestimation of BPND for Neuroreceptor Parametric Imaging in Positron Emission Tomography Studies  [Not invited]

  Paulus Kapundja Shigwedha; Takahiro Yamada; Kohei Hanaoka; Kazunari Ishii; Yuichi Kimura; Yutaka Fukuoka

  生体医工学シンポジウム2019に  2019/09
• Automatic Diagnosis of Melanoma Using Hyperspectral Data and GoogLeNet  [Not invited]

  Ginji Hirano; Mitsutaka Nemoto; Yuichi Kimura; Yoshio Kiyohara; Hiroshi Koga; Naoya Yamazaki; Gustav Christensen; Atsushi Nakamura; Takayuki Sota; Takashi Nagaoka

  生体医工学シンポジウム2019に  2019/09
• Performance Improvement of Automated Melanoma Diagnosis System by Data Augmentation  [Not invited]

  Kana Kato; Mitsutaka Nemoto; Yuichi Kimura; Yoshio Kiyohara; Hiroshi Koga; Naoya Yamazaki; Gustav Christensen; Atsushi Nakamura; Takayuki Sota; Takashi Nagaoka

  生体医工学シンポジウム2019に  2019/09
• Weighting Function for Kinetics-Based Noise Reduction in PET Amyloid Imaging  [Not invited]

  Takahiro Yamada; Shogo Watanabe; Takashi Nagaoka; Mitsutaka Nemoto; Kohei Hanaoka; Hayato Kaida; Kazunari Ishii; Yuichi Kimura

  生体医工学シンポジウム2019  2019/09
• 日本核医学会核医学理工分科会特別セッション  [Invited]

  木村 裕一

  PETサマーセミナー2019  2019/08
• Custering-based data reduction algorithm with simplified reference tissue modelto generate parametric images in amyloid imaging  [Not invited]

  T.Yamad; Y. Kimura; M. Sakata; T. Nagaoka; M. Nemoto; K. Hanaoka; H. Kaida; K. Ishii

  Brain and Brain PET 2019  2019/07
• Clinical Protocol to Quantify AMPA Receptors Using Novel 11C‐labeled PET Tracer of K2  [Not invited]

  Yuichi Kimura; Takahiro Yamada; Mai Hatano; Waki Nakajima; Tomoyuki Miyazaki; Takuya Takahashi

  2019 SNMMI Annual Meeting  2019/06  Anaheim, California, USA  Society of Nuclear Medicine and Molecular Imaging
  
• 生体医工学会領域での研究の現状と展望 & 臨床研究法への取り組み  [Invited]

  木村 裕一

  兵庫県立大学先端医工学研究センター 第19回学術講演会  2019/06
• 臨床研究法: 生体医工学研究の該当性を考える  [Not invited]

  黒田 知宏; 木村 裕一

  第58回日本生体医工学会大会  2019/06
• 深層畳み込みオートエンコーダを用いた健常データの教師なし学習による 病変認識特徴量の汎用的自動生成  [Not invited]

  牛房 和之; 根本 充貴; 木村 裕一; 永岡 隆; 山田 誉大; 林 直人

  第58回日本生体医工学会大会  2019/06
• FDG-PET/CTの統計的異常検知処理による転移を考慮した頸胸部病変の自動検出病変認識特徴量の汎用的自動生成  [Not invited]

  田中 敦子; 根本 充貴; 甲斐田 勇人; 木村 裕一; 永岡 隆; 山田 誉大; 花岡 宏平; 石井 一成

  第58回日本生体医工学会大会  2019/06
• 撮像認証の流れと撮像体制の調査  [Invited]

  木村 裕一

  第19回日本核医学会春季大会  2019/04  東京  日本核医学会
  
• Deep Learning ー 基礎と核医学への応用 ー  [Invited]

  木村 裕一

  日本メジフィジックス 社内講演会  2019/03
• SRTM法を用いたアミロイドイメージングに対する空間分解能を損なわないノイズ低減アルゴリズムの検討  [Not invited]

  山田 誉大; 木村 裕一; 根本 充貴; 坂田 宗之; 永岡 隆; 花岡 宏平; 甲斐田勇人; 石井 一成

  第58回日本核医学会学術総会  2018/11
• 深層学習を用いたDatSCANにおけるパーキン症候群の画像診断  [Not invited]

  渡辺 翔吾; 杉本 直三; 木村 裕一; 根本 充貴; 山田 誉大; 石井 一成; 三品 雅洋

  第58回日本核医学会学術総会  2018/11
• AI異常検知を用いたPET/CT上の頸胸部原発性・転移性病変の検出  [Not invited]

  根本 充貴; 甲斐田 勇人; 田中 敦子; 牛房 和之; 山田 誉大; 木村 裕一; 花岡 宏平; 石井一成

  第58回日本核医学会学術総会  2018/11
• 撮像施設認証制度の概略  [Invited]

  木村 裕一

  第58回日本核医学会学術総会  2018/11  沖縄コンベンションセンター  日本核医学技術学会
  
• 11C標識新規トレーサーによるLoganグラフィカル法を用いたAMPA受容体の定量画像化  [Not invited]

  木村 裕一; 宮崎 智之; 高橋 拓磨

  第58回日本核医学会学術総会  2018/11  沖縄コンベンションセンター  日本核医学会
  
• AI異常検知を用いたFDG-PET/CT上の頸胸部原発性・転移性病変の検出  [Not invited]

  根本 充貴; 甲斐田 勇人; 田中 敦子; 牛房 和之; 山田 誉大; 木村 裕一; 花岡 宏平; 石井 一成

  核医学  2018/11  (一社)日本核医学会
  
• Deep Learning ー 基礎と核医学への応用 ー  [Invited]

  木村 裕一

  第22回Neurology SPECT定量検討会  2018/10  ステーションコンファレンス東京
• Quantitative Imaging of AMPA Receptors Using Novel 11C-labeled PET Tracer for AMPA Receptors  [Not invited]

  KIMURA Yuichi

  Annual Congress of the Europian Association of Nuclear Medicine  2018/10
• Determination of Appropriate Reconstruction Parameters for Each pf 21 PET Scanner Models from 6 Vendors to Meet the Society Phantom Criteria for Brain Amyloid PET Imaging  [Not invited]

  Yasuhiko Ikari; Keiichi Matsumoto; Goh Akamatsu; Hiroshi Nishida; Yuichi Kimura; Keiichi Oda; Michio Senda

  Annual Congress of the Europian Association of Nuclear Medicine  2018/10
• A Less-Biased Regression Method to Quantify Receptor Density from the Logan Graphical Analysis in Positron Emission Tomography  [Not invited]

  Paulus Kapundja Shigwedha; Yuichi Kimura; YUtaka Fukuoka

  IEEE EMBC18  2018/07
• PETアミロイドイメージングのための空間分解能を損なわないノイズ低減アルゴリズムの臨床画像による評価  [Not invited]

  木村 裕一山田; 誉大; 木村 裕一; 藤井 康介; 渡辺 翔吾; 永岡 隆; 根本 充貴; 花岡 宏; 甲斐田 勇人; 石井 一成

  第57回日本生体医工学会大会  2018/06
• PET施設認証セミナー --- 撮像認証の流れと撮像体制の調査  [Invited]

  木村 裕一

  2018/05
• Noise Reduction Algorithm for Amyloid Image Preserving Image Resolution --- Quantitative Evaluation Using Clinical Images  [Not invited]

  KIMURA YuichiTakahiro Yamada; Yuichi Kimura; Kosuke Fuji; Shogo Watanabe; Takashi Nagaoka; Mitsutaka Nemoto; Kohei Hanaoka; Hayato Kaida; Chisa Hosokawa; Kazunari Ishii

  Human Amyloid Imaging 2018  2018/01
• Phantom Test Procedures and Criterion for Standardization of Brain PET Imaging across Different Cameras  [Not invited]

  Go Akamatsu; Yasuhiro Ikari; Hidekatsu Wakizaka; Taiga Yamaya; Yuichi Kimura; Keiichi Oda; Michio Senda

  2017 IEEE Nuclear Science Symposium and Medical Imaging Conference  2017/10
• 機械学習によるDatSCANのPD・健常の自動鑑別  [Not invited]

  渡辺 翔吾; 木村 裕一; 根本 充貴; 山田 誉大; 藤井 康介; 林 俊行; 三品 雅洋

  第57回日本核医学会学術総会  2017/10
• 動態に基づいたアミロイドイメージング雑音除去アルゴリズムの性能評価  [Not invited]

  山田 誉大; 木村 裕一; 藤井 康介; 渡辺 翔吾; 永岡 隆; 花岡 宏平; 細川 知紗; 石井 一成; 村上 卓道

  第57回日本核医学会学術総会  2017/10
• 機械学習を用いた認知症自動鑑別におけるFDG画像とMR画像の比較  [Not invited]

  坂田 宗之; 王 小宇; 石井 賢二; 木村 裕一; 我妻 慧; 石橋 賢士; 豊原 潤; 矢田 紀子; 眞鍋 佳嗣

  第57回日本核医学会学術総会  2017/10
• 医用画像工学の応用 ー 分子イメージングと診断支援 ―  [Invited]

  木村 裕一

  第58回 日本放射線技術学会 近畿部会 学術大会  2015/01
• Qualification of PET cameras and imaging sites for 11C-methionine PET on brain tumor in Japan  [Not invited]

  Kimura Yuichi; Nishida Hiroyuki; Ikari Yasuhiko; Matsumoto Keiichi; Oda Keiichi; Nishio Tomoyuki; Fukukita Hiroyoshi; Inoue Tomio; Senda Michio

  JOURNAL OF NUCLEAR MEDICINE  2014/05
• Comparison between SUV and BP images acquired using 11C-PIB PET: Questionable PIB accumulation in SUV images  [Not invited]

  Hosokawa Chisa; Ishii Kazunari; Kimura Yuichi; Sakaguchi Kenta; Hosono Makoto; Murakami Takamichi

  JOURNAL OF NUCLEAR MEDICINE  2014/05
• 11C-PIB-PET SUV画像の視覚判定と定量評価  [Not invited]

  細川 知紗; 村上 卓道; 石井 一成; 木村 裕一; 兵頭 朋子; 細野 眞; 坂口 健太; 宇佐美 公男

  第46回日本核医学会近畿地方会  2013/07  大阪  第46回日本核医学会近畿地方会
  
• [11C]BF-227を用いた脳内アミロイド蓄積に関する動脈採血データを用いた定量解析  [Not invited]

  田代学; 岡村信行; 熊谷和明; 古本祥三; 船木善仁; 木村裕一; 岩田錬; 工藤幸司; 渡部浩司; 荒井啓行; 谷内一彦

  核医学  2009/09  (一社)日本核医学会
  
• 新しいグラフプロット法による脳神経受容体結合能の定量解析  [Not invited]

  伊藤 浩; 横井 孝司; 生駒 洋子; 志田原 美保; 関 千江; 高橋 英彦; 高野 晴成; 木村 裕一; 須原 哲也

  核医学  2008/09  (一社)日本核医学会
  
• Formation of parametric images in positron emission tomography using a clustering-based kinetic analysis with statistical clustering  [Not invited]

  Y Kimura; Y Noshi; K Oda; K Ishii

  PROCEEDINGS OF THE 23RD ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-4  2001  IEEE
   

  A method is proposed for forming parametric images in positron emission tomography, using clustering kinetic analysis. To overcome the dual problems experienced in voxel-based data, of signal noise and the very long computational time, the data are clustered before parameter estimation, and then an estimation procedure is applied to the averaged data in eac: hcluster. Using this algorithm, PET data are optimally clustered, depending on the noise that is present, by hierarchically applying a statistical-clustering algorithm based on Mixed Gaussian model. In a computer simulation, the proposed method correctly clustered noise-contaminated data. Applying the proposed algorithm to F-18-FDG clinical data, physiologically acceptable parametric images of glucose metabolism in a brain were obtained in a practical calculation time.

Works

• 微少採血系開発及び無採血化を含むPETによるマウス神経受容体定量画像手法の構築

  2008 -2010
• 歩行アシスト装置を使用した際の，心理および運動能力に関する影響の計測および解析

  2006 -2007
• 参照領域及び動脈採血省略を伴うPET による汎用神経受容体濃度画像作成手法の構築

  2006 -2007
• 無採血,部分容積効果補正を伴うPETによるFDG糖代謝詳細画像の痴呆診断への応用

  2004 -2005
• 統計的手法によるPET定量性向上に関する研究

  2001/10 -2002/12
• 動脈採血の省略を伴う陽電子断層像パラメトリック機能画像の高信頼度・高速生成手法

  2001 -2002
• 高信頼度核医学パラメトリック画像の高速生成手法に関する研究

  1998 -1999
• 核医学機能画像の高速生成手法に関する研究

  1997

MISC

• Survey for understanding the actual impact of the clinical trials act on medical device development researches

  黒田知宏; 杉町勝; 木村裕一; 大城理; 村垣義浩; 佐久間一郎; 鈴木孝司; 鎮西清行; 吉元俊輔; 櫻井理紗; 中村英夫  日本生体医工学会大会プログラム・抄録集(Web)  61st-  2022
• 画素異常検知と深層教師なし特徴抽出によるFDG-PET/CT像上がん骨転移検出

  山口明乃; 根本充貴; 甲斐田勇人; 甲斐田勇人; 木村裕一; 永岡隆; 山田誉大; 花岡宏平; 北島一宏; 槌谷達也; 石井一成; 石井一成  日本生体医工学会大会プログラム・抄録集(Web)  61st-  2022
• 深層画像生成技術を用いたFDG-PET/CT像異常検知による病変強調

  瀬川新; 根本充貴; 甲斐田勇人; 甲斐田勇人; 山口明乃; 木村裕一; 永岡隆; 山田誉大; 北島一宏; 石井一成; 石井一成  日本生体医工学会大会プログラム・抄録集(Web)  61st-  2022
• 深層学習によるメラノーマの自動診断-HSDの主成分分析による次元縮約-

  金澤祐斗; 永岡隆; 木村裕一; 根本充貴  電子情報通信学会技術研究報告(Web)  120-  (431(MI2020 47-97))  2021
• Quantitative validation on PET image generator using CycleGAN for CAD to dementia

  渡邉綾; 山田誉大; 渡辺翔吾; 永岡隆; 根本充貴; 宮崎晃一; 花岡宏平; 甲斐田勇人; 甲斐田勇人; 石井一成; 石井一成; 木村裕一  日本生体医工学会大会プログラム・抄録集(Web)  60th-  2021
• Detection of bone metastasis on FDG-PET / CT image using cascade by two types of anomaly detections

  山口明乃; 根本充貴; 甲斐田勇人; 甲斐田勇人; 木村裕一; 永岡隆; 山田誉大; 花岡宏平; 北島一宏; 槌谷達也; 石井一成; 石井一成  日本生体医工学会大会プログラム・抄録集(Web)  60th-  2021
• 2種類の異常検知を用いたFDG-PET/CT像上のがん骨転移病変自動検出

  山口明乃; 根本充貴; 甲斐田勇人; 甲斐田勇人; 木村裕一; 永岡隆; 山田誉大; 花岡宏平; 北島一宏; 槌谷達也; 石井一成; 石井一成  核医学(Web)  58-  (Supplement)  2021
• 敵対的生成ネットワークで合成したPET画像における定量性の検討

  渡邉綾; 木村裕一; 山田誉大; 渡辺翔吾; 永岡隆; 根本充貴; 宮崎晃一; 花岡宏平; 甲斐田勇人; 甲斐田勇人; 石井一成; 石井一成  核医学(Web)  58-  (Supplement)  2021
• Development of KindAI-COVID, a diagnostic support system for COVID pneumonia using CT images

  永岡隆; 小塚健倫; 根本充貴; 波部斉; 山田誉大; 吉田久; 木村裕一; 石井一成; 石井一成  日本生体医工学会大会プログラム・抄録集(Web)  60th-  2021
• Special Issue on Guideline for Deciding the Applicability of the Clinical Trials Act and Researches in Biomedical Engineering

  KIMURA Yuichi; KURODA Tomohiro  Transactions of Japanese Society for Medical and Biological Engineering  58-  (4-5)  134  -134  2020/10  [Invited]
  
• Automatic detection of cervical and thoracic lesions on FDG-PET/CT by organ specific one-class SVMs

  A. Tanaka; M. Nemoto; H. Kaida; Y. Kimura; T. Nagaoka; T. Yamada; K. Ushifusa; K. Hanaoka; K. Kitajima; T. Tsuchitani; K. Ishii  International Journal of Computer Assisted Radiology and Surgery  15-  (S1)  208  -209  2020/06  [Refereed]
  
• 正常データセットの教師なし学習に基づく病変検出支援システム画像特徴量の汎用的生成に関する検討-少規模なデータセットを用いた特徴量生成の実験的検証-

  牛房和之; 根本充貴; 木村裕一; 永岡隆; 山田誉大; 田中敦子; 林直人  電子情報通信学会技術研究報告  119-  (399(MI2019 65-123)(Web))  2020
• One-class SVMを用いた病変強調によるFDG-PET/CT上の頸胸部病変の自動検出

  田中敦子; 根本充貴; 甲斐田勇人; 木村裕一; 永岡隆; 山田誉大; 牛房和之; 花岡宏平; 北島一宏; 槌谷達也; 石井一成; 石井一成  電子情報通信学会技術研究報告  119-  (399(MI2019 65-123)(Web))  2020
• Additional consideration of image features suitable for melanoma diagnosis

  田村侑大; 根本充貴; 木村裕一; 永岡隆  日本生体医工学会大会プログラム・抄録集(Web)  59th-  2020
• Performance of automated melanoma diagnosis by adding lesion information to deep convolutional neural network

  平野銀次; 根本充貴; 木村裕一; 永岡隆  電子情報通信学会技術研究報告(Web)  120-  (219(MICT2020 7-20))  2020
• 認知症自動診断AIアルゴリズム学習のための深層学習により加増したアミロイド画像の検証

  渡邉綾; 木村裕一; 山田誉大; 渡辺翔吾; 永岡隆; 根本充貴; 宮崎晃一; 花岡宏平; 甲斐田勇人; 甲斐田勇人; 石井一成; 石井一成  核医学(Web)  57-  (Supplement)  2020
• One-class SVMを用いた異常検知によるPET/CT上の骨転移病変自動検出

  田中敦子; 根本充貴; 甲斐田勇人; 甲斐田勇人; 木村裕一; 永岡隆; 牛房和之; 山田誉大; 花岡宏平; 北島一宏; 槌谷達也; 石井一成; 石井一成  核医学(Web)  57-  (Supplement)  2020
• A generalized generation of image feature for lesion detection by unsupervised deep learning with few cases-Experimental verification with chest CT-

  牛房和之; 根本充貴; 木村裕一; 永岡隆; 山田誉大; 田中敦子; 林直人  日本医用画像工学会大会予稿集(CD-ROM)  39th-  2020
• Deep learningを用いた非高濃度乳房に対する乳腺領域の自動抽出

  山室美佳; 山室美佳; 浅井義行; 橋本直美; 安田奈生; 尾崎吉明; 任誠雲; 石井一成; 山田誉大; 根本充貴; 木村裕一; 吉田久; 半田久志; 李鎔範  日本乳癌検診学会学術総会プログラム抄録集  30th (CD-ROM)-  2020
• 生体医工学300号に寄せて

  木村 裕一  生体医工学  57-  (4/5)  97  -97  2019/11  [Invited]
  
• 11C標識新規トレーサーによるAMPA受容体の定量画像化のための臨床プロトコル

  木村 裕一; 山田 誉大; 波多野 真衣; 中島 和希; 宮崎 智之; 高橋 琢哉  核医学  56-  (Suppl.)  S162  -S162  2019/10
• 認知症自動診断AIアルゴリズム学習のための深層学習によるアミロイド画像の加増手法の検討

  渡邉 綾; 山田 誉大; 永岡 隆; 根本 充貴; 花岡 宏平; 甲斐田 勇人; 石井 一成; 木村 裕一  核医学  56-  (Suppl.)  S178  -S178  2019/10  [Refereed]
  
• A pilot study to classify multiple anatomical landmarks in CT by deep convolutional neural network.

  Nemoto M; Yamato Y; Kimura Y; Hanaoka S; Hayashi N  International Journal of Computer Assisted Radiology and Surgery  14-  (S1)  21  -22  2019/06  [Refereed]
  
• Evaluation of Robustness in Computer-Aided Diagnosis for Parkinsonian Syndromes Based on Machine Learning with Multi-center DaTSCAN SPECT Images

  渡辺 翔吾; 杉本 直三; 木村 裕一; 根本 充貴; 石井 一成; 三品 雅洋  システム制御情報学会研究発表講演会講演論文集  63-  453  -455  2019/05
• 深層畳み込みオートエンコーダを用いた健常データの教師なし学習による病変認識特徴量の汎用的自動生成

  牛房和之; 根本充貴; 木村裕一; 永岡隆; 山田誉大; 林直人  日本生体医工学会大会プログラム・抄録集(Web)  58th-  2019
• 病変検出アルゴリズムにおける局所画像特徴量の汎用的な自動生成-健常データのみの学習による特徴量生成の検討-

  牛房和之; 根本充貴; 木村裕一; 永岡隆; 山田誉大; 林直人  日本医用画像工学会大会予稿集(CD-ROM)  38th-  2019
• 認知症自動診断AIアルゴリズム学習のための深層学習によるアミロイド画像の加増手法の検討

  渡邉綾; 山田誉大; 永岡隆; 根本充貴; 花岡宏平; 甲斐田勇人; 石井一成; 石井一成; 木村裕一  核医学(Web)  56-  (Supplement)  2019
• AI異常検知に基づくPET/CT上の頸胸部病変の自動認識

  田中敦子; 根本充貴; 甲斐田勇人; 甲斐田勇人; 木村裕一; 山田誉大; 牛房和之; 花岡宏平; 北島一宏; 槌谷達也; 石井一成; 石井一成  核医学(Web)  56-  (Supplement)  2019
• 11C標識新規トレーサーによるLoganグラフィカル法を用いたAMPA受容体の定量画像化

  木村 裕一; 宮崎 智之; 高橋 琢哉  核医学  55-  (Suppl.)  S167  -S167  2018/11
• AI異常検知を用いたFDG-PET/CT上の頸胸部原発性・転移性病変の検出

  根本 充貴; 甲斐田 勇人; 田中 敦子; 牛房 和之; 山田 誉大; 木村 裕一; 花岡 宏平; 石井 一成  核医学  55-  (Suppl.)  S196  -S196  2018/11  [Refereed]
  
• A pilot study to detect anatomical landmarks using convolutional neural network

  根本 充貴; 渡辺 翔吾; 木村 裕一; 花岡 昇平; 野村 行弘; 吉川 健啓; 林 直人  電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  117-  (518)  47  -50  2018/03
• AI異常検知を用いたFDG-PET/CT上の頸胸部原発性・転移性病変の検出

  根本充貴; 甲斐田勇人; 田中敦子; 牛房和之; 山田誉大; 木村裕一; 花岡宏平; 石井一成; 石井一成  核医学(Web)  55-  (Supplement)  2018
• SRTM法を用いたアミロイドイメージングに対する空間分解能を損なわないノイズ低減アルゴリズムの検討

  山田誉大; 木村裕一; 根本充貴; 坂田宗之; 永岡隆; 花岡宏平; 甲斐田勇人; 石井一成; 石井一成  核医学(Web)  55-  (Supplement)  2018
• 動態に基づいたアミロイドイメージング雑音除去アルゴリズムの性能評価

  山田 誉大; 木村 裕一; 藤井 康介; 渡辺 翔吾; 永岡 隆; 花岡 宏平; 細川 知紗; 石井 一成; 村上 卓道  核医学  54-  (Suppl.)  S210  -S210  2017/09
• 動態に基づいたアミロイドイメージング雑音除去アルゴリズムの性能評価

  山田 誉大; 木村 裕一; 藤井 康介; 渡辺 翔吾; 永岡 隆; 花岡 宏平; 細川 知紗; 石井 一成; 村上 卓道  核医学  54-  (Suppl.)  S210  -S210  2017/09
• 機械学習によるDatSCANのPD・健常の自動鑑別

  渡辺 翔吾; 木村 裕一; 根本 充貴; 山田 誉大; 藤井 康介; 林 俊行; 三品 雅洋  核医学  54-  (Suppl.)  S210  -S210  2017/09
• 機械学習を用いた認知症自動鑑別におけるFDG画像とMR画像の比較

  坂田 宗之; 王 小宇; 石井 賢二; 木村 裕一; 我妻 慧; 石橋 賢士; 豊原 潤; 矢田 紀子; 眞鍋 佳嗣  核医学  54-  (Suppl.)  S187  -S187  2017/09
• Comparison of FDG-PET Image and MR Image in differential dementia diagnosis using machine lerning

  WANG Xiaoyu; WANG Xiaoyu; 坂田宗之; 石井賢二; 木村裕一; 木村裕一; 我妻慧; 石橋賢士; 豊原潤; 矢田紀子; 眞鍋佳嗣  電子情報通信学会技術研究報告  116-  (393(MI2016 71-121))  2017
• 機械学習を用いた認知症自動鑑別におけるFDG画像とMR画像の比較

  坂田宗之; 王小宇; 王小宇; 石井賢二; 木村裕一; 木村裕一; 我妻慧; 石橋賢士; 豊原潤; 矢田紀子; 眞鍋佳嗣  核医学(Web)  54-  (Supplement)  2017
• Development of automated delineation algorithm of reference regions for amyloid imaging. - Considering time information and the number of clusters -

  Yamada Takahiro; Kimura Yuichi; Nagaoka Takashi; Hanaoka Kohei; Hosokawa Chisa; Ishii Kazunari  Trans. jpn. Soc. Med. Bio. Eng  55-  (4)  281  -281  2017
• 陽電子断層画像を用いた生体機能画像撮像の動向

  木村 裕一  画像電子学会誌  46-  (4)  591  -594  2017
• アミロイドβ をターゲットとしたPET を用いるアルツハイマー病画像診断における動態撮像 法の再評価

  木村 裕一  Med Image Tech  35-  (1)  35  -42  2017
• 脳FDG画像を用いた認知症鑑別診断における機械学習から得られる画像指標と認知機能との関係

  坂田 宗之; 王 小宇; 石井 賢二; 木村 裕一; 我妻 慧; 石橋 賢士; 豊原 潤; 矢田 紀子; 眞鍋 佳嗣  核医学  53-  (Suppl.)  S278  -S278  2016/10
• FDG‐PETを用いた認知症鑑別診断における画像指標と臨床指標の関係

  WANG Xiaoyu; WANG Xiaoyu; 坂田宗之; 石井賢二; 木村裕一; 木村裕一; 我妻慧; 石橋賢士; 豊原潤; 矢田紀子; 眞鍋佳嗣  電子情報通信学会大会講演論文集(CD-ROM)  2016-  (2)  ROMBUNNO.D‐16‐6  -172  2016/03
• Study of Dynamic PET Reconstruction by Low-rank Non-negative Matrix Factorization

  山田純也; 本谷秀堅; 横田達也; 坂田宗之; 木村裕一  電子情報通信学会技術研究報告  116-  (298(MI2016 62-70))  2016
• 薬剤動態に基づいたアミロイドイメージングに対する雑音低減アルゴリズム

  木村裕一; 藤井康介; 山田誉大; 細川知紗; 坂田宗之; 石井一成; 村上卓道  核医学(Web)  53-  (Supplement)  2016
• 脳FDG画像を用いた認知症鑑別診断における機械学習から得られる画像指標と認知機能との関係

  坂田宗之; 王小宇; 王小宇; 石井賢二; 木村裕一; 木村裕一; 我妻慧; 石橋賢士; 豊原潤; 矢田紀子; 眞鍋佳嗣  核医学(Web)  53-  (Supplement)  2016
• Algorithm for automated delineation of reference regions in PET amyloid imaging based on pattern recognition scheme and kinetics of administered tracer

  山田 誉大; 木村 裕一; 永岡 隆  電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  115-  (301)  55  -59  2015/11
• 脳FDG画像を用いた認知症鑑別診断における機械学習の可用性の検討

  坂田 宗之; 王 小宇; 石井 賢二; 木村 裕一; 我妻 慧; 石橋 賢士; 豊原 潤; 矢田 紀子; 石渡 喜一; 眞鍋 佳嗣  核医学  52-  (3)  278  -278  2015/09
• D-16-6 A feasibility study of machine learning for differential dementia diagnosis using FDG-PET images

  Wang Xiaoyu; Sakata Muneyuki; Ishii Kenji; Kimura Yuichi; Wagatsuma Kei; Ishibashi Kenji; Toyohara Jun; Yata Noriko; Ishiwata Kiichi; Manabe Yoshitugu  Proceedings of the IEICE General Conference  2015-  (2)  146  -146  2015/02
• Eliminations of dura maters from MR Images using probablistic atlas and graph cut technique

  宇戸真弥; 本谷秀堅; 坂田宗之; 木村裕一  電子情報通信学会技術研究報告  114-  (482(MI2014 53-118))  2015
• 腫瘍診断における陽電子断層撮影

  木村 裕一  Medical Imaging Technology  33-  (4)  153  -156  2015
• 線条件アデノシンA1およびA2A受容体とパーキンソン病の振戦・固縮の関係

  三品 雅洋; 石井 賢二; 鈴木 正彦; 橋本 昌也; 木村 裕一; 長縄 美香; 坂田 宗之; 織田 圭一; 豊原 潤; 永山 寛; 石渡 喜一; 片山 泰朗  臨床神経学  54-  (Suppl.)  S239  -S239  2014/12
• 脳FDG画像の統計比較に用いるMRI解剖学的標準化の全脳抽出の改良

  坂田 宗之; 江尻 顕浩; 石井 賢二; 木村 裕一; 織田 圭一; 豊原 潤; 矢田 紀子; 石渡 喜一; 眞鍋 佳嗣  核医学  51-  (3)  328  -328  2014/09
• Qualification of PET cameras and imaging sites for 11C-methionine PET on brain tumor in Japan

  Yuichi Kimura; Hiroyuki Nishida; Yasuhiko Ikari; Keiichi Matsumoto; Keiichi Oda; Tomoyuki Nishio; Hiroyoshi Fukukita; Tomio Inoue; Michio Senda  JOURNAL OF NUCLEAR MEDICINE  55-  2014/05
• Qualification of PET cameras and imaging sites for 11C-methionine PET on brain tumor in Japan

  Yuichi Kimura; Hiroyuki Nishida; Yasuhiko Ikari; Keiichi Matsumoto; Keiichi Oda; Tomoyuki Nishio; Hiroyoshi Fukukita; Tomio Inoue; Michio Senda  JOURNAL OF NUCLEAR MEDICINE  55-  2014/05
• Full quantification of CMRGlc of small animals with arterial blood sampling using the new system of CD-Well

  Yuichi Kimura; Takashi Yamada; Nobuya Hashizume; Masahiko Nomura; Seiichiro Ota; Keishi Kitamura; Hiroshi Toyama  JOURNAL OF NUCLEAR MEDICINE  55-  2014/05
• Comparison between SUV and BP images acquired using 11C-PIB PET: Questionable PIB accumulation in SUV images

  Chisa Hosokawa; Kazunari Ishii; Yuichi Kimura; Kenta Sakaguchi; Makoto Hosono; Takamichi Murakami  JOURNAL OF NUCLEAR MEDICINE  55-  2014/05
• Present State of PET Functional Imaging and Clinical or Investigative Applications

  Kimura Yuichi  IEICE technical report.  113-  (410)  231  -231  2014/01
• Comparison between a Renormalization Method for Linear Regression and a Bayes Method for Denoising with respect to Imoprovement of Dynamic PET Image Analysis

  KOZAWA Takahiro; HONTANI Hidekata; SAKAGUCHI Kazuya; SAKATA Muneyuki; KIMURA Yuichi  IEICE technical report.  113-  (410)  285  -290  2014/01
• Employment of MRI anatomical normalization in statistical comparison of brain FDG-PET : Improvement of the whole brain extraction and performance evaluation

  EJIRI Akihiro; SAKATA Muneyuki; ISHII Kenji; KIMURA Yuichi; ODA Keiichi; TOYOHARA Jun; YATA Noriko; ISHIWATA Kiichi; MANABE Yoshitsugu  IEICE technical report.  113-  (410)  127  -132  2014/01
• 線条体アデノシンA₁およびA_2A受容体とパーキンソン病の振戦・固縮の関係

  三品雅洋; 三品雅洋; 石井賢二; 鈴木正彦; 鈴木正彦; 橋本昌也; 橋本昌也; 木村裕一; 木村裕一; 長縄美香; 長縄美香; 坂田宗之; 織田圭一; 豊原潤; 永山寛; 石渡喜一; 片山泰朗  日本神経学会学術大会プログラム・抄録集  55th-  2014
• The prediction of blood pressure changes by the habit of walking

  Toshiyo Tammura; Soichi Maeno; Yutaka Kimira; Yuichi Kimura; Takumu Hattori; Kotaro Minato  IFMBE Proceedings  41-  1406  -1408  2014
• 未治療パーキンソン病における被殻アデノシンA1受容体密度

  三品 雅洋; 石渡 喜一; 石井 賢二; 木村 裕一; 鈴木 正彦; 橋本 昌也; 坂田 宗之; 織田 圭一; 豊原 潤; 北村 伸; 片山 泰朗  臨床神経学  53-  (12)  1435  -1435  2013/12
• Variability in PET quantitation within a multicenter studies in Japan

  K. Matsumoto; K. Suzuki; H. Fukukita; Y. Ikari; K. Oda; Y. Kimura; S. Sakamoto; N. Shimada; T. Shiraishi; T. Nishio; H. Nishida; T. Terauchi; M. Senda  EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING  40-  S305  -S305  2013/10
• 脳FDG画像の統計比較を用いた認知症診断におけるMRI解剖学的標準化の導入による性能向上

  坂田 宗之; 水野 僚介; 石井 賢二; 織田 圭一; 豊原 潤; 石渡 喜一; 木村 裕一  核医学  50-  (3)  S180  -S180  2013/09
• パーキンソン病の振戦・固縮とドパミントランスポータ・ドパミンD2受容体・アデノシンA2A受容体の関係

  三品 雅洋; 石井 賢二; 鈴木 正彦; 橋本 昌也; 木村 裕一; 長縄 美香; 坂田 宗之; 織田 圭一; 豊原 潤; 片山 泰朗; 石渡 喜一  核医学  50-  (3)  S241  -S241  2013/09
• Relation of striatal density of adenosine A(2A) receptors, dopamine transporter and dopamine D-2 receptor with tremor at rest and rigidity in Parkinson's disease

  M. Mishina; K. Ishii; M. Suzuki; H. Nagayama; S. Kitamura; M. Hashimoto; M. Naganawa; Y. Kimura; M. Sakata; K. Oda; J. Toyohara; Y. Katayama; K. Ishiwata  MOVEMENT DISORDERS  28-  S52  -S53  2013/06
• Influence of rate constants as the prior to performance of denoising tissue time activity curves for PET kinetic analysis

  KOZAWA Takahiro; HONTANI Hidekata; SAKAGUCHI Kazuya; SAKATA Muneyuki; KIMURA Yuichi  IEICE technical report.  112-  (411)  287  -292  2013/01
• Performance improvements using MRI anatomical normalization in statistical comparison of brain FDG-PET for dementia diagnosis

  MIZUNO RYOSUKE; MIZUNO RYOSUKE; SAKATA MUNEYUKI; ISHII KENJI; ODA KEIICHI; TOYOHARA JUN; ISHIWATA KIICHI; KIMURA YUICHI; KIMURA YUICHI; KIMURA YUICHI  電子情報通信学会技術研究報告  112-  (411(MI2012 62-124))  25  -29  2013/01
• 未治療パーキンソン病における被殻アデノシンA1受容体密度

  三品雅洋; 三品雅洋; 石渡喜一; 石井賢二; 木村裕一; 木村裕一; 鈴木正彦; 鈴木正彦; 橋本昌也; 橋本昌也; 坂田宗之; 織田圭一; 豊原潤; 北村伸; 北村伸; 片山泰朗  日本神経学会学術大会プログラム・抄録集  54th-  317  2013
• 論文

  木村 裕一  生体医工学  51-  (6)  418  2013
• 論文の書き方講座 --- 生体医工学分野でアクセプトされる論文を書くには

  木村裕一; 堀江亮太  生体医工学  51-  (6)  51  -57  2013
• がんFDG-PET/CT撮像法ガイドライン 第2版

  福喜多 博義; 織田 圭一; 白石 貴博; 鈴木 一史; 西田 広行; 松本 圭一; 寺内 隆司; 坂本 攝; 西尾 知之; 井狩 彌彦; 千田 道雄; 木村 裕一  核医学技術  33-  377  -420  2013  [Refereed]
  
• ジスキネジアを呈するパーキンソン病では被殻アデノシンA2A受容体は増加する

  三品 雅洋; 石渡 喜一; 石井 賢二; 北村 伸; 長縄 美香; 木村 裕一; 鈴木 正彦; 橋本 昌也; 石橋 賢士; 坂田 宗之; 織田 圭一; 豊原 潤; 濱本 真; 小林 士郎; 片山 泰朗  臨床神経学  52-  (12)  1551  -1551  2012/12
• ジスキネジアを呈するパーキンソン病における被殻アデノシンA2A受容体密度 [11C]TMSX PETを用いた検討

  三品 雅洋; 鈴木 正彦; 石井 賢二; 北村 伸; 長縄 美香; 木村 裕一; 橋本 昌也; 坂田 宗之; 織田 圭一; 豊原 潤; 小林 士郎; 片山 泰朗; 石渡 喜一  脳循環代謝  24-  (1)  171  -171  2012/11
• [11C]MPDX PETを用いた未治療パーキンソン病における被殻アデノシンA1受容体結合能

  三品 雅洋; 石井 賢二; 鈴木 正彦; 北村 伸; 橋本 昌也; 木村 裕一; 坂田 宗之; 織田 圭一; 豊原 潤; 片山 泰朗; 石渡 喜一  核医学  49-  (3)  S217  -S217  2012/08
• Bayesian Inference Approach to Visualize Neuroreceptor Density using Positron Emission Tomography without Arterial Blood Sampling

  KOZAWA Takahiro; HONTANI Hidekata; SAKAGUCHI Kazuya; SAKATA Muneyuki; KIMURA Yuichi  IEICE technical report.  112-  (142)  29  -34  2012/07
• Evaluation of putaminal adenosine A(1) receptors in drug naive Parkinson's disease measured with [C-11]MPDX PET

  M. Mishina; K. Ishii; M. Suzuki; S. Kitamura; M. Hashimoto; Y. Kimura; M. Sakata; K. Oda; J. Toyohara; S. Kobayashi; Y. Katayama; K. Ishiwata  MOVEMENT DISORDERS  27-  S248  -S248  2012/06
• Validation of Spatio-temporal Reconstruction Algorithm Based on DRAMA Using Small Animal Dynamic PET Data

  KON Tatsuya; OBI Takashi; OHYAMA Nagaaki; KIMURA Yuichi  IEICE technical report.  111-  (389)  431  -435  2012/01
• Bayesian Approach for the Denoising to PET Dynamic Data without Arterial Blood Sampling

  KOZAWA Takahiro; HONTANI Hidekata; SAKAGUCHI Kazuya; SAKATA Muneyuki; KIMURA Yuichi  IEICE technical report.  111-  (389)  11  -16  2012/01
• MAP推定によるPET動態データの雑音除去法を用いた神経受容体定量画像の作成

  木村裕一; 小澤幸弘; 坂口和也; 坂田宗之; 本谷秀堅  核医学  49-  (3)  2012
• 直交展開と線形最小二乗法を用いたコンパートメントモデル推定アルゴリズム

  坂口和也; 坂田宗之; 五味勉; 梅田徳男; 木村裕一; 木村裕一  核医学  49-  (3)  2012
• 被殻アデノシンA1受容体分布の加齢変化 [11C]MPDX PETを用いた検討

  三品 雅洋; 石渡 喜一; 木村 裕一; 坂田 宗之; 織田 圭一; 石井 賢二; 片山 泰朗  脳循環代謝  23-  (1)  114  -114  2011/11
• MAP推定法によるPET動態データの雑音除去アルゴリズム

  木村 裕一; 本谷 秀堅; 坂口 和也; 織田 圭一; 石井 賢二; 坂田 宗之; 石渡 喜一  核医学  48-  (3)  S265  -S265  2011/09
• 統合失調症患者における脳シグマ-1受容体のPETによる測定

  石川 雅智; 坂田 宗之; 石井 賢二; 織田 圭一; 呉 勁; 豊原 潤; 木村 裕一; 伊豫 雅臣; 石渡 喜一; 橋本 謙二  精神薬療研究年報  (43)  57  -58  2011/03
• MAP-Based Denoising of Dynamic PET Data for Quantitative Receptor Imaging

  N. Hoshino; H. Hontani; K. Sakaguchi; M. Sakata; K. Ishiwata; Y. Kimura  SPIE Medical Imaging Conference  2011/02  [Refereed]
  
• PET脳神経受容体画像化における最尤推定を用いたグラフィカル解析法の改良

  志田原美保; 関千江; 長縄美香; 坂田宗之; 石川雅智; 伊藤浩; 菅野巌; 石渡喜一; 木村裕一  東北医学雑誌  123-  (1)  2011
• PET神経受容体濃度画像作成のための直交展開を用いた総分布容積推定法

  坂口和也; 坂田宗之; 五味勉; 梅田徳男; 木村裕一; 木村裕一  核医学  48-  (3)  2011
• 被殻アデノシンA1受容体分布の加齢変化 [C-11]MPDX PETを用いた検討

  三品 雅洋; 石井 賢二; 木村 裕一; 坂田 宗之; 織田 圭一; 小林 士郎; 片山 泰朗; 石渡 喜一  臨床神経学  50-  (12)  1183  -1183  2010/12
• Estimation algorithm using direct search method in PET neuroreceptor quantification

  OKANISHI Yosuke; KIMURA Yuichi; SUGA Mikio  IEICE technical report  109-  (407)  53  -56  2010/01
• Determination of starting time for graphical analysis using X-square test in PET receptor imaging

  OGAKI Hiroto; SAKAGUCHI Kazuya; SUGA Mikio; KIMURA Yuichi  IEICE technical report  109-  (407)  1  -6  2010/01
• A Strategy to Improve PET Neuroreceptor Analysis MA1 Based on Statistics of Measurement Errors

  HOSHINO Naoki; HONTANI Hidekata; NAGANAWA Mika; SAKAGUCHI Kazuya; SAKATA Muneyuki; ISHIWATA Kiichi; KIMURA Yuichi  IEICE technical report  109-  (407)  7  -12  2010/01
• 小動物における定量的画像解析

  外山宏; 籏野健太郎; 鈴木弘美; 工藤元; 野村昌彦; 山田貴司; 木村裕一; 市瀬正則; 澤田誠  脳循環代謝  25-  (2)  50  -57  2010
• 研究領域から日常診療におけるPETイメージ ングの精度管理

  大崎洋充; 島田直毅; 福喜多博義; 木村裕一; 千田道雄  日本放射線技術学会雑誌  68-  (7)  50  -57  2010
• Error analysis of dopamine D-2 receptor occupancy study with agonist ligand [C-11]MNPA

  M. Shidahara; H. Ito; T. Otsuka; Y. Ikoma; C. Seki; F. Kodaka; R. Arakawa; H. Takano; H. Takahashi; Y. Kimura; I. Kanno; T. Suhara  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM  29-  S347  -S347  2009/10
• Unbiased logan graphical analysis using the renormalization method

  H. Hontani; N. Hoshino; M. Naganawa; K. Sakaguchi; M. Sakata; K. Ishiwata; Y. Kimura  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM  29-  S316  -S317  2009/10
• Kinetic analysis of a novel radioligand for alpha 7 nicotinic acetylcholine receptor, [C-11]CHIBA-1001 in human brain

  M. Sakata; Y. Kimura; M. Ishikawa; J. Toyohara; J. Wu; K. Oda; K. Ishii; K. Hashimoto; K. Ishiwata  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM  29-  S371  -S372  2009/10
• Simplified quantification of adenosine A(1) receptor with [C-11]MPDX and graphical analysis

  Y. Kimura; M. Naganawa; M. Mishina; M. Sakata; K. Oda; K. Ishii; K. Ishiwata  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM  29-  S326  -S326  2009/10
• A noise reduction method for graphical analyses with KL-expansion during transient equilibrium condition

  K. Sakaguchi; M. Naganawa; M. Sakata; M. Shidahara; C. Seki; K. Ishiwata; Y. Kimura  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM  29-  S333  -S333  2009/10
• Simplified quantification of adenosine A(2A) receptor with [C-11]TMSX PET and graphical analyses

  M. Naganawa; M. Mishina; M. Sakata; K. Oda; K. Ishii; K. Ishiwata; Y. Kimura  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM  29-  S321  -S322  2009/10
• アミロイド前駆体蛋白遺伝子導入マウスにおける11C-PIB脳内結合の定量

  関 千江; 徳永 正希; 服部 聡子; 志田原 美保; 中尾 隆士; 岡内 隆; 前田 純; 樋口 真人; 木村 裕一; 須原 哲也  核医学  46-  (3)  262  -262  2009/09
• 3D-PETにおける体幹部用シールドの効果 ファントム実験による検討

  織田 圭一; 坂田 宗之; 石井 賢二; 長縄 美香; 木村 裕一; 石渡 喜一  核医学  46-  (3)  250  -250  2009/09
• アミロイド蓄積は変性の原因か結果か? 非アルツハイマー病変性型認知症における経時観察

  石井 賢二; 織田 圭一; 坂田 宗之; 木村 裕一; 石橋 賢士; 金丸 和富; 村山 繁雄; 石渡 喜一  核医学  46-  (3)  262  -262  2009/09
• PETによる瀰慢性軸索損傷時の高次脳機能障害病態の探求

  成相 直; 尤 郁偉; 日浦 幹夫; 木村 裕一; 石井 賢二; 石渡 喜一; 大野 喜久郎  核医学  46-  (3)  306  -306  2009/09
• Logan法における主成分分析を用いた雑音低減処理の評価

  坂口和也; 長縄美香; 坂田宗之; 志田原美保; 関千江; 石渡喜一; 木村裕一  核医学  46-  (3)  2009
• Aging effect on adenosine A(2A) receptors in putamen - A C-11-TMSX PET study

  M. Mishina; K. Ishiwata; K. Ishii; M. Naganawa; Y. Kimura; M. Sakata; K. Oda; K. Ishibashi; M. Suzuki; S. Kobayashi; Y. Katayama  MOVEMENT DISORDERS  24-  S202  -S202  2009
• 特集II. 医用放射線利用の最近の動向 放射線による先端生体画像計測技術 --- 陽電子断層装置 による生体機能の画像化 ---

  木村 裕一  電気評論  94-  (1)  35  -38  2009
• PET における神経受容体機能計測のための動態解析

  坂口和也; 木村裕一  Medical Imaging Technology  27-  (5)  286  -291  2009
• PETアミロイドプローベ[11C]PIB及び[11C]BF227の比較検討

  橋本 昌也; 石井 賢二; 木村 裕一; 織田 圭一; 川崎 敬一; 石川 雅智; 石渡 喜一; 岡村 信行; 谷内 一彦  臨床神経学  48-  (12)  1094  -1094  2008/12
• 未治療パーキンソン病におけるアデノシンA2A受容体の治療開始後の変化

  三品 雅洋; 石渡 喜一; 石井 賢二; 北村 伸; 木村 裕一; 長縄 美香; 織田 圭一; 橋本 昌也; 鈴木 正彦; 濱本 真; 小林 士郎; 片山 泰朗  臨床神経学  48-  (12)  1135  -1135  2008/12
• Determination of starting point for Logan graphical analysis using run test to improve PET neuroreceptor quantification

  OGAKI Hiroto; KIMURA Yuichi; NAGANAWA Mika; SAKATA Muneyuki; SHIDAHARA Miho; SUGA Mikio  IEICE technical report  108-  (209)  27  -31  2008/09
• 入力関数を用いたマウス脳内の11C-PIB動態の定量解析

  関 千江; 徳永 正希; 服部 聡子; 志田原 美保; 中尾 隆士; 外山 宏; 樋口 真人; 木村 裕一  核医学  45-  (3)  S247  -S247  2008/09
• アルツハイマー病における[11C]PIB集積の意義 代謝低下・萎縮・罹病期間との相関

  石井 賢二; 織田 圭一; 川崎 敬一; 木村 裕一; 坂田 宗之; 石川 雅智; 石橋 賢士; 金丸 和富; 村山 繁雄; 石渡 喜一  核医学  45-  (3)  S180  -S180  2008/09
• アミロイド蓄積は前頭側頭型認知症の臨床像を修飾するか?

  石井 賢二; 織田 圭一; 川崎 敬一; 木村 裕一; 坂田 宗之; 石川 雅智; 石橋 賢士; 金丸 和富; 村山 繁雄; 石渡 喜一  核医学  45-  (3)  S181  -S182  2008/09
• アミロイドプローベ[11C]PIBと[11C]BF-227の直接比較 FDGとVBMとの相関

  石井 賢二; 橋本 昌也; 木村 裕一; 織田 圭一; 坂田 宗之; 川崎 敬一; 石橋 賢士; 石川 雅智; 石渡 喜一; 岡村 信行; 谷内 一彦  核医学  45-  (3)  S182  -S182  2008/09
• パーキンソン病における抗パーキンソン病薬投与後のアデノシンA2A受容体分布の変化

  三品 雅洋; 石井 賢二; 北村 伸; 木村 裕一; 長縄 美香; 橋本 昌也; 織田 圭一; 鈴木 正彦; 小林 士郎; 片山 泰朗; 石渡 喜一  核医学  45-  (3)  S183  -S183  2008/09
• ニコチンα7受容体新規リガンド[11C]CHIBA-1001の健常者におけるPET撮影

  石川 雅智; 石井 賢二; 豊原 潤; 呉 勁; 坂田 宗之; 木村 裕一; 織田 圭一; 伊豫 雅臣; 石渡 喜一; 橋本 謙二  核医学  45-  (3)  S197  -S197  2008/09
• α7ニコチン受容体リガンド[11C]CHIBA-1001のヒト脳動態解析

  坂田 宗之; 木村 裕一; 石川 雅智; 豊原 潤; 呉 勁; 織田 圭一; 石井 賢二; 橋本 謙二; 石渡 喜一  核医学  45-  (3)  S228  -S228  2008/09
• [11C]PIBの定量解析における血漿中代謝物分析の影響

  長縄 美香; 木村 裕一; 坂田 宗之; 織田 圭一; 石井 賢二; 石渡 喜一  核医学  45-  (3)  S236  -S236  2008/09
• PET脳神経受容体画像化におけるMAP推定を用いたグラフィカル解析法の提案

  志田原美保; 関千江; 長縄美香; 坂田宗之; 石川雅智; 菅野巖; 石渡喜一; 木村裕一  日本生体医工学会大会プログラム・論文集(CD-ROM)  47th-  2008
• PET脳神経受容体画像化におけるMAP推定を用いたグラフィカル解析法の提案

  志田原美保; 関千江; 長縄美香; 坂田宗之; 石川雅智; 菅野巌; 石渡喜一; 木村裕一  核医学  45-  (3)  2008
• 連検定によるLogan法における開始時刻の決定

  木村裕一; 大柿宏人; 大柿宏人; 長縄美香; 志田原美保; 坂田宗之; 石渡喜一; 菅幹生  核医学  45-  (3)  2008
• Variations in adenosine A(2A) receptors following anti-Parkinsonian therapy in drug naive Parkinson's disease using (11)C-TMSX PET

  M. Hishina; K. Ishii; S. Kitamura; Y. Kimura; M. Naganawa; M. Hashimoto; M. Suzuki; K. Oda; M. Hamamoto; S. Kobayashi; Y. Katayama; K. Ishiwata  MOVEMENT DISORDERS  23-  (1)  S68  -S68  2008
• Reduction of noise-induced underestimation in Logan graphical analysis using scale invariant linear estimation

  Muneyuki Sakata; Y. Kimura; M. Naganawa; M. Shidahara; C. Seki; K. Oda; K. Ishii; K. Ishiwata  NEUROIMAGE  41-  T82  -T82  2008
• Parametric Imaging of the total volume of distrihution using MAP estimation for logan graphical analysis

  Miho Shidahara; Y. Kimura; C. Seki; M. Naganawa; M. Sakata; M. Ishikawa; H. Ito; T. Suhara; K. Ishiwata; I. Kanno  NEUROIMAGE  41-  T83  -T83  2008
• PET kinetic analysis: error consideration of quantitative analysis in dynamic studies

  Yoko Ikoma; Hiroshi Watabe; Miho Shidahara; Mika Naganawa; Yuichi Kimura  ANNALS OF NUCLEAR MEDICINE  22-  (1)  1  -11  2008/01  [Refereed]
  
• 未治療パーキンソン病におけるアデノシンA2A受容体とドパミントランスポータの左右差

  三品 雅洋; 石渡 喜一; 石井 賢二; 北村 伸; 木村 裕一; 長縄 美香; 織田 圭一; 橋本 昌也; 鈴木 雅彦; 小林 士郎; 片山 泰朗  臨床神経学  47-  (12)  1017  -1017  2007/12
• アミロイドプローブPIBとFDG-PETによる認知症の早期鑑別診断

  石井 賢二; 橋本 昌也; 石渡 喜一; 木村 裕一; 織田 圭一; 齊藤 祐子; 徳丸 阿耶; 金丸 和富; 村山 繁雄  臨床神経学  47-  (12)  1141  -1141  2007/12
• Lewy小体型認知症における後頭葉の機能低下に関連する遠隔部位の機能亢進

  橋本 昌也; 川崎 敬一; 鈴木 正彦; 井上 聖啓; 三谷 和子; 金丸 和富; 村山 繁雄; 織田 圭一; 木村 裕一; 石渡 喜一; 石井 賢二  臨床神経学  47-  (12)  1154  -1154  2007/12
• 認知症診断におけるPIB-PETの意義 Voxel Based Morphometryとの比較

  石井 賢二; 橋本 昌也; 木村 裕一; 石川 雅智; 織田 圭一; 川崎 敬一; 齊藤 祐子; 金丸 和富; 徳丸 阿耶; 村山 繁雄; 石渡 喜一  核医学  44-  (3)  300  -300  2007/10
• 認知症診断におけるPIB-PETの意義 FDG-PETとの比較

  石井 賢二; 橋本 昌也; 木村 裕一; 石川 雅智; 織田 圭一; 川崎 敬一; 齊藤 祐子; 金丸 和富; 徳丸 阿耶; 村山 繁雄; 石渡 喜一  核医学  44-  (3)  300  -300  2007/10
• アルツハイマー病脳におけるアミロイドプローベ[11C]PIB及び[11C]BF227の比較検討

  橋本 昌也; 石井 賢二; 木村 裕一; 織田 圭一; 川崎 敬一; 石川 雅智; 石渡 喜一; 岡村 信行; 谷内 一彦  核医学  44-  (3)  301  -301  2007/10
• 悪性神経膠腫の硼素中性子捕捉療法計画に際してのPETアミノ酸イメージの応用

  成相 直; 石渡 喜一; 木村 裕一; 稲次 基希; 百瀬 俊也; 石井 賢二; 大野 喜久郎  核医学  44-  (3)  309  -309  2007/10
• [11C]TMSX PETを用いた被殻アデノシンA2A受容体分布の加齢変化の検討

  三品 雅洋; 石井 賢二; 木村 裕一; 長縄 美香; 織田 圭一; 橋本 昌也; 鈴木 正彦; 小林 士郎; 片山 泰朗; 石渡 喜一  核医学  44-  (3)  314  -314  2007/10
• 11C-Verapamil P糖タンパク機能画像化に対するクラスタリング動態法の適用

  木村 裕一; 長縄 美香; 志田原 美保; 関 千江; 織田 圭一; 石井 賢二; 石渡 喜一  核医学  44-  (3)  314  -314  2007/10
• [11C]SA4503-PETによるシグマ1受容体動態解析における撮影時間の短縮

  坂田 宗之; 木村 裕一; 長縄 美香; 石川 雅智; 織田 圭一; 石井 賢二; 橋本 謙二; 千原 國宏; 石渡 喜一  核医学  44-  (3)  314  -314  2007/10
• ドネペジルによるシグマ1受容体の占拠 [11C]SA4503-PETを用いて

  石川 雅智; 石井 賢二; 木村 裕一; 坂田 宗之; 織田 圭一; 伊豫 雅臣; 橋本 謙二; 石渡 喜一  核医学  44-  (3)  323  -323  2007/10
• microPET Focus220を用いたサルPET検査における吸収補正に関する検討

  志田原美保; 寅松千枝; 岡内隆; 関千江; 長縄美香; 永井裕司; 伊藤浩; 大林茂; 木村裕一; 菅野巖  核医学  44-  (3)  315  -315  2007/10
• PET kinetic analysis: wavelet denoising of dynamic PET data with application to parametric imaging

  Miho Shidahara; Yoko Ikoma; Jeff Kershaw; Yuichi Kimura; Mika Naganawa; Hiroshi Watabe  ANNALS OF NUCLEAR MEDICINE  21-  (7)  379  -386  2007/09  [Refereed]
  
• Consensus nomenclature for in vivo imaging of reversibly binding radioligands

  Robert B. Innis; Vincent J. Cunningham; Jacques Delforge; Masahiro Fujita; Albert Giedde; Roger N. Gunn; James Holden; Sylvain Houle; Sung-Cheng Huang; Masanori Ichise; Hidehiro Lida; Hiroshi Ito; Yuichi Kimura; Robert A. Koeppe; Gitte M. Knudsen; Juhani Knuuti; Adriaan A. Lammertsma; Marc Laruelle; Jean Logan; Ralph Paul Maguire; Mark A. Mintun; Evan D. Morris'o; Ramin Parsey; Julie C. Price; Mark Slifstein; Vesna Sossi; Tetsuya Suhara; John R. Votaw; Dean F. Wong; Richard E. Carson  JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM  27-  (9)  1533  -1539  2007/09  [Refereed]
  
• 長時間歩行時の下肢筋の活動状態 [18F]fluorodeoxyglucoseを用いたPositron Emission Tomographyによる検討

  島田 裕之; 平田 崇; 古名 丈人; 及川 清; 木村 裕一; 杉浦 美穂; 石渡 喜一; 鈴木 隆雄  理学療法学  34-  (Suppl.2)  260  -260  2007/04
• PET tracers for mapping adenosine receptors as probes for diagnosis of CNS disorders

  Kiichi Ishiwata; Yuichi Kimura; Erik F. J. De Vries; Philip H. Elsinga  Central Nervous System Agents in Medicinal Chemistry  7-  (1)  57  -77  2007/03
• Omission of serial arterial blood sampling for quantitative analysis of monkey PET data using independent component analysis-based method

  Mika Naganawa; Hideo Tsukada; Hiroyuki Ohba; Kiichi Ishiwata; Chie Seki; Miho Shidahara; Yuichi Kimura  IEEE Nuclear Science Symposium Conference Record  6-  4510  -4512  2007  [Refereed]
  
• Inter-crystal scatter identification for a depth-sensitive detector using multi-anode outputs

  Eiji Yoshida; Keishi Kitamura; Yuichi Kimura; Fumihiko Nishikido; Kengo Shibuya; Taiga Yamaya; Hideo Murayama  IEEE Nuclear Science Symposium Conference Record  3-  1860  -1864  2007  [Refereed]
  
• Omission of serial arterial blood sampling for quantitative analysis of monkey PET data using independent component analysis-based method

  Mika Naganawa; Hideo Tsukada; Hiroyuki Ohba; Kiichi Ishiwata; Chie Seki; Miho Shidahara; Yuichi Kimura  2007 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-11  4510  -+  2007  [Refereed]
  
• PET分子イメージングにおける画像解析の問題点と現状

  木村 裕一  放射線医学  50-  (12)  16  -18  2007
• PET kinetic analysis - Pitfalls and a solution for the Logan plot

  Yuichi Kimura; Mika Naganawa; Miho Shidahara; Yoko Ikoma; Hiroshi Watabe  ANNALS OF NUCLEAR MEDICINE  21-  (1)  1  -8  2007/01  [Refereed]
  
• 多系統萎縮症における黒質線条体ドパミン機能障害の検討

  橋本 昌也; 川崎 敬一; 鈴木 正彦; 井上 聖啓; 三谷 和子; 三品 雅洋; 織田 圭一; 木村 裕一; 石渡 喜一; 石井 賢二  臨床神経学  46-  (12)  1145  -1145  2006/12
• Partial Volume Correction in PET with Projection Onto Convex Sets : The Comparison of Estimated Result Affected by Convex Sets Combination

  CHIYODA Shigeo; NAGANAWA Mika; TOGAWA Tatsuo; KIMURA Yuichi  IEICE technical report  106-  (343)  19  -23  2006/11
• Omission of arterial blood sampling in PET neuroreceptor mapping using intersectional searching method : Improvement of the blood curve estimation using the selection of voxels base on singular values and the clustering

  YANO Junichi; NAGANAWA Mika; YANAGISAWA Masao; KIMURA Yuichi  IEICE technical report  106-  (343)  13  -18  2006/11
• PET kinetic analysis - compartmental model

  Hiroshi Watabe; Yoko Ikoma; Yuichi Kimura; Mika Naganawa; Miho Shidahara  ANNALS OF NUCLEAR MEDICINE  20-  (9)  583  -588  2006/11  [Refereed]
  
• Mutual information法による脳FDG-PETのエミッションとトランスミッションのレジストレーション

  織田 圭一; 石井 賢二; 木村 裕一; 松本 和徳; 福士 政広  核医学  43-  (3)  210  -210  2006/10
• 半盲患者の中枢性ベンゾジアゼピン受容体とアデノシンA1受容体の密度

  鈴木 幸久; 成相 直; 堀江 長春; 石井 賢二; 織田 圭一; 木村 裕一; 石渡 喜一  核医学  43-  (3)  213  -213  2006/10
• 複数のPETアミノ酸プローブを用いた悪性脳腫瘍の集学的治療

  成相 直; 石渡 喜一; 百瀬 俊哉; 稲次 基希; 細田 千尋; 木村 裕一; 織田 圭一; 石井 賢二; 岩田 錬; 大野 喜久郎  核医学  43-  (3)  216  -216  2006/10
• 同時計数検出器型放射能連続モニタによる動脈血時間放射能曲線の測定

  織田 圭一; 石井 賢二; 木村 裕一; 酒井 健也; 長縄 美香; 福士 政広; 石渡 喜一  核医学  43-  (3)  226  -226  2006/10
• FDG脳糖代謝詳細画像の無採血高速作成手法

  木村 裕一; 長縄 美香; 織田 圭一; 石井 賢二; 石渡 喜一  核医学  43-  (3)  229  -229  2006/10
• アミロイドプローベPIBによるアルツハイマー病脳内アミロイド蓄積の検討

  石井 賢二; 石渡 喜一; 木村 裕一; 織田 圭一; 橋本 昌也; William Klunk; Chester Mathis; 金丸 和富; 齊藤 祐子; 村山 繁雄  核医学  43-  (3)  234  -235  2006/10
• ジフェニルアルシン酸暴露者における脳FDG-PET所見

  石井 賢二; 石井 一弘; 川崎 敬一; 織田 圭一; 武田 徹; 塚田 秀夫; 岩崎 信明; 玉岡 晃; 木村 裕一; 石渡 喜一  核医学  43-  (3)  235  -235  2006/10
• [11C]SA4503-PETによるハロペリドールのシグマ1受容体占拠率評価

  石渡 喜一; 織田 健司; 木村 裕一; 坂田 宗之; 織田 圭一; 佐々木 徹; 長縄 美香; 大久保 善朗; 石井 賢二  核医学  43-  (3)  237  -237  2006/10
• [11C]SA4503によるヒト脳σ1受容体のPET動態解析

  坂田 宗之; 木村 裕一; 長縄 美香; 織田 圭一; 石井 賢二; 千原 國宏; 石渡 喜一  核医学  43-  (3)  237  -237  2006/10
• 神経受容体濃度画像化のための平面交差法によるLogan plotの無採血化

  長縄 美香; 矢野 純一; 織田 圭一; 石井 賢二; 石渡 喜一; 木村 裕一  核医学  43-  (3)  237  -237  2006/10
• 脳FDG-PET画像の機種間差補正

  川崎 敬一; 石井 賢二; 織田 圭一; 宮沢 伸彦; 篠原 豊明; 木村 裕一; 石渡 喜一  核医学  43-  (3)  242  -242  2006/10
• Lewy小体型認知症における後頭葉の機能低下に関連する選隔部位の機能亢進

  橋本 昌也; 川崎 敬一; 鈴木 正彦; 井上 聖啓; 三谷 和子; 金丸 和富; 村山 繁雄; 織田 圭一; 木村 裕一; 石渡 喜一; 石井 賢二  核医学  43-  (3)  271  -271  2006/10
• 新規抗ヒスタミン薬オロパタジン内服後の脳内ヒスタミンH1受容体占拠率測定による薬物副作用評価

  田代 学; 望月 秀紀; 石井 賢二; 木村 裕一; 織田 圭一; 佐々木 徹; 石渡 喜一; 谷内 一彦  核医学  43-  (3)  274  -274  2006/10
• 11C-NMSPによるセロトニン受容体描出を用いた中枢性疲労定量評価

  木村 裕一; 藤本 敏彦; 菊地 次郎; 小川 静香; 橋本 昌也; 石川 雅智; 織田 圭一; 石井 賢二; 石渡 喜一  核医学  43-  (3)  275  -275  2006/10
• [11C]TMSX PETを用いた未治療パーキンソン病におけるアデノシンA2A受容体結合能 a preliminary study

  三品 雅洋; 石井 賢二; 北村 伸; 木村 裕一; 長縄 美香; 橋本 昌也; 鈴木 正彦; 織田 圭一; 小林 士郎; 片山 泰朗; 石渡 喜一  核医学  43-  (3)  275  -275  2006/10
• シグマ1受容体に対するフルボキサミンとバロキセチンの占拠率の相違に関する検討

  石川 雅智; 清水 栄司; 伊豫 雅臣; 藤崎 美久; 橋本 謙二; 石井 賢二; 石渡 喜一; 織田 圭一; 木村 裕一  千葉医学雑誌  82-  (4)  242  -242  2006/08
• Automatic Extraction of Brain Surface from FDG-PET Images Using Morphological filters

  YAMAMOTO Yoshinori; KIMURA Yuichi; KYOSO Masaki; ISHIJIMA Masayuki  IEICE technical report  105-  (579)  17  -20  2006/01
• Imaging detailed cerebral glucose metabolism in PET using maximum a posterior criterion and pattern recognition : Search algorithm in feature space

  YAMAGUCHI Jun; KIMURA Yuichi; NAGANAWA Mika; UCHIYAMA Akihiko; YANAGISAWA Masao  IEICE technical report  105-  (579)  13  -16  2006/01
• Relationship between dopamine D-2 and adenosine A(2A) receptors in drug naive Parkinson's disease using TMSX PET

  M. Mishina; K. Ishii; S. Kitamura; Y. Kimura; M. Naganawa; M. Hashimoto; M. Suzuki; K. Oda; M. Hamamoto; S. Kobayashi; Y. Katayama; K. Ishiwata  MOVEMENT DISORDERS  21-  S622  -S622  2006
• Direct estimation of cumulative integrals of the input function for Logan plot in neuroreceptor imaging using intersection searching algorithm

  Mika Naganawa; Y. Kimura; J. Yano; K. Ishiwata  NEUROIMAGE  31-  T89  -T90  2006
• Inter-crystal scatter identification for a depth-sensitive detector using multi-anode outputs

  Eiji Yoshida; Keishi Kitamura; Yuichi Kimura; Fumihiko Nishikido; Kengo Shibuya; Taiga Yamaya; Hideo Murayama  2006 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOL 1-6  1860  -1864  2006  [Refereed]
  
• DPAA等有機ヒ素化合物ばく露者における脳ポジトロンCT(PET)の解析に関する研究

  石井賢二; 織田圭一; 木村裕一; 石渡喜一; 川崎敬一; 斎藤陽子; 石井一弘  平成17年度ジフェニルアルシン酸等の健康影響に関する調査研究｣研究報告  81-85  2006/01
• Use of reference tissue models for quantification of histamine H-1 receptors in human brain by using positron emission tomography and [C-11]doxepin

  Atsuro Suzuki; Keizo Ishii; Manabu Tashiro; Yuichi Kimura; Kenji Ishii; Kiichi Ishiwata; Hideki Mochizuki; Kazuhiko Yanai; Miroshi Watabe  FUTURE MEDICAL ENGINEERING BASED ON BIONANOTECHNOLOGY, PROCEEDINGS  817  -+  2006  [Refereed]
  
• 動脈採血省略法の開発

  長縄美香; 木村裕一  PET通信  52-  10  -11  2006
• Visualized regional imbalance of striatal dopaminergic function in Parkinson's disease

  M Suzuki; K Kawasaki; Y Kimura; K Ishiwata; M Urashima; M Mishina; M Hashimoto; K Inoue; K Ishii  JOURNAL OF THE NEUROLOGICAL SCIENCES  238-  S370  -S371  2005/11
• 糖負荷は連合野のFDG取込みを抑制する(2報)

  川崎 敬一; 石井 賢二; 齊藤 陽子; 織田 圭一; 木村 裕一; 石渡 喜一  核医学  42-  (3)  305  -305  2005/09
• 多系統萎縮症における黒質線条体ドパミン節前・節後機能の相関的解析

  橋本 昌也; 川崎 敬一; 鈴木 正彦; 井上 聖啓; 三谷 和子; 三品 雅洋; 織田 圭一; 木村 裕一; 石渡 喜一; 石井 賢二  核医学  42-  (3)  306  -306  2005/09
• 動脈採血省略定量解析法の脳アデノシンA1およびA2A受容体画像化への適用

  長縄 美香; 木村 裕一; 石井 賢二; 織田 圭一; 三品 雅洋; 成相 直; 石渡 喜一  核医学  42-  (3)  338  -338  2005/09
• 事後確率最大化規範による動態解析推定性能の向上と高速化

  木村 裕一; 長縄 美香; 織田 圭一; 石井 賢二; 石渡 喜一  核医学  42-  (3)  339  -339  2005/09
• アルツハイマー病とレビー小体型痴呆症のFDG-PET所見 剖検病理診断確定例における検討

  石井 賢二; 村山 繁雄; 齊藤 祐子; 織田 圭一; 木村 裕一; 石渡 喜一  核医学  42-  (3)  341  -341  2005/09
• アルツハイマー病とレビー小体型痴呆症のFDG-PET所見 軽度認知障害例における検討

  石井 賢二; 川崎 敬一; 齊藤 陽子; 金丸 和富; 三谷 和子; 織田 圭一; 木村 裕一; 石渡 喜一  核医学  42-  (3)  341  -341  2005/09
• 3D PETにおけるemission/transmission同時収集による吸収補正の検討

  織田 圭一; 石井 賢二; 木村 裕一; 石渡 喜一  核医学  42-  (3)  365  -365  2005/09
• 言語性・非言語性の口舌部運動制御に関わる島皮質の機能局在

  齊藤 陽子; 石井 賢二; 織田 圭一; 木村 裕一; 石渡 喜一; 水澤 英洋  認知神経科学  7-  (2)  145  -145  2005/07
• Partial Volume Correction in PET based on Segmented Brain MRI with Statistical Clustering and Morphological Filter

  OZAKI Hitoshi; KIMURA Yuichi; UCHIYAMA Akihiko  IEICE technical report.  104-  (580)  151  -156  2005/01
• Imaging detailed glucose metabolism in the brain using MAP estimation in Positron Emission Tomography

  Yuichi Kimura; Mika Naganawa  2005 27th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Vols 1-7  4477  -4479  2005  [Refereed]
  
• Practical consideration about cost functions of spatial independent component analysis in medical image processing

  M. Naganawa; Y. Kimura; Y. Manabe; K. Chihara  2005 27th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Vols 1-7  1120  -1122  2005  [Refereed]
  
• Imaging detailed glucose metabolism in the brain using MAP estimation in Positron Emission Tomography.

  Kimura Y; Naganawa M  Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference  5-  4477  -4479  2005  [Refereed]
  
• 薬剤開発と受容体可視化

  木村 裕一  PET通信  52-  10  -11  2005
• 心筋および骨格筋におけるアデノシンA_<2A>受容体に及ぼす持久的トレーニングの影響 : PET研究(運動器, 第59回日本体力医学会大会)

  水野 正樹; 木村 裕一; 時澤 健; 村岡 功  体力科學  53-  (6)  672  -672  2004/12
• [C-11]TMSX PETを用いた健常者脳内アデノシンA2A受容体分布の測定

  三品 雅洋; 石井 賢二; 石渡 喜一; 木村 裕一; 大山 雅史; 阿部 新; 福地 孝明; 小林 士郎; 片山 泰朗  臨床神経学  44-  (12)  1116  -1116  2004/12
• [¹¹C]MPDX PETの加齢性変化

  福光延吉; 石井賢二; 木村裕一; 織田圭一; 佐々木徹; 石渡喜一  核医学  41-  (3)  379  -379  2004/09
• アルツハイマー病における髄液バイオマーカーと局所脳糖代謝の相関

  石井 賢二; 金丸 和富; 齊藤 陽子; 織田 圭一; 木村 裕一; 河村 和紀; 佐々木 徹; 石渡 喜一  核医学  41-  (3)  311  -311  2004/09
• [11C]TMSX-PETによる骨格筋アデノシンA2A受容体計測の可能性

  石渡 喜一; 水野 正樹; 木村 裕一; 河村 和紀; 織田 圭一; 佐々木 徹; 石井 賢二  核医学  41-  (3)  314  -314  2004/09
• 局所脳血流とベンゾジアゼピン受容体PET画像の相関クラスター分析

  織田 圭一; 石井 賢二; 木村 裕一; 大橋 信一郎; 外山 比南子; 佐々木 敏秋  核医学  41-  (3)  341  -341  2004/09
• PET代謝受容体計測による難治てんかん病態の評価

  成相 直; 尤 郁偉; 前原 健寿; 大野 喜久郎; 織田 圭一; 木村 裕一; 石井 賢二; 石渡 喜一; 清水 浩之  核医学  41-  (3)  341  -341  2004/09
• 参照領域フリーな動脈採血省略法を用いたLogan plotによる脳神経受容体の画像化

  長縄 美香; 木村 裕一; 三品 雅洋; 成相 直; 織田 圭一; 石井 賢二; 石渡 喜一  核医学  41-  (3)  341  -341  2004/09
• 動態モデルに基づいたクラスタリングによるLogan plot神経受容体画像の画質改善

  木村 裕一; 石井 賢二; 塚原 美穂子; 織田 圭一; 河村 和紀; 石渡 喜一  核医学  41-  (3)  341  -341  2004/09
• 糖負荷は連合野皮質のFDG取り込みを抑制する

  石井 賢二; 川崎 敬一; 齊藤 陽子; 織田 敬一; 河村 和紀; 木村 裕一; 佐々木 徹; 石渡 喜一  核医学  41-  (3)  367  -367  2004/09
• [C-11]TMSX PETを用いた健常者脳内アデノシンA2A受容体分布の測定

  三品 雅洋; 石渡 喜一; 石井 賢二; 木村 裕一; 織田 圭一; 佐々木 徹; 河村 和紀; 大山 雅史; 福地 孝明; 小林 士郎; 片山 泰朗  核医学  41-  (3)  378  -379  2004/09
• 脳シグマ受容体を指標にした加齢・神経変性疾患・脳腫瘍の新しいPET診断法

  石渡 喜一; 石井 賢二; 成相 直; 木村 裕一; 河村 和紀; 大山 雅史; 三品 雅洋  INNERVISION  19-  (7)  21  -21  2004/06
• Effects of endurance training on adenosine A(2A) receptor density in myocardium and skeletal muscle

  M Mizuno; Y Kimura; K Ishii; K Oda; T Sasaki; K Kawamura; K Ishiiwata; Muraoka, I  MEDICINE AND SCIENCE IN SPORTS AND EXERCISE  36-  (5)  S26  -S26  2004/05
• PETによる新しい神経受容体計測法の難治側頭葉てんかん患者への臨床応用

  成相 直; 前原 健寿; 太田 禎久; 今江 省吾; 大野 喜久郎; 木村 裕一; 石井 賢二; 石渡 喜一  てんかん研究  22-  (1)  49  -49  2004/02
• Supervised clustering approach to form functional images in positron emission tomography

  Y Kimura; Y Takabayashi; J Yamaguchi  PROCEEDINGS OF THE 26TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-7  26-  1896  -1898  2004  [Refereed]
  
• Age-related change in presynaptic and postsynaptic dopaminergic function: The rate of decline and regional correlation in the striatum

  K Ishii; K Oda; Y Kimura; K Kawamura; T Sasaki; K Ishiwata  NEUROIMAGE  22-  T77  -T78  2004
• Calibration procedure for a DOI detector of high resolution PET through mixture Gaussian model

  E Yoshida; Y Kimura; K Kitamura; H Murayama  2003 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-5  2491  -2495  2004  [Refereed]
  
• A quantitative neuroreceptor imaging using independent component analysis with neither serial arterial blood sampling nor use of reference tissue: An adenosine A1 receptor mapping study

  M Naganawa; Y Kimura; K Ishii; K Ishiwata  NEUROIMAGE  22-  T15  -T16  2004
• Visualization of activated microglias in Wernicke-Korsakoff syndrome by [11C]PK11195 and PET

  M Tsukahara; K Ishii; Y Kimura; S Matsushita; S Higuchi; K Ishiwata  NEUROIMAGE  22-  T196  -T197  2004
• Sigma1 receptors in Parkinson's disease

  M Mishina; K Ishiwata; K Ishii; S Kitamura; Y Kimura; K Kawamura; K Oda; T Sasaki; K Mitani; M Ohyama; T Fukuchi; S Kobayashi; Y Katayama  NEUROIMAGE  22-  T122  -T123  2004
• [C-11]TMSX PET for mapping of adenosine A2A receptors in human brain

  M Mishina; K Ishiwata; K Ishii; Y Kimura; K Kawamura; K Oda; T Sasaki; S Kobayashi; Y Katayama  NEUROIMAGE  22-  T85  -T85  2004
• Regional Correlation of Pre- and Post- Synaptic Dopaminergic Function in the Striatum of Parkinson's Disease : A Novel Voxel Based Analysis

  SUZUKI Masahiko; INOUE Kiyoharu; KITAMURA Shin; MISHINA Masahiro; MITANI Kazuko; YAMANOUCHI Hiroshi; ODA Keiichi; KIMURA Yuichi; ISHIWATA Kiichi; ISHII Kenji  CI研究 : progress in computed imaging  25-  (4)  237  -244  2003/12
• 329. PETを用いたヒト心筋および骨格筋におけるA_<2A>アデノシン受容体の定量(呼吸・循環)

  水野 正樹; 木村 裕一; 中村 好男; 村岡 功  体力科學  52-  (6)  879  -879  2003/12
• 抗ヒスタミン薬オロパタジン及びケトチフェン内服後のヒト脳内ヒスタミンH1受容体占拠率の測定

  田代 学; 望月 秀紀; 櫻田 幽美子; 石井 賢二; 木村 裕一; 織田 圭一; 石渡 喜一; 谷内 一彦  日本神経精神薬理学雑誌  23-  (6)  235  -235  2003/12
• アルツハイマー病におけるシグマ受容体リガンド11C-SA4503と糖代謝の検討

  大山 雅史; 石渡 喜一; 石井 賢二; 三谷 和子; 三品 雅洋; 北村 伸; 織田 圭一; 木村 裕一; 河村 和紀; 佐々木 徹; 片山 泰朗  臨床神経学  43-  (12)  989  -989  2003/12
• ヒトにおける[¹¹C]MPDXによるアデノシンA1受容体画像

  福光延吉; 石井賢二; 木村裕一; 佐々木徹; 織田圭一; 森豊; 石渡喜一  核医学  40-  (3)  397  2003/08
• 脳ドーパミン節前・節後機能の加齢変化

  石井 賢二; 織田 圭一; 木村 裕一; 河村 和紀; 佐々木 徹; 石渡 喜一  核医学  40-  (3)  317  -317  2003/08
• FDG脳糖代謝パラメトリック画像作製のための簡略化プロトコル

  木村 裕一; 長縄 美香; 織田 圭一; 石井 賢二; 石渡 喜一  核医学  40-  (3)  347  -347  2003/08
• アデノシンA2A受容体リガンド[11C]TMSXの心臓イメージング剤としての可能性

  石渡 喜一; 河村 和紀; 木村 裕一; 織田 圭一; 石井 賢二  核医学  40-  (3)  373  -373  2003/08
• 脳糖代謝と灰白質容積の加齢変化

  石井 賢二; 織田 圭一; 木村 裕一; 河村 和紀; 佐々木 徹; 石渡 喜一  核医学  40-  (3)  380  -380  2003/08
• 全身FDG-PETにおける同時収集法と三次元連続収集法の比較

  織田 圭一; 石井 賢二; 木村 裕一; 石渡 喜一  核医学  40-  (3)  385  -386  2003/08
• 脳アデノシンA2A受容体リガンド[11C]TMSXの前臨床研究

  石渡 喜一; 汪 維芳; 木村 裕一; 三品 雅洋; 河村 和紀; 織田 圭一; 佐々木 徹; 石井 賢二  核医学  40-  (3)  397  -397  2003/08
• PETアデノシンA1受容体計測の難治側頭葉てんかん患者への臨床応用

  成相 直; 前原 健寿; 今江 省吾; 大野 喜久郎; 佐々木 徹; 織田 圭一; 木村 裕一; 石井 賢二; 石渡 喜一  核医学  40-  (3)  398  -398  2003/08
• Evaluation of [F-18]fluorinated sigma receptor ligands in the conscious monkey brain.

  PH Elsinga; H Tsukada; N Harada; T Kakiuchi; K Kawamura; Y Kimura; W Vaalburg; T Kobayashi; K Ishiwata  JOURNAL OF NUCLEAR MEDICINE  44-  (5)  70P  -70P  2003/05
• Imaging of adenosine Al receptors in the human brain by positron emission tomoraphy with C-11-MPDX.

  N Fukumitsu; K Ishii; Y Kimura; K Oda; T Sasaki; Y Mori; K Ishiwata  JOURNAL OF NUCLEAR MEDICINE  44-  (5)  69P  -69P  2003/05
• Midbrain hypometabolism: An early diagnostic sign for progressive supranuclear palsy.

  M Mishina; M Ohyama; K Ishii; K Mitani; K Oda; Y Kimura; T Sasaki; K Ishiwata; T Fukuchi; S Kobayashi; S Kitamura; Y Katayama  JOURNAL OF NUCLEAR MEDICINE  44-  (5)  233P  -233P  2003/05
• C-15 PET による新しい神経受容体計測法の難治側頭葉てんかん患者への臨床応用

  成相 直; 前原 健寿; 太田 禎久; 今江 省吾; 木村 裕一; 石井 賢二; 石渡 喜一  日本てんかん学会プログラム・予稿集  (37)  141  -141  2003
• Punctional image on glucose metabolism in brain using PET with short time scan

  Y Kimura; Y Takabayashi; K Oda; K Ishii; K Ishiwata  PROCEEDINGS OF THE 25TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-4  25-  967  -970  2003  [Refereed]
  
• Brain histamine H1 receptor occupancy of olopatadine and ketotifen: A comparative PET study.

  M Tashiro; H Mochizuki; Y Sakurada; K Ishii; Y Kimura; K Ishiwata; K Yanai  JOURNAL OF PHARMACOLOGICAL SCIENCES  91-  90P  -90P  2003
• Simplified measurement of histamine H-1 receptor in human brains with PET

  H Mochizuki; Y Kimura; K Ishii; K Oda; T Sasaki; M Tashiro; K Yanai; K Ishiwata  IEEE EMBS APBME 2003  198  -199  2003  [Refereed]
  
• Implementation of statistical clustering for voxel-based kinetic analysis in PET

  Y Kimura; Y Noshi; K Ishii; K Oda  2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3  1322  -1324  2003  [Refereed]
  
• 陽電子断層装置を用いた脳機能の可視化

  木村 裕一  電気学会誌  123-  (3)  152  -155  2003
• 138.運動後における筋酸素摂取量と血流量の空間的関連性(呼吸・循環)

  水野 正樹; 木村 裕一; 岩川 孝志; 中村 好男; 村岡 功  体力科學  51-  (6)  611  -611  2002/12
• シグマ受容体リガンド11C-SA4503によるアルツハイマー病への臨床応用

  大山 雅史; 石渡 喜一; 石井 賢二; 三谷 和子; 三品 雅洋; 北村 伸; 織田 圭一; 木村 裕一; 河村 和紀; 佐々木 徹; 片山 泰朗  臨床神経学  42-  (12)  1249  -1249  2002/12
• PETによる脳シグマ1受容体分布描出

  石井 賢二; 木村 裕一; 河村 和紀; 織田 圭一; 石渡 喜一  臨床神経学  42-  (12)  1265  -1265  2002/12
• アルツハイマー病におけるシグマ受容体リガンド11C-SA4503と糖代謝の検討

  大山 雅史; 石井 賢二; 三品 雅洋; 三谷 和子; 北村 伸; 織田 圭一; 木村 裕一; 河村 和紀; 佐々木 徹; 片山 泰朗; 石渡 喜一  核医学  39-  (3)  326  -326  2002/09
• ヒスタミンH1受容体のPETスタティック測定

  望月 秀紀; 木村 裕一; 石井 賢二; 織田 圭一; 佐々木 徹; 田代 学; 谷内 一彦; 石渡 喜一  核医学  39-  (3)  328  -328  2002/09
• 脳アデノシンA1受容体リガンド[11C]MPDXの前臨床研究

  石渡 喜一; 成相 直; 木村 裕一; 織田 圭一; 河村 和紀; 石井 賢二; 千田 道雄; 島田 純一  核医学  39-  (3)  328  -328  2002/09
• パーキンソン病における節前・節後ドーパミン機能の相関的解析 voxel based analysis

  石井 賢二; 三品 雅洋; 鈴木 正彦; 三谷 和子; 織田 圭一; 木村 裕一; 河村 和紀; 佐々木 徹; 石渡 喜一  核医学  39-  (3)  340  -340  2002/09
• SPM99を用いた老年変性疾患のFDG PET画像解析における加齢変化の除去 age matchとANCOVA

  三品 雅洋; 大山 雅史; 石井 賢二; 石渡 喜一; 織田 圭一; 河村 和紀; 木村 裕一; 佐々木 徹; 小林 士郎; 北村 伸; 片山 泰朗  核医学  39-  (3)  341  -341  2002/09
• ヒト脳シグマ1受容体分布の正常加齢変化について

  石井 賢二; 木村 裕一; 河村 和紀; 織田 圭一; 佐々木 徹; 石渡 喜一  核医学  39-  (3)  376  -376  2002/09
• 統計的クラスタリング動態解析によるFDGパラメトリック画像

  木村 裕一; 石井 賢二; 織田 圭一; 北村 圭司; 石渡 喜一  核医学  39-  (3)  388  -388  2002/09
• 独立成分分析の適用によるPET動態画像からの血漿放射能曲線の抽出

  長縄 美香; 木村 裕一; 石井 賢二; 織田 圭一; 石渡 喜一  核医学  39-  (3)  396  -396  2002/09
• [C-11]CFTと[C-11]raclopride PET画像の相関クラスター分析

  織田 圭一; 石井 賢二; 大橋 信一郎; 上村 幸司; 外山 比南子; 木村 裕一; 石渡 喜一  核医学  39-  (3)  397  -397  2002/09
• Mapping of sigma(1) receptors by C-11-SA4503-distribution and aging effect in normal human brain

  K Ishii; Y Kimura; K Kawamura; K Oda; T Sasaki; K Ishiwata  NEUROIMAGE  16-  (3)  S31  -S31  2002/07
• An increase of binding potentials of C-11-SA4503 to sigma, receptors in the aged monkey brain.

  K Kawamura; Y Kimura; H Tsukada; T Kobayashi; M Ohyama; K Matsuno; K Ishii; K Ishiwata  JOURNAL OF NUCLEAR MEDICINE  43-  (5)  235P  -235P  2002/05
• The first evaluation of sigma1 receptors in patients with Alzheimer's disease using PET and a newly developed ligand: C-11 SA4503.

  M Ohyama; K Ishiwata; K Ishii; M Mishina; S Kitamura; K Kawamura; Y Kimura; T Sasaki; K Oda; K Mitani; Y Katayama  JOURNAL OF NUCLEAR MEDICINE  43-  (5)  243P  -243P  2002/05
• Normal distribution of GABA(A) receptor in visual cortex of early onset blindness.

  M Mishina; M Senda; M Kiyosawa; K Ishiwata; AG De Volder; H Nakano; H Toyama; K Oda; Y Kimura; K Ishii; T Sasaki; M Ohyama; Y Komaba; S Kobayashi; S Kitamura; Y Katayama  JOURNAL OF NUCLEAR MEDICINE  43-  (5)  253P  -253P  2002/05
• Mixture Gaussian Model-based scatter correction for PET image

  CHIBA Yoshiaki; KIMURA Yuichi; ODA Keiichi; UCHIYAMA Akihiko  IEICE technical report.  101-  (581)  95  -99  2002/01
• Formation of statistically reliable parametric image in positron emission tomography : Image on glucose metabolism with statistical clustering

  NOSHI Yasuhiro; KIMURA Yuichi; ISHII Kenji; UCHIYAMA Akihiko  IEICE technical report.  101-  (581)  101  -106  2002/01
• Segmentation of MRI Brain Image Using Three-dimensional Morphology : Mixture Gaussian Model Combined with Morphological Filter

  OKANO Masafumi; KIMURA Yuichi; YAMASHITA Takumi; UCHIYAMA Akihiko  IEICE technical report.  101-  (580)  37  -42  2002/01
• Fully automated segmentation of MRI brain image, using mixture Gaussian model and three-dimensional morphological filter

  M Okano; Y Kimura; K Ishii; A Uchiyama; K Ishiwata  SECOND JOINT EMBS-BMES CONFERENCE 2002, VOLS 1-3, CONFERENCE PROCEEDINGS  997  -998  2002  [Refereed]
  
• Statistical model-based scatter correction for 3D PET

  Y Chiba; Y Kimura; K Kitamura; K Oda; A Uchiyama; K Ishiwata  SECOND JOINT EMBS-BMES CONFERENCE 2002, VOLS 1-3, CONFERENCE PROCEEDINGS  965  -966  2002  [Refereed]
  
• Imaging glucose metabolism of brain using PET with clustering analysis for kinetics

  Y Noshi; Y Kimura; K Ishii; A Uchiyama; K Oda; K Kitamura; K Ishiwata  SECOND JOINT EMBS-BMES CONFERENCE 2002, VOLS 1-3, CONFERENCE PROCEEDINGS  951  -952  2002  [Refereed]
  
• 80.ポジトロンCT(PET)を用いた骨格筋における水分布体積の定量化(【運動器】)

  水野 正樹; 木村 裕一; 大森 一伸; 中村 好男; 村岡 功  体力科學  50-  (6)  772  -772  2001/12
• 習熟随意運動施行時における黒質線条体系ドパミンニューロンの役割

  石井 賢二; 木村 裕一; 織田 圭一; 石渡 喜一; 佐々木 徹; 千田 道雄  臨床神経学  41-  (11)  973  -973  2001/11
• ポジトロンCTを用いた高強度運動後における局所筋循環の経時変化(一般演題,第12回東京女子医科大学スポーツ健康医学研究会(平成12年11月6日))

  水野 正樹; 木村 裕一; 中村 好男; 村岡 功; 千田 道雄  東京女子医科大学雑誌  71-  (9)  736  -737  2001/10
• 痴呆研究の展望 老人研プロジェクトの取組みから

  安藤 進; 石渡 喜一; 石井 賢二; 木村 裕一; 織田 圭一  核医学技術  21-  (4)  250  -254  2001/10
• 11C-Doxepinによる脳ヒスタミン受容体の解析

  木村 裕一; 望月 秀紀; 石井 賢二; 織田 圭一; 佐々木 徹; 田代 学; 谷内 一彦; 石渡 喜一  核医学  38-  (5)  594  -594  2001/09
• サル脳シグマ1受容体の加齢変化

  河村 和紀; 木村 裕一; 塚田 秀夫; 小林 直之; 松野 聖; 石井 賢二; 石渡 喜一  核医学  38-  (5)  593  -593  2001/09
• ヒト脳におけるシグマ1受容体分布描出

  石井 賢二; 木村 裕一; 河村 和紀; 織田 圭一; 佐々木 徹; 石渡 喜一  核医学  38-  (5)  593  -593  2001/09
• シグマ受容体リガンド11C-SA4503によるアルツハイマー病への臨床応用

  大山 雅史; 石渡 喜一; 石井 賢二; 三谷 和子; 三品 雅洋; 北村 伸; 千田 道雄; 織田 圭一; 木村 裕一; 片山 泰朗  核医学  38-  (5)  593  -593  2001/09
• [11C]RacloprideとPETによる随意運動遂行時の内因性ドパミン放出測定

  石井 賢二; 木村 裕一; 織田 圭一; 石渡 喜一; 佐々木 徹; 千田 道雄  核医学  38-  (5)  568  -568  2001/09
• PET定性測定における検査時間短縮の試み

  織田 圭一; 石井 賢二; 木村 裕一  核医学  38-  (5)  573  -573  2001/09
• 統計的手法を用いたクラスタリング動態解析によるPETパラメトリック画像の生成

  木村 裕一; 石井 賢二; 織田 圭一  核医学  38-  (5)  575  -575  2001/09
• Segmentation of Magnetic Resonance Images of Brain with Mixture Gaussian Model

  OKANO Masafumi; KIMURA Yuichi; UCHIYAMA Akihiko  生体・生理工学シンポジウム論文集  16-  395  -398  2001/08
• Extraction of plasma time-activity curve from PET images using intentionally breakdown of independent component analysis

  NAGANAWA Mika; MATANI Ayumu; KIMURA Yuichi  生体・生理工学シンポジウム論文集  16-  407  -410  2001/08
• Formation of statistically reliable parametric image in positron emission tomography : Effect of incorporating hierarchal clustering algorithm

  NOSHI Yasuhiro; KIMURA Yuichi; UCHIYAMA Akihiko  IEICE technical report.  101-  (239)  17  -23  2001/07
• Mapping of sigma(1) receptors in living human brain

  K Ishii; K Ishiwata; Y Kimura; K Kawamura; K Oda; M Senda  NEUROIMAGE  13-  (6)  S984  -S984  2001/06
• ポジトロンによる痴呆の早期診断と病態生理の研究 ベンゾジアゼピン受容体のイメージングによる痴呆の病態解析

  千田 道雄; 石渡 喜一; 石井 賢二; 織田 圭一; 佐々木 徹; 木村 裕一; 三谷 和子; 三品 雅洋; 大山 雅史; 外山 比南子  長期特別プロジェクト成果報告書 老人性痴呆に関する総合的研究  平成12年度-  35  -38  2001/03
• Extraction of vessel-related information from pet images without continuous blood sampling using modified independent component analysis

  M Naganawa; A Matani; Y Kimura  PROCEEDINGS OF THE 23RD ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-4  23-  2744  -2747  2001  [Refereed]
  
• Formation of parametric images in positron emission tomography using a clustering-based kinetic analysis with statistical clustering

  Y Kimura; Y Noshi; K Oda; K Ishii  PROCEEDINGS OF THE 23RD ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-4  23-  2763  -2765  2001  [Refereed]
  
• 208.ポジトロンCTを用いた高強度運動後における局所筋循環の経時変化

  水野 正樹; 木村 裕一; 大森 一伸; 中村 好男; 村岡 功; 千田 道雄  体力科學  49-  (6)  770  -770  2000/12
• Extraction of Plasma Time-Activity Curve in Positron Emission Tomography Using Independent Component Analysis

  NAGANAWA Mika; MATANI Ayumu; KIMURA Yuichi  IEICE technical report.  100-  (464)  33  -38  2000/11
• Fast Method for Image Based Compartment Model Analysis

  KIMURA Yuichi; SENDA Michio  生体・生理工学シンポジウム論文集  15-  117  -120  2000/10
• SPMにおける異なるtemplateによる解剖学的標準化の検討

  大山 雅史; 三品 雅洋; 千田 道雄; 石井 賢二; 織田 圭一; 木村 裕一; 片山 泰朗  核医学  37-  (5)  579  -579  2000/09
• クラスタリング動態解析によるPETパラメトリック画像の生成

  木村 裕一; 千田 道雄; 石井 賢二  核医学  37-  (5)  580  -580  2000/09
• SPMによる痴呆脳PET診断のための基礎検討 解剖学的標準化法と対照領域について

  石井 賢二; 馬 云川; 木村 裕一; 織田 圭一; 千田 道雄  核医学  37-  (5)  543  -543  2000/09
• 局所脳萎縮を呈する疾患の形態変化と機能変化の相関について

  石井 賢二; 木村 裕一; 織田 圭一; 千田 道雄  核医学  37-  (5)  542  -542  2000/09
• Functional Imaging by Kinetic Analysis with Positron Emission Tomography

  KIMURA Yuichi  IEICE technical report.  100-  (172)  31  -36  2000/07
• Formation of FDG parametric images based on clustering and principal components.

  Y Kimura; K Ishii; M Senda; NH Alpert  JOURNAL OF NUCLEAR MEDICINE  41-  (5)  100P  -101P  2000/05
• Benzodiazepine Receptor Distribution and Cerebral Blood Flow in Early Blindness : A PET Study

  MISHINA Masahiro; SENDA Michio; KIYOSAWA Motohiro; VOLDER Anne De; TOYAMA Hinako; ISHIWATA Kiichi; ODA Keiichi; KIMURA Yuichi; NAKANO Hideki; OHYAMA Masashi; KITAMURA Shin; KATAYAMA Yasuo  Keio journal of medicine  49-  A114  -A116  2000/02
• Improving Signal To Noise Ratio and Calculation Speed to Form Functional Image of Positron Emission Tomography By Clustering Base On Kinetics Model

  KIMURA Yuichi; SENDA Michio; ALPERT Nathaniel M.  IEICE technical report.  99-  (583)  29  -35  2000/01
• 在宅健康管理のための家庭台所における日常行動検知

  落合嗣郎; 西原美敬; 庄司健; 木村裕一; 斉藤浩一; 小川充洋; 田村俊世; 戸川達男; 土屋喜一  バイオエンジニアリング講演会講演論文集  12th-  155  -156  2000/01
• An attempt of unconstraint heart and respiratory measurement by using photoplethysmograph for home health monitoring

  OGAWA Mitsuhiro; TAMURA Toshiyo; SHOUJI Ken; OHTA Manabu; KIMURA Yuichi; TOGAWA Tatsuo  IEICE technical report. ME and bio cybernetics  99-  (83)  37  -40  1999/05
• Improved signal to noise ratio in parametric images by cluster analysis.

  Y Kimura; HB Hsu; H Toyama; M Senda; AJ Fischman; NM Alpert  JOURNAL OF NUCLEAR MEDICINE  40-  (5)  288P  -288P  1999/05
• Improving signal-to-noise ratio in FDG parametric images by cluster analysis

  Y Kimura; M Senda; NM Alpert  1999 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1-3  1269  -1271  1999  [Refereed]
  
• Effect of reconstruction algorithm on parametric images in PET dynamic study: Comparison between FBP and OS-EM

  K Oda; H Toyama; K Uemura; Y Ikoma; Y Kimura; M Senda  1999 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1-3  1542  -1545  1999  [Refereed]
  
• THERMOGRAPHY OF ANCIENT GREECE

  OTSUKA Kimio; ASAI Akimasa; KIMURA Yuichi; TOGAWA Tatsuo  Biomedical thermology : the journal of the Japanese Society of Thermorogy = 医学・生物学サーモロジー  18-  (3)  142  -145  1998/12
• 383.ポジトロンCT(PET)による高強度運動後の骨格筋糖代謝の検討

  大森 一伸; 木村 裕一; 久野 譜也; 村岡 功; 太田 冨貴雄; 千田 道雄  体力科學  47-  (6)  894  -894  1998/12
• Creation of a Dynamic Digital Phantom and its Application to a Kinetic Analysis

  IKOMA Yoko; TOYAMA Hinako; YAMADA Takamitsu; UEMURA Koji; KIMURA Yuichi; SENDA Michio; UCHIYAMA Akihiko  核医学  35-  (5)  293  -303  1998/06
• 358.自転車エルゴメータ運動のペダル回転数が下肢関節に及ぼす影響

  星川 秀利; 玉木 啓一; 佐藤 吉朗; 藤本 浩志; 木村 裕一; 斉藤 浩一; 中村 好男; 村岡 功  体力科學  46-  (6)  791  -791  1997/12
• Evaluation of pathological heterogeneity in diffuse encephalopathy by mapping fractal dimension on cortical projection images.

  K Uemura; A Kobayashi; H Toyama; Y Kimura; K Ishii; K Oda; M Senda; A Uchiyama  JOURNAL OF NUCLEAR MEDICINE  38-  (5)  883  -883  1997/05
• Comparison of the Number of Parameters Using Nonlinear Iteration Methods for Compartment Model Analysis with ^<18>F-FDG Brain PET

  TAGUCHI Atsushi; TOYAMA Hinako; KIMURA Yuichi; SENDA Michio; UCHIYAMA Akihiko  核医学  34-  (1)  25  -34  1997/01
• A study for personal identification on bathtub ECG by using a wavelet transform and a neural network. Effectiveness about wavelet transform.

  小川充洋; 木村裕一; 田村俊世; 戸川達男  生体・生理工学シンポジウム論文集  11th-  513  -516  1996/11
• Development of automatic monitoring system for home health care.

  依田美紀子; 鈴木正宣; 小川充洋; 木村裕一; 田村俊世; 戸川達男; 若松秀俊  生体・生理工学シンポジウム論文集  11th-  401  -404  1996/11
• Correction for partial volume effect in quantitative polar map of the myocardium.

  T Itou; H Toyama; Y Kimura; K Ishii; K Oda; M Senda; H Satoh  JOURNAL OF NUCLEAR MEDICINE  37-  (5)  671  -671  1996/05
• Feasibility of cerebral blood volume estimation and its effect on the rate constants in FDG compartment model analysis.

  H Toyama; A Taguchi; Y Matsumura; Y Kimura; K Uemura; K Ishii; K Oda; M Senda  JOURNAL OF NUCLEAR MEDICINE  37-  (5)  996  -996  1996/05
• P388 ^<13>N-NH_3PETによる心筋血流量の定量化-簡便法、2コンパートメント法、Patlak法、3コンパートメント法の比較

  橘川 志延; 山内 雅人; 相生 真吾; 氷見 寿治; 増田 善昭; 吉田 勝哉; 外山 比南子; 木村 裕一  Japanese circulation journal  60-  446  -446  1996/02
• 366.自転車エルゴメーター駆動時の膝関節トルクに及ぼすペダル回転数の影響

  佐藤 吉朗; 星川 秀利; 玉木 啓一; 藤本 浩志; 木村 裕一; 斎藤 浩一; 中村 好男; 村岡 功  体力科學  44-  (6)  789  -789  1995/12
• A study for personal identification on bathtub ECG by using a wavelet transform and a neural network.

  小川充洋; 依田美紀子; 出井清之; 木村裕一; 田村俊世; 戸川達男; 土屋喜一  生体・生理工学シンポジウム論文集  10th-  481  -484  1995/11
• Fuzzy理論を用いたCompartment Model解析法の開発(一般講演2,ファジィ理論、ニューロサイエンス、およびカオスの医療と健康への応用を考える)

  田口 篤; 外山 比南子; 木村 裕一; 仁科 光貴; 千田 道雄; 内山 明彦  バイオメディカル・ファジィ・システム学会大会講演論文集 : BMFSA  (7)  16  -18  1994/12
• 138.自転車エルゴメータ駆動時の力効率指数と負荷強度の関係

  星川 秀利; 玉木 啓一; 藤本 浩志; 木村 裕一; 中村 好男; 村岡 功  体力科學  43-  (6)  575  -575  1994/12
• 80.鍛錬度が自転車運動の伝達ロスに及ぼす影響

  星川 秀利; 玉木 啓一; 中村 好男; 村岡 功; 窪田 登; 藤本 浩志; 木村 裕一  体力科學  42-  (6)  606  -606  1993/12
• Tracer kinetic modeling in nuclear medicine

  H. Toyama; Y. Kimura  Kakuigaku  30-  (12)  1497  -1501  1993
• モデル解析

  外山比南子; 木村裕一  核医学  30-  1497  -1501  1993  [Refereed]
  
• Simplex' の使い方

  木村裕一; 外山比南子  Isotope News  463-  28  1993
• 426.力効率指数からみたペダリングの評価

  星川 秀利; 中村 好男; 村岡 功; 玉木 啓一; 木村 裕一; 藤本 浩志  体力科學  41-  (6)  863  -863  1992/12
• Estimation of Respiratory Sinus by Using Adaptive Filter

  Kimura Yuichi; Nakamura Yoshio; Yamanouchi Toshiaki; Muraoka Isao  Japanese Journal of Physical Fitness and Sports Medicine  40-  (6)  563  -563  1991/12
• 運動下における生体信号の周波数解析

  木村 裕一  ヒューマンサイエンス  4-  (1)  26  -32  1991
• Spectral Analysis of Heart Rate Variability during Constant and Pseudorandom Exercise :

  NAKAMURA Yoshio; TAMAKl Keiichi; KIMURA Yuichi  The Annals of physiological anthropology  9-  (2)  185  -190  1990
• Recession of pneumogenic heart rate variability during incremental cycle exercise

  Nakamura Yoshio; Tamaki Keiichi; Kimura Yuichi; Muraoka Isao  Japanese Journal of Physical Fitness and Sports Medicine  38-  (6)  273  -273  1989/12
• スポーツにおける電子計測とデータ処理

  木村裕一; 内山明彦  8-  (1)  9  -14  1989
• 体力開発と評価 --- 体力開発における評価 ---

  木村裕一; 内山明彦  ヒューマンサイエンス  1-  (1)  77  -80  1988  [Refereed]
  

Industrial Property Rights

• 画像生成方法

  2002-10282
• 放射線投影データの補正方法

  2002-95204
• 放射線位置検出器の校正方法

  2003-200616
• 放射線同時計数処理方法、放射線同時計数処理プログラムおよび放射線同 時計数処理記憶媒体、並びに放射線同時計数装置およびそれを用いた核医学診断 装置、記憶媒体

  2007-71858
• 液体採取装置、測定装置並びにそれらを備えた液体採取測定システム

  2008-050803

Awards & Honors

• 2019/06 日本生体医工学会 Young Investigator's Award
   深層畳み込みオートエンコーダーを用いた健常データの教師無し学習による病変認識特徴量の汎用的自動生成 japan_society 

  受賞者: 牛房 和之受賞研究を指導。
• 2017/11 日本核医学会・核医学理工分科会 奨励研究賞
   PETアミロイドイメージングによるアルツハイ マー病の早期画像診断のための雑音除去アルゴリズムの性能評価 japan_society 

  受賞者: 山田 誉大受賞研究を指導
• 2017/06 日本青年会議所 超生産性大賞
   超ライフの創出 ー ゆりかごのデータから墓場のデータまで ー 

  受賞者: 永岡 隆;吉田 久;木村 裕一
• 2012/11 日本生体医工学会 関東支部 若手発表会 優秀発表賞
   ウェアラブルモーションセサを用いた歩行動作計測によるパーキンソ病患者の治療効果評価 

  受賞者: 須田 雄貴;内山 智之;樋口 佳則;関根 正樹;木村 裕一;田村 俊世
• 2011 日本核医学会 Hisada Award
   Quantitative Analysis of Dopamine Tranporters in Human Brain Using [11C]PE2I and Positron Emission Tomography: Evaluation of Refernce Tissue Models 

  受賞者: C Seki;H Ito;T Ichimiya;R Arakawa;Y Ikoma;M Shidahara;J Maeda;A Takano;H Takahashi;Y Kimura;K Suzuki;I Kanno;T Suhara
• 2011 日本医用画像工学会 大会奨励賞,
   パラメトリック固有空間を利用したPET 動態データの雑音除去 

  受賞者: 星野直輝;本谷秀堅;坂口和也;坂田宗之;石渡喜一;木村裕一
• 2009 日本老人医学会 Best Article Award
   Effects of a Robotic Walking Exercise on Walking Performance in Community-Dwelling Elderly Adults 

  受賞者: Hiroyuki Shimada;Takashi Hirata;Yuichi Kimura;Takako Naka;Keishiro Kikuchi;Keiichi Oda;Kenji Ishii;Kiichi Ishiwata;Takao Suzuki
• 2008 Japanese Society of Nuclear Medicine Annals of Nuclear Medicine Frequently Cited Paper 2011, 2013, and 2014
   Low Density of Sigma1 Receptros in Early Alzheimer's Disease 

  受賞者: Masahiro Mishina;Masaki Ohyama;Kenji Ishii;Shin Kitamura;Yuichi Kimura;Kei-ichi Oda;Kazunori Kawamura;Toru Sasaki;Shiro Kobayashi;Yasuo Katayama;Kiichi Ishiwata
• 2001/01 日本核医学会 Article Award, JSNM
   \Fast and Reliable Method to Generate FDG Parametric Images by Clustering Voxels Based on Principal Components japan_society 

  受賞者: 木村 裕一
• 1996 日本医用画像工学会論文賞
  
• Medical Imaging
  
• Article of the year 1995 in Japanese Society of
  

Research Grants & Projects

• 臨床研究法が医療機器開発研究に与えた影響の実態把握に向けた調査研究

  厚生労働省：令和3年度厚生労働行政推進事業費補助金 (厚生労働科学特別研究事業)

  Date (from‐to) : 2021/08 -2022/03 

  Author : 黒田知宏; 杉町 勝; 木村裕一; 大城 理; 村垣 義浩; 佐久間 一郎; 鈴木 孝司; 鎮西清行; 吉元俊輔; 櫻井 理紗; 中村秀夫
• AMPA受容体PET薬剤([11C]K-2)を用いた臨床PETデータの解析

  横浜市立大学：

  Date (from‐to) : 2021/06 -2022/03 

  Author : 木村裕一
• フロルベタピル(18F)注射液を用いたアミロイドイメージングによる診断インパクト臨床研究

  国立精神・神経医療研究センタ：

  Date (from‐to) : 2019/04 -2022/03
• AMPA受容体標識PETプローブを用いた先進神経疾患横断的研究

  日本医療研究開発機構：

  Date (from‐to) : 2020/04 -2021/03 

  Author : 高橋拓磨
• (放射性標識)新規AMPA受容体PETイメージング製剤によるてんかん焦点同定補助診断薬としての臨床開発

  日本医療研究開発機構：橋渡し研究戦略的推進プログラム

  Date (from‐to) : 2018/04 -2019/03 

  Author : 高橋 拓磨
• Study on measurement of mice brain glucose metabolism by small animal PET / CT

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2015/04 -2018/03 

  Author : takenaka akinori; toyama hiroshi; kimura yuichi

   

  This study aims at evaluating fully automated blood sampling system for kinetic analysis in mice PET studies.Recently, we have developed fully automated blood sampling system (ABDS; Automatic Blood Dispensing System). We verified the operability of ABDS and performed a complete quantitative measurement of glucose cerebral metabolic rate (CMRG1c) in mice using ABDS for the first use, and its usefulness is reported here. CMRG1c in mice was in agreement with the results in the manual blood sampling method reported in the past. The automated micro-liter ordered blood sampling system would be useful for absolute quantification in mice PET studies.
• 脳FDG-PETおよびMRIと機械学習を用いた高精度な認知症自動識別診断

  日本学術振興会：科学研究費補助金, 基盤研究(C)

  Date (from‐to) : 2016/04 -2018/03 

  Author : 坂田 宗之
• 地域・産学連携のためのライフイノベーション拠点形

  文部科学省：私立大学戦略的研究基盤形成支援事業

  Date (from‐to) : 2014/04 -2018/03 

  Author : 本津茂樹
• 認知症診断のためのAβ, 糖代謝, 脳形態変化, 血中成分の経時変化統合手法の構築

  日本学術振興会：科学研究費補助金, 新学術領域研究(研究領域提案型)

  Date (from‐to) : 2015/04 -2017/03 

  Author : 木村 裕一
• 実用化を目指した有望なDNA合成画像診断薬4DSTの18F化とその臨床応用

  日本学術振興会：科学研究費補助金, 基盤研究(B)

  Date (from‐to) : 2014/04 -2017/03 

  Author : 豊原潤
• ロボットスーツを用いたリハビリテーションプロトコルの開発と有効性に関する検討

  日本学術振興会：科学研究費補助金, 基盤研究(C)

  Date (from‐to) : 2012/04 -2016/03 

  Author : 河西理恵
• 院内製造PET薬剤の合成装置を用いた核医学診断技術の臨床応用に関するレギュラトリーサイエンスの研究

  厚生労働省：厚生労働科学研究費補助金, 医薬品・医療機器等レギュラトリーサイエンス総合研究事業

  Date (from‐to) : 2013/04 -2015/03 

  Author : 井上 登美夫
• マウスPET定量分子イメージングへのμL自動採血・代謝物分析・雑音低減法の開発

  日本学術振興会：科学研究費補助金, 基盤研究(C)

  Date (from‐to) : 2012/04 -2015/03 

  Author : 木村 裕一
• Research on inter-scanner difference and improvement of quantitative analysis for multi-center study inpositron emission tomography.

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2010 -2012 

  Author : ODA Keiichi; ISHII Kenji; SAKATA Muneyuki; KIMURA Yuichi; NISHIO Tomoyuki

   

  We showed scanner dependence of brain 18F-FDG and 11C-PiB images by using phantom examination with nine kinds of PET scanners. We used two types of phantoms, cylindrical phantom with 15cm inside diameter and three-dimensional brain phantom, and we set the body phantom on the bed to examine the effect of scatter and random coefficients from outside of the axial field of view (AFOV). Radioactivity and distance of the two phantoms were determined by a pilot study to obtain a condition similar to clinical study. Axial uniformity was evaluated by circular region of interest (ROI) of 12cm diameter, set in the center of the reconstruction image of the cylindrical phantom. As a result, the standardized uptake value (SUV) was lower than the true value in some scanners, and there was a scanner in which the axial uniformity was deteriorated by high radioactivity outside the AFOV. In the cylindrical phantom, the axial uniformity of the scanner was improved using the new dead-time correction method; however, it was not improved in the 3D brain phantom. Quality-controlled PET scanners are important to maintain constant levels for multicenter studies.
• Signal source of functional MRI under heavy diffusion weighting

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2009 -2011 

  Author : OBATA Takayuki; MASAMOTO Kazuto; AOKI Ichio; IKEHIRA Hiroo; OHBAYASHI Shigeru; KIMURA Yuichi

   

  This project aimed to make clear the mechanism of functional magnetic resonance imaging under heavy diffusion weighting(DfMRI). Our results from human and animal MRI indicated that the main source of DfMRI signal is BOLD related, but the signal changes were different from usual BOLD. The human data also included some diffusion related signal contribution to DfMRI. Taking in vitro aquaporin data into consideration, DfMRI may reflect intracellular BOLD and water diffusion changes.
• Methodological development of quantitative tracer kinetic analysis in rodents using small animal PET.

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2008 -2010 

  Author : SEKI Chie; HIGUCHI Makoto; KIMURA Yuichi

   

  PET imaging using transgenic mice is one of the advantageous methods for the development of the diagnostic imaging technology of neurological disease. Quantitative analysis of radioligand using arterial input function (AIF) provides precise kinetics in the living organs but the measurement of AIF is difficult in mice. In the present study the measurement of AIF was optimized for kinetic analysis and applied to amyloid β plaque ligand for the evaluation of amyloid β deposition in Alzheimer's disease model mice.
• Quantitative neuroreceptor imaging for mice using PET : development of micro litter ordered blood radioactivity counting system and the technique to omit arterial blood sampling

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2008 -2010 

  Author : KIMURA Yuichi; TOYAMA Hiroshi; KITAMURA Keishi; HIGUCHI Makoto; SHIDAHARA Miho; HONTANI Hidekata; SEKI Chie; NISHIMOTO Takahiro; WADA Yasuhiro; NAGANAWA Mika; SAKAGUCHI Kazuya

   

  In this study, the methods for radioactivity counting system for micro-liter ordered blood were investigated. Also, the algorithm to omit arterial blood sampling was studied. For fully quantitative functional imaging using positron emission tomography (PET), the radioactivity concentration in arterial blood is required, and therefore, arterial blood sampling should be conducted. However, due to the small size in mice, the arterial blood sampling is an issue for PET quantitative measurement. This study aimed to realize quantitative PET functional imaging for mice, the system to measure radioactivity concentration in a few micro-liter arterial blood and the algorithm fo reduce the noise in PET data derived from mice based on MAP estimation were investigated.
• Organization of PET brain bank

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2008 -2010 

  Author : ISHIWATA Kiichi; NARIAI Tadashi; MISHINA Masahiro; ISHII Kenji; ODA Keiichi; SAKATA Muneyuki; TOYOHARA Jun; KIMURA Yuichi

   

  To encourage PET pathophysiological studies and diagnosis of brain functions and brain disorders in Japan, practical and reliable database of many PET probes which evaluate the basic brain function such as blood flow and glucose metabolism and the neural transmission system was built. The database covers normal subjects including elderly and patients with brain disorders for several probes. Methodological improvement of PET measurement and data analysis with PET-MRI fusion was also performed.
• Development of the algorithm for quantitative neuroreceptor imaging using PET without serial arterial blood sampling and reference region

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2006 -2007 

  Author : KIMURA Yuichi; ISHIWATA Kiichi; ODA Keiichi; ISHII Kenji; WATABE Hiroshi

   

  This study aims at developing algorithms for fully quantitative neuroreceptor imaging using PET without serial arterial blood sampling and reference regions. For omission of serial arterial blood sampling, variational Bayesian approach and an intersectional searching approach were investigated based on Logan graphical analysis (LGA). As a result, dynamic studies using FDG, MPDX and TMSX were accomplished without serial arterial blood sampling. The variational Bayesian approach introduces nonnegative constraints to an algorithm based on independent component analysis which has been developed by my group. The approaches improved an estimation performance of a time history of radioactivity in arterial blood (pTAC), and it made an estimated blood volume image, which was another outcome of the algorithm, physiologically reliable. Other algorithm based on LGA is to estimate pTAC using the operational equation of LGA, for which the terms including pTAC were canceled out using pTAC is common among regions. This algorithm was sensitive for noise in PET data due to its mathematical framework. In order to realize reliable pTAC estimation, some data preprocessing procedures were developed using clustering based on a kinetics of administered radiopharmaceutical For the omission of reference region, a feasibility of voxel-based compartment model analysis was investigated. However, it was not practical due to bad noise statistics in voxel-based PET data. Then, total distribution volumes (VT) was estimated for each voxels to decrease the number of estimated rate constants using LGA. The VT estimates by LGA is underestimated under the existence of large noise in PET data. MAP based estimation approach was incorporated with LGA, and fast and statistically reliable voxel-based VT estimation was archived.
• New PET diagnosis of adenosine receptors in the brain, heart and skeletal muscle

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2004 -2006 

  Author : ISHIWATA Kiichi; ISHII Kenji; NARIAI Tadashi; MISHINA Masahiro; KIMURA Yuichi

   

  The purpose of the present study is to propose new PET diagnosis using [^<11>C]MPDX and [^<11>C]TMSX for imaging adenosine A_1 and A_<2A> receptors, respectively, in the brain, heart and muscle 1. By applying [^<11>C]MPDX-PET and [^<11>C]TMSX-PET to normal subjects, A_1 and A_<2A> receptors, respectively, was quantitatively measured by compartment and graphical analyses using dynamic PET scan and serial arterial blood data. 2. To avoiding invasive arterial blood sampling, a non-invasive quantitative method EPICA was successfully applied to both[^<11>C]MPDX-and [^<11>C]TMSX-PET. 3. In the patients with Alzheimer's disease, a significantly decreased binding of [^<11>C]MPDX was observed in the bilateral medial temporal cortex and left temporo-parietal cortex. The decreased binding pattern of [^<11>C]MPDX was different from hypometabolism. In the patients with temporal lobe epilepsy, binding of [^<11>C]MPDX was significantly decreased in the mesial temporal lobe of focus side outside the hippocampus, but increased in the frontal cortex of focus side. 4. In the patients with Parkinson's disease whose the left-side dopamine transporter was more decreased than the right side one, the dopamine D_2 receptors bindings was increased bilaterally, while the adenosine A_<2A> receptor was decreased on the left side. 5. Following animal experiments, adenosine A_<2A> receptors in the heart and muscle were quantitatively evaluated in normal subjects. Adenosine A_<2A> receptor binding in the cardiac and skeletal muscles was greater in the endurance-trained men than in the untrained men. We concluded that [^<11>C]MPDX-PET and [^<11>C]TMSX-PET provides diagnostic tools of the physiological and pathological states of various diseases in term of adenosine receptors.
• Detailed imaging of cerebral glucose metabolism for dementia diagnosis including omission of arterial blood sampling and correction of partial volume effect

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2004 -2005 

  Author : KIMURA Yuishi; ODA Keiichi; ISHII Kenji; ISHIWATA Kiichi

   

  MAP-based estimation algorithm could be archived which had better performance than ordinary likelihood approach for imaging of cerebral glucose metabolism. This algorithm could avoid an iterative computation and searching an optimal points, therefore it was free from dependency to an initial value and misconvergence. The results from normal and Alzheimer cases were coincided with ROI-based analysis, and the computation required only 30 minutes. Also, a new algorithm for omission arterial blood sampling based on independent component analysis was established, and using the both algorithm, the practical scheme for glucose metabolism imaging without arterial blood sampling was realized in a shorter measurement duration than usual. On a correction of partial volume effect (PVE), a algorithm using a statistical modeling and morphological operation was developed. The algorithm first segmented a MRI image to some anatomical structures based on voxel values, then a morphological operations were applied to incorporate three-dimensional structure of brain anatomy. Finally, PVE was compensated using a linear estimation assuming regional voxel values in white matter and gray matter were common. When the PVE algorithm was applied to PET data of PK11195, a ligand for peripheral benzodiazepine receptors, PVE could be corrected well.
• 脳シグマ受容体を指標にした加齢・神経変性疾患・脳腫瘍の新しいPET診断法

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 2001 -2003 

  Author : 石渡 喜一; 木村 裕一; 成相 直; 石井 賢二

   

  我々は独自に開発した放射性薬剤の[^<11>C]SA4503を用いて、平成12年度に世界に先駆けてPETによる健常者の脳シグマ1受容体の画像化に成功した。本課題では、1)健常者を対象にこの[^<11>C]SA4503-PET診断法を確立し、2)幾つかの脳疾患に応用することにより新しい診断法の意義を明らかにし、3)また、シグマ1受容体に関する基礎研究も遂行することを目的としている。4)更なる展開を図るため、臨床的に汎用性が期待される^<18>F標識リガンドやシグマ2受容体サブタイプ選択的な新規リガンド開発も目指した。主要な結果は以下の通りである。 1.一般に神経受容体は加齢にともない減少するが、シグマ1受容体はラットやサルでは増加し、ヒトでは増加傾向を示した。 2.アルツハイマー病の診断に[^<18>F]FDG-PETは有用であるが、[^<11>C]SA4503-PETは変性の指標としてより鋭敏であった。 3.パーキンソン病診断では、ドパミントランスポータの減少と同様に、シグマ1受容体の結合能低下が認められた。 4.ハロペリドールのシグマ1受容体占拠率を初めて明らかにした。向精神薬の薬効とシグマ1受容体結合能の関連性の検討が可能になった。 5.統合失症などの精神疾患への応用も期待された。 6.[^<11>C]SA4503-PETは下腹部の癌診断への可能性が明らかになった。 7.[^<11>C]SA4503の脳集積はP糖タンパク質の基質にはならないことが明らかになった。 8.新たに検討した薬剤の中で、[^<18>F]FE-SA5845は、癌の診断薬としても期待できることが明らかになった。
• High speed algorithm for statistically reliable parametric image in positron emission tomography without continuous arterial blood sampling

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2001 -2002 

  Author : KIMURA Yuichi; ODA Keiichi; ISHII Kenji; MATANI Ayumu

   

  Voxel-based kinetic analysis in PET can visualize various functionalities in a living tissue. Major drawbacks in formation of an parametic image are bad noise statistics in voxel-based PET data. A large amount of voxels in PET causes a huge calculation time, and it makes formation of a parametric image inpractical. The statistical model-based clustering algorithm of CAKS (Clustering Analysis for Kinetics) is proposed to categorize voxels whose PET data has a similar shape and has similar functionalities. In CAKS, PET data was projected in a feature space and mixture Gaussian model was ulitized. As results, a parametric image can be formed in 30 minutes and the estimates were correspond to the estimates by an ordinal ROI-based estimation. Arterial blood sampling is other problem to apply CAKS in a clinical situation. The spatial distribution of tissue and blood vessel in a brain is distinguishable, and statistical algorithm for a blind separation of independent component analysis was applicable. After specialy designed data preprocessing schemes to emphasize the difference between spatial distribution of vessel and tissue, a proposed algorithm can estimate time course of activity in arterial blood and it corresponded to a measured time activity curve.
• Investigation of Basal Ganglia Function and Intrinsic Dopamine Release by Positron Emission Tomography

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2000 -2001 

  Author : ISHII Kenji; KIMURA Yuichi; ISHIWATA Kiichi

   

  To investigate the role of nigrostriatal dopamine system in performing a skilled complex motor task without leaning such as writing, we measured endogenous dopamine release in human brain with ^<13>C-raclopride (RAC) and PET. We studied six right-handed healthy volunteers (ages 22.0±1.7 years). After an intravenous injection of RAC, a 60 minites dynamic scan was performed. Each subject participated in RAC-PET twice on the same day (scan interval 145.0±35.2 minutes) under two different conditions ; during hand writing and at rest in balanced order. In the writing condition, the subjects was asked to dictate sentences as quick as possible on a computer-controlled writing pad with pen tool using their right hand. In resting condition, the subject was asked to watch the display without any movement. Endgeneous dopamine release was estimated indirectly based on the occupancy model, from the difference of the binding potential (BP) of PAC in two different conditions. The same subjects also participated in H_<2>^<15>O-PET with the same paradigm to evaluate the regional cerebral activation with the task in terms of regional cerebral blood flow change. The left striatum was activated significantly with H_<2>^<15>5O-PET study with writing task. In the same region, the binding potentials of RAC was significantly reduced by dictation task, thus, the intrinsic dopamine release was considered to be accelerated by the task. The activated region located in the ventro-caudal portion of the putamen which we previosly reported to be corresponding to hand area in the sometotopic organization in the basal ganglia. This result demonstrated the ability of indirect measurement method of intrinsic dopamine release by RAC-PET in physiological condition. Our results are the first report of activation of dopaminergic neurons by a skilled voluntary monements.
• 高信頼度核医学パラメトリック画像の高速生成手法に関する研究

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 1998 -1999 

  Author : 木村 裕一

   

  前年度において確立した、2-コンパートメント-2-パラメータモデルを対象とした本手法を、今年度は3-コンパートメントモデルへ拡大した。 3-コンパートメントモデルにおいては、組織放射能曲線(tTAC)の形状を決定するパラメータは、k_2,k_3の二つとなることから、tTACの特徴付ける2種類のRを実データから算出することによって、クラスタリングを行った。 その結果、人脳のFDGについて、妥当なパラメトリック画像を2分程度の計算時間で作成することができた。また計算機シミュレーションによれば、本手法は通常のROIを用いた動態解析とほぼ同等の推定精度を有することが判った。 3-コンパートメントモデルは、PETにおける典型的な放射性薬剤であるFDGを記述する動態モデルであり、これへの適用の拡大は、本手法の実用性を高めるものである。
• 高齢者の行動検知とその評価に関する研究

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 1998 -1999 

  Author : 田村 俊世; 木村 裕一; 戸川 達男

   

  本研究の目的は,屋内外の行動を各種センサを用いて測定し,生活習慣の定量化を試みるものである.屋内で近赤外線センサやマグネティクセンサを用いて人の挙動を逐次記録し,屋外では時計型の加速度センサを用いて測定を試みる.今年度は,屋内の行動に着目し以下の2つのシステムを構築した.1)家具調度や電化製品を設置してある場所に近赤外センサ,マグネットセンサを設置し,機器を使用する時間,頻度を測定して行動時間,行動パターンを評価した.2)生活排水に着目し,水道の蛇口や排水溝外部に温度センサを装着し温度変化から水道水の利用を検知した.今年度は特に台所の生活排水の測定を連続的に行った.その結果,1)近赤外センサでヒトの大まかな行動は検知できた.しかし,暖房器具使用時の誤差などもあり1つのセンサでの行動検知は精度的に問題が残った.近赤外センサ,マグネットセンサや環境測定のための湿度,室温センサや二酸化炭素センサなと複数のセンサを用いることにより行動情報を正確に得ることができた.約1ケ月にわたる測定では,7日ごとの生活パターンが示された.2)生活排水温度変化ののおおまかな測定により食事を含む台所での行動のパターンが示された.約1ケ月にわたる測定では,食事の開始時間,終了時間などの時刻の推定が可能であった.生活リズムの定量化として,次年度以降,多変量解析をおこなうことを検討する.今回のシステムは,測定対象者をなるべく拘束せず,かつデータ処理が容易であるので,次年度は高齢者,特に独居老人を対象に実験を試み,1日の行動パターンならびに食事時間の推移などについて検討する予定である.
• A study on imaging of thermal properties of the skin

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 1997 -1999 

  Author : TOGAWA Tatsuo; SAITOH Hirokazu; OTSUKA Kimio; KIMURA Yuichi

   

  The aim of this study is to develop a non-contact imaging system of emissivity and thermal inertia of the skin. In this study, results as follows have been achieved. The system consists of a thermal camera and a hood covering the object surface in which the temperature of its inside is controlled so as to realize a step change of the surface radiation. The emissivity can be estimated from the apparent change of radiation, and the thermal inertia can be estimated from the slope of increasing object surface temperature. The estimations can be performed at each pixel so that images of emissivity and thermal inertia of skin can be obtained. Observed emissivities were consistent with other measurement data including that of ours using high precision spot radiometer. Thermal inertia values were also consistent with other reports. Parallel relation between thermal inertia and blood flow of the skin was also observed. As an application of this method, the change in thermal inertia before and after arterial occlusion was studied, and we found that non-uniform thermal inertia image was observed together with a reactive hyperemia. This fact suggests that blood flow distribution just after an arterial occlusion is non-uniform. While the system could be used for such physiological studies, improvements of the measurement system were attempted so as to apply in clinical diagnosis. A modified system was proposed in that a radiation source with a mechanical shutter placed distant from the object is used instead of the hood. A preliminary study showed that the method is quite promising. Relating to this measurement principle and configuration of the system, a patent was applied.
• PET装置開発

  Date (from‐to) : 1999
• 運動生理学へのPETの応用

  Date (from‐to) : 1999
• Developement of PET instrumentation

  Date (from‐to) : 1999
• Application of PET for exercise physiology

  Date (from‐to) : 1999
• 核医学機能画像の高速生成手法に関する研究

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 1996 -1996 

  Author : 木村 裕一

   

  本研究では、核医学動態解析において、トレーサの体内での挙動を記述する際に使用されるコンパートメントモデルの高速な同定手法の構築を目的とした。高速なモデル同定が可能となれば従来行われている関心領域を設定してのモデル同定に比べて、遥かに空間分解能の高い画像を得ることが可能となり、より多くの臨床的知見が得られる可能性が考えられる。本研究では、フルオロデオキシグルコース(FDG)を用いた糖代謝に関する速度定数パラメータの画像と、フロマゼニール(FMZ)によるヘンゾジアゼヒンレセプターの分布画像の作成を対象とした。 FMZに関しては、線形化によってモデル同定の高速化を図っているLogan plot法と、従来通りの非線形計画方に基づく同定手法の一つである、マルケ-ト法との比較を行った。その結果両法は、正常脳組織、および癲癇の焦点,脳血管障害に起因する損傷部位いずれに対しても、ほぼ同一の結果が得られることを確認した。またシミュレーションによって、様々なモデルパラメータの範囲において同様の検討を行った結果、両法はほぼ一致した。演算時間ではLogan plot法は100倍以上高速であることから、Logan plot法は実用手法として妥当であると言える。 FDG に関しては、マルケ-ト法に対して 自提案の冗長重み付き積分法を比較した。冗長重み付き積分法は、マルケ-ト法の概ね100倍の速度でコンパートメントモデルの同定が可能であった。しかし一方で、入力データのノイズに対して、結果が数パーセント変動することが確認された。ノイズレベルに対する依存性は、実用上大きな問題であることから、今後の課題である。
• In vivo imaging of viscoelasticity and hardness of biological soft tissue using ultrasound.

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 1993 -1994 

  Author : YAMASHITA Yasuo; KIMURA Yuichi

   

  Changes in tissue elasticity are related to diffuse disease processes of living soft tissue. The goal of this study is to characterize tissue elasticity based on ultrasonic measurement of displacement and strain when the primary cardiac pulsation or the external mechanical force is applied to the soft tissue. A model is presented for the changes in tissue elasticity as a change of internal strain tensor, which results in variation in the Young's or shear modulus of elasticity. Mesurements are performed using real-time ultrasound and the sequences of RF echo signal returned from tissue are digitized to estimate local tissue displacement. In this paper the 2-dimensional distribution of internal displacement is estimated using the spatio-temporal derivative of RF echo envelope signals, from which components of internal strain tensor are computed. Experiments on tissue mimicking phantoms indicate that 2-dimensional fields of components of strain tensor can be estimated with the spatial resolution of 8mm*8mm. The distribution of the relative shear modulus based on strain images is reconstructed. In experiments with living soft tissue, such as liver in vivo, the relative shear modulus is large in less elastic regions. The elasticity of soft tissue can be characterized as the relative shear modulus computed from the local strain tenpor observed in the received RF echo signals.
• PET画像のデータ処理
• 医用画像処理 (PET, MRI, CT等)
• 統計数理処理の医用データへの応用
• 1.Forming parametric images in PET kinetics analysis 2.Image processing in PET

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