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KATOH CHIETSUGU
Faculty of Health Sciences　Health Sciences　Biomedical Science and Engineering
Professor
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Last Updated :2024/05/09

Researcher Profile and Settings

Affiliation

  • Faculty of Health Sciences　Health Sciences　Biomedical Science and Engineering

Job Title

  • Professor

Degree

  • Mar.1995 Ph.D.degree (Hokkaido University)（Hokkaido University）

URL

Research funding number

  • 10292012

J-Global ID

Profile

  • 2014 Hokkaido University Graduate School of Medicine

    Faculty of Health Sciences Biomedical Sciences Engineering

    Professor

Research Interests

  • 医用画像解析   核医学   PET   Medical Image Alalysis   Nuclear Medicine   Deep learning   

Research Areas

  • Life sciences / Radiology

Educational Organization

Academic & Professional Experience

  • 2012/04 - Today Faculty of Health sciences, Hokkaido University Graduate school Professor
  • 2008 北海道大学大学院保健科学研究院 准教授
  • 2004 北海道大学助教授(医学部保健学科検査技術学専攻) 助教授
  • 1997 - 1998 トゥルク大学PETセンター 研究員
  • 1997 北海道大学医学部核医学講座 助手

Education

  •        - 1987  Hokkaido University  School of Medicine
  •        - 1981  Nagoya University  School of Engineering

Association Memberships

  • JAPANESE SOCIETY FOR MEDICAL AND BIOLOGICAL ENGINEERING   SOCIETY OF NUCLEAR MEDICINE AND MOLECULAR IMAGING   JAPANESE SOCIETY OF NUCLEAR MEDICINE   JAPAN RADIOLOGICAL SOCIETY   

Research Activities

Published Papers

  • Ayaka Maruo, Keiichi Magota, Yamato Munakata, Kenji Hirata, Chietsugu Katoh
    Annals of Nuclear Medicine 0914-7187 2024/03/13 [Refereed][Not invited]
  • Keisuke Kawauchi, Mui Saito, Kentaro Nishigami, Chietsugu Katoh
    Nuclear Medicine Communications 44 (11) 1029 - 1037 0143-3636 2023/08/30 [Refereed]
     
    Purpose Quantitative images of metabolic activity can be derived through dynamic PET. However, the conventional approach necessitates invasive blood sampling to acquire the input function, thus limiting its noninvasive nature. The aim of this study was to devise a system based on convolutional neural network (CNN) capable of estimating the time-radioactivity curve of arterial plasma and accurately quantify the cerebral metabolic rate of glucose (CMRGlc) directly from PET data, thereby eliminating the requirement for invasive sampling. Methods This retrospective investigation analyzed 29 patients with neurological disorders who underwent comprehensive whole-body 18F-FDG-PET/CT examinations. Each patient received an intravenous infusion of 185 MBq of 18F-FDG, followed by dynamic PET data acquisition and arterial blood sampling. A CNN architecture was developed to accurately estimate the time-radioactivity curve of arterial plasma. Results The CNN estimated the time-radioactivity curve using the leave-one-out technique. In all cases, there was at least one frame with a prediction error within 10% in at least one frame. Furthermore, the correlation coefficient between CMRGlc obtained from the sampled blood and CNN yielded a highly significant value of 0.99. Conclusion The time-radioactivity curve of arterial plasma and CMRGlc was determined from 18F-FDG dynamic brain PET data using a CNN. The utilization of CNN has facilitated noninvasive measurements of input functions from dynamic PET data. This method can be applied to various forms of quantitative analysis of dynamic medical image data.
  • Kazunari Maekawa, Atsushi B. Tsuji, Atsushi Yamashita, Aya Sugyo, Chietsugu Katoh, Minghui Tang, Kensaku Nishihira, Yoshisato Shibata, Chihiro Koshimoto, Ming-Rong Zhang, Ryuichi Nishii, Keiichiro Yoshinaga, Yujiro Asada
    Atherosclerosis 337 7 - 17 0021-9150 2021/11 [Refereed][Not invited]
  • Saaya Mori, Sakura Ishiguro, Satoru Miyazaki, Torahiko Okubo, Ryosuke Omori, Ayako Kai, Kyohei Sugiyama, Airi Kawashiro, Masato Sumi, Jeewan Thapa, Shinji Nakamura, Chietsugu Katoh, Hiroyuki Yamaguchi
    Research in Microbiology 103864 - 103864 0923-2508 2021/07 [Refereed][Not invited]
  • Masanao Naya, Tadao Aikawa, Osamu Manabe, Masahiko Obara, Kazuhiro Koyanagawa, Chietsugu Katoh, Nagara Tamaki
    Heart and Vessels 36 (7) 917 - 923 0910-8327 2021/07 [Refereed][Not invited]
     
    Endothelin-1 contributes to the constrictor response of the coronary arteries in patients with ischemia with normal coronary arteries. There is thus increasing evidence that endothelin-1 plays a role in coronary microvascular dysfunction (CMD). We investigated whether elevated endothelin-1 is associated with CMD in patients with coronary artery disease (CAD). We prospectively studied 49 consecutive CAD patients with 1- or 2-vessel disease (age 71 ± 10 years, 43 males). Myocardial blood flow (MBF) was measured by 15O-water PET/CT at rest and during stress, and the coronary flow reserve (CFR) was calculated by dividing the stress MBF by the rest MBF. A CFR of less than 2.0 in non-obstructive regions was defined as a marker of CMD. Eighteen out of 49 (37%) CAD patients had CMD. Endothelin-1 in patients with CMD was significantly higher than in those without CMD (2.27 ± 0.81 vs. 1.64 ± 0.48 pg/mL, P = 0.001). Accordingly, univariate ROC analysis showed that the continuous endothelin-1 levels significantly discriminated between the presence and absence of CMD (area under the curve = 0.746 [95%CI 0.592-0.899]). The dichotomous treatment of elevated endothelin-1 as 1.961 pg/mL or more yielded the optimal discriminatory capacity, with a sensitivity of 72.2% and a specificity of 71.0%. High endothelin-1 was still a significant predictor of CMD after adjusting for diabetes mellitus (odds ratio = 6.64 [1.75-25.22], P = 0.005). Endothelin-1 is associated with CMD in non-obstructive territories in patients with CAD, suggesting that endothelin-1 is a potential target for treating CMD in CAD patients.
  • Masashi Kawakami, Kenji Hirata, Sho Furuya, Kentaro Kobayashi, Hiroyuki Sugimori, Keiichi Magota, Chietsugu Katoh
    Frontiers in Medicine 7 616746 - 616746 2020/12/23 [Refereed]
     
    Deep learning technology is now used for medical imaging. YOLOv2 is an object detection model using deep learning. Here, we applied YOLOv2 to FDG-PET images to detect the physiological uptake on the images. We also investigated the detection precision of abnormal uptake by a combined technique with YOLOv2. Using 3,500 maximum intensity projection (MIP) images of 500 cases of whole-body FDG-PET examinations, we manually drew rectangular regions of interest with the size of each physiological uptake to create a dataset. Using YOLOv2, we performed image training as transfer learning by initial weight. We evaluated YOLOv2's physiological uptake detection by determining the intersection over union (IoU), average precision (AP), mean average precision (mAP), and frames per second (FPS). We also developed a combination method for detecting abnormal uptake by subtracting the YOLOv2-detected physiological uptake. We calculated the coverage rate, false-positive rate, and false-negative rate by comparing the combination method-generated color map with the abnormal findings identified by experienced radiologists. The APs for physiological uptakes were: brain, 0.993; liver, 0.913; and bladder, 0.879. The mAP was 0.831 for all classes with the IoU threshold value 0.5. Each subset's average FPS was 31.60 ± 4.66. The combination method's coverage rate, false-positive rate, and false-negative rate for detecting abnormal uptake were 0.9205 ± 0.0312, 0.3704 ± 0.0213, and 0.1000 ± 0.0774, respectively. The physiological uptake of FDG-PET on MIP images was quickly and precisely detected using YOLOv2. The combination method, which can be utilized the characteristics of the detector by YOLOv2, detected the radiologist-identified abnormalities with a high coverage rate. The detectability and fast response would thus be useful as a diagnostic tool.
  • Keisuke Kawauchi, Sho Furuya, Kenji Hirata, Chietsugu Katoh, Osamu Manabe, Kentaro Kobayashi, Shiro Watanabe, Tohru Shiga
    BMC Cancer 20 (1) 227 - 227 2020/12 [Refereed]
     
    Abstract Background As the number of PET/CT scanners increases and FDG PET/CT becomes a common imaging modality for oncology, the demands for automated detection systems on artificial intelligence (AI) to prevent human oversight and misdiagnosis are rapidly growing. We aimed to develop a convolutional neural network (CNN)-based system that can classify whole-body FDG PET as 1) benign, 2) malignant or 3) equivocal. Methods This retrospective study investigated 3485 sequential patients with malignant or suspected malignant disease, who underwent whole-body FDG PET/CT at our institute. All the cases were classified into the 3 categories by a nuclear medicine physician. A residual network (ResNet)-based CNN architecture was built for classifying patients into the 3 categories. In addition, we performed a region-based analysis of CNN (head-and-neck, chest, abdomen, and pelvic region). Results There were 1280 (37%), 1450 (42%), and 755 (22%) patients classified as benign, malignant and equivocal, respectively. In the patient-based analysis, CNN predicted benign, malignant and equivocal images with 99.4, 99.4, and 87.5% accuracy, respectively. In region-based analysis, the prediction was correct with the probability of 97.3% (head-and-neck), 96.6% (chest), 92.8% (abdomen) and 99.6% (pelvic region), respectively. Conclusion The CNN-based system reliably classified FDG PET images into 3 categories, indicating that it could be helpful for physicians as a double-checking system to prevent oversight and misdiagnosis.
  • 河上 壮志, 杉森 博行, 平田 健司, 孫田 惠一, 加藤 千恵次
    核医学技術 (NPO)日本核医学技術学会 40 (予稿集) 345 - 345 0289-100X 2020/10
  • Osamu Manabe, Ran Klein, Chietsugu Katoh, Keiichi Magota, Robert A. deKemp, Masanao Naya, Nagara Tamaki, Keiichiro Yoshinaga
    Nuclear Medicine Communications 41 (8) 768 - 775 0143-3636 2020/08 
    INTRODUCTION: Three-dimensional (3D) data acquisition is now standard on PET/computed tomography scanners. The aim of this study was to evaluate the repeatability of myocardial blood flow (MBF) estimation with rubidium-82 (Rb) 3D PET and to validate regional MBF measurements by comparison with two-dimensional (2D) PET. PATIENTS AND METHODS: Fifteen healthy individuals (31.6 ± 11.4 years old) were enrolled for the evaluation of the short-term repeatability of rest 3D MBF quantification. Another 19 healthy individuals (35.3 ± 12.6 years old) underwent rest and pharmacological stress PET using 2D and 3D data acquisition within a 1-month interval. The injected dose was 1500 MBq for 2D and 555 MBq for 3D PET acquisition. RESULTS: MBF at rest showed good repeatability [whole left ventricular MBF; 0.54 ± 0.13 vs. 0.52 ± 0.13 mL/min/g, P = 0.98]. Rest MBF, stress MBF, and myocardial flow reserve (MFR) were not significantly different between 3D and 2D data acquisition. 3D MBF correlated well with 2D MBF over a wide flow range for both whole left ventricular (r = 0.97, P < 0.0001) and regional values (r = 0.61, P < 0.0001). CONCLUSION: MBF measured with 3D PET showed very good test-retest repeatability. Whole left ventricular and regional MBF measurements obtained using lower Rb-dose 3D PET were highly correlated over a wide range with those from 2D PET. Therefore, MBF with 3D PET can be applied using a lower Rb dosage in clinical settings with reduced radiation exposure.
  • 河上 壮志, 平田 健司, 杉森 博行, 加藤 千恵次
    核医学技術 (NPO)日本核医学技術学会 39 (予稿集) 346 - 346 0289-100X 2019/10
  • Keisuke Kawauchi, Kenji Hirata, Chietsugu Katoh, Seiya Ichikawa, Osamu Manabe, Kentaro Kobayashi, Shiro Watanabe, Sho Furuya, Tohru Shiga
    Scientific reports 9 (1) 7192 - 7192 2019/05/10 [Refereed][Not invited]
     
    Patient misidentification in imaging examinations has become a serious problem in clinical settings. Such misidentification could be prevented if patient characteristics such as sex, age, and body weight could be predicted based on an image of the patient, with an alert issued when a mismatch between the predicted and actual patient characteristic is detected. Here, we tested a simple convolutional neural network (CNN)-based system that predicts patient sex from FDG PET-CT images. This retrospective study included 6,462 consecutive patients who underwent whole-body FDG PET-CT at our institute. The CNN system was used for classifying these patients by sex. Seventy percent of the randomly selected images were used to train and validate the system; the remaining 30% were used for testing. The training process was repeated five times to calculate the system's accuracy. When images for the testing were given to the learned CNN model, the sex of 99% of the patients was correctly categorized. We then performed an image-masking simulation to investigate the body parts that are significant for patient classification. The image-masking simulation indicated the pelvic region as the most important feature for classification. Finally, we showed that the system was also able to predict age and body weight. Our findings demonstrate that a CNN-based system would be effective to predict the sex of patients, with or without age and body weight prediction, and thereby prevent patient misidentification in clinical settings.
  • Osamu Manabe, Noriko Oyama-Manabe, Masanao Naya, Masahiko Obara, Yasuka Kikuchi, Tadao Aikawa, Yuuki Tomiyama, Hiroyuki Sugimori, Chietsugu Katoh, Nagara Tamaki, Toshihisa Anzai
    Cardiovascular Imaging Asia 3 (1) 8 - 8 2508-707X 2019
  • Tadao Aikawa, Masanao Naya, Masahiko Obara, Osamu Manabe, Keiichi Magota, Kazuhiro Koyanagawa, Naoya Asakawa, Yoichi M Ito, Tohru Shiga, Chietsugu Katoh, Toshihisa Anzai, Hiroyuki Tsutsui, Venkatesh L Murthy, Nagara Tamaki
    Cardiovascular research 115 (1) 119 - 129 2019/01/01 [Refereed][Not invited]
     
    Aims: Coronary flow reserve (CFR) is an integrated measure of the entire coronary vasculature, and is a powerful prognostic marker in coronary artery disease (CAD). The extent to which coronary revascularization can improve CFR is unclear. This study aimed to evaluate the impact of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) on CFR in patients with stable CAD. Methods and results: In a prospective, multicentre observational study, CFR was measured by 15O-water positron emission tomography as the ratio of stress to rest myocardial blood flow at baseline and 6 months after optimal medical therapy (OMT) alone, PCI, or CABG. Changes in the SYNTAX and Leaman scores were angiographically evaluated as indicators of completeness of revascularization. Follow-up was completed by 75 (25 OMT alone, 28 PCI, and 22 CABG) out of 82 patients. The median SYNTAX and Leaman scores, and baseline CFR were 14.5 [interquartile range (IQR): 8-24.5], 5.5 (IQR: 2.5-12.5), and 1.94 (IQR: 1.67-2.66), respectively. Baseline CFR was negatively correlated with the SYNTAX (ρ = -0.40, P < 0.001) and Leaman scores (ρ = -0.33, P = 0.004). Overall, only CABG was associated with a significant increase in CFR [1.67 (IQR: 1.14-1.96) vs. 1.98 (IQR: 1.60-2.39), P < 0.001]. Among patients with CFR <2.0 (n = 41), CFR significantly increased in the PCI [1.70 (IQR: 1.42-1.79) vs. 2.21 (IQR: 1.78-2.49), P = 0.002, P < 0.001 for interaction between time and CFR] and CABG groups [1.28 (IQR: 1.13-1.80) vs. 1.86 (IQR: 1.57-2.22), P < 0.001]. The reduction in SYNTAX or Leaman scores after PCI or CABG was independently associated with the percent increase in CFR after adjusting for baseline characteristics (P = 0.012 and P = 0.011, respectively). Conclusion: Coronary revascularization ameliorated reduced CFR in patients with obstructive CAD. The degree of improvement in angiographic CAD burden by revascularization was correlated with magnitude of improvement in CFR.
  • 15O-水心筋血流PETにおけるMonte Carlo scaling複合型SSS散乱補正の検討
    孫田 惠一, 志賀 哲, 真鍋 治, 納谷 昌直, 相川 忠夫, 新山 大樹, 平田 健司, 加藤 千恵次, 藤田 勝久, 玉木 長良
    核医学 (一社)日本核医学会 55 (Suppl.) S212 - S212 0022-7854 2018/11 [Refereed][Not invited]
  • Abiko K, Shiga T, Katoh C, Hirata K, Kuge Y, Kobayashi K, Ikeda S, Ikoma K
    Brain Inj. 32 (11) 1367 - 1372 2018/11 [Refereed][Not invited]
     
    OBJECTIVE: Cerebral metabolism may play a significant role in neurobehavioural disability following traumatic brain injury (TBI). In this study, we examined the relationship between intelligence quotient (IQ) and the cerebral metabolic rate of oxygen (CMRO2) in the lateral prefrontal cortex, which was measured by 15O-labelled gas positron emission tomography (PET), in patients with TBI. MATERIALS AND METHODS: The subjects were 12 patients (eight males and four females) who suffered from neurobehavioural disability following TBI. Their mean age was 33.3 years. The cause of injury was traffic accidents in all patients and the mean period after injury was 44.8 months. These patients underwent 15O-labelled gas PET and tests using either the Wechsler Adult Intelligence Scale-Revised (WAIS-R) or the Wechsler Intelligence Scale for Children-Revised (WISC-R). Pearson's correlation between CMRO2 and total IQ (TIQ) was calculated. RESULTS: A statistically significant correlation was observed between TIQ and CMRO2 in the right Brodmann areas (BAs) 44 and 45. The lower the WAIS score, the higher the CMRO2 in both areas. CONCLUSION: Neurological function negatively correlated with the metabolism of oxygen. It was possible that changes in brain networks increased the neuronal activity in the undamaged areas and that the increased activity compensated for the function decline.
  • Masahiko Obara, Masanao Naya, Noriko Oyama-Manabe, Tadao Aikawa, Yuuki Tomiyama, Tsukasa Sasaki, Yasuka Kikuchi, Osamu Manabe, Chietsugu Katoh, Nagara Tamaki, Hiroyuki Tsutsui
    Medicine 97 (27) e11354  2018/07 [Refereed][Not invited]
     
    We have developed the method for dynamic 320-row multidetector computed tomography (MDCT)-derived quantitative coronary flow reserve (CFRCT) and hyperemic myocardial blood flow (MBFCT). We evaluated diagnostic value of CFRCT and hyperemic MBFCT for detecting obstructive coronary artery disease (CAD) in per-patient and per-vessel analysis, and their relations with the severity of CAD burden.Adenosine stressed and rest dynamic myocardial perfusion MDCT were prospectively performed in patients with known or suspected CAD. Per-patient and per-vessel MBFCT were estimated from dynamic perfusion images in rest and hyperemic phases, and per-patient and per-vessel CFRCT were calculated from the ratio of rest and hyperemic MBFCT. Degree of stenosis was evaluated by coronary CT angiography (CTA) and invasive coronary angiography (ICA). Obstructive stenosis was defined as ≥70% stenosis in ICA. CAD burden with MDCT was calculated by logarithm transformed coronary artery calcium (CAC) score and the CTA-adapted Leaman risk score (CT-LeSc). A logistic regression analysis was used to measure the receiver-operating characteristic curve and corresponding area under the curve (AUC) for the detection of obstructive CAD.Twenty-seven patients and 81 vessels were eligible for this study. Sixteen patients had obstructive CAD, and 31 vessels had obstructive stenosis. Using an optimal cutoff, the CFRCT and hyperemic MBFCT had the moderate diagnostic values in per-patient (AUC = 0.89 and 0.86, respectively) and per-vessel (AUC = 0.79 and 0.76, respectively). Per-patient CFRCT and hyperemic MBFCT exhibited a moderate inverse correlation with CAC score and the CT-LeSc.Per-patient and per-vessel CFRCT as well as hyperemic MBFCT had moderate diagnostic value for detecting obstructive CAD. These per-patient values exhibited a moderate inverse correlation with CAD burden. CFRCT and hyperemic MBFCT might add quantitative functional information for evaluating patients with CAD.
  • Strategy to develop convolutional neural network-based classifier for diagnosis of whole-body FDG PET images
    Keisuke Kawauchi, Kenji Hirata, Seiya Ichikawa, Osamu Manabe, Kentaro Kobayashi, Shiro Watanabe, Miki Haseyama, Takahiro Ogawa, Ren Togo, Tohru Shiga, Chietsugu Katoh
    Society of Nuclear Medicine and Molecular Imaging Annual Meeting (SNMMI) 2018/06 [Refereed][Not invited]
  • Yuji Hiroshima, Osamu Manabe, Masanao Naya, Yuuki Tomiyama, Keiichi Magota, Masahiko Obara, Tadao Aikawa, Noriko Oyama-Manabe, Keiichiro Yoshinaga, Kenji Hirata, Markus Kroenke, Nagara Tamaki, Chietsugu Katoh
    Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology 37 (4) 463 - 1125 0289-100X 2017/12/21 [Refereed][Not invited]
     
    BACKGROUND: 11C-hydroxyephedrine (HED) PET has been used to evaluate the myocardial sympathetic nervous system (SNS). Here we sought to establish a simultaneous approach for quantifying both myocardial blood flow (MBF) and the SNS from a single HED PET scan. METHODS: Ten controls and 13 patients with suspected cardiac disease were enrolled. The inflow rate of 11C-HED (K1) was obtained using a one-tissue-compartment model. We compared this rate with the MBF derived from 15O-H2O PET. In the controls, the relationship between K 1 from 11C-HED PET and the MBF from 15O-H2O PET was linked by the Renkin-Crone model. RESULTS: The relationship between K 1 from 11C-HED PET and the MBF from 15O-H2O PET from the controls' data was approximated as follows: K 1  =  (1 - 0.891 * exp(- 0.146/MBF)) * MBF. In the validation set, the correlation coefficient demonstrated a significantly high relationship for both the whole left ventricle (r = 0.95, P < 0.001) and three coronary territories (left anterior descending artery: r = 0.96, left circumflex artery: r = 0.81, right coronary artery: r =  0.86; P < 0.001, respectively). CONCLUSION: 11C-HED can simultaneously estimate MBF and sympathetic nervous function without requiring an additional MBF scan for assessing mismatch areas between MBF and SNS.
  • Osamu Manabe, Markus Kroenke, Tadao Aikawa, Atsuto Murayama, Masanao Naya, Atsuro Masuda, Noriko Oyama-Manabe, Kenji Hirata, Shiro Watanabe, Tohru Shiga, Chietsugu Katoh, Nagara Tamaki
    Journal of Nuclear Cardiology 1 - 10 1532-6551 2017/12/14 [Refereed][Not invited]
     
    Objective: FDG PET/CT plays a significant role in the diagnosis of inflammatory heart diseases and cardiac tumors. We attempted to determine the optimal FDG uptake threshold for volume-based analyses and to evaluate the relationship between the myocardial physiological uptake volume in FDG PET and several clinical factors. Methods: A total of 190 patients were retrospectively analyzed. The cardiac metabolic volume (CMV) was defined as a volume within the boundary determined by a threshold (SUVmean of blood pool × 1.5). Results: The SUVmean of the blood pool measured in the descending aorta (DA) (r = 0.86, intraclass correlation coefficient [ICC] = 0.93, P < 0.0001) and that in the left ventricle (LV) cavity (r = 0.87, ICC = 0.90, P < 0.0001) showed high inter-operator reproducibility. However, the SUVmean in the LV cavity showed a significant correlation with the CMV (P = 0.0002, r = 0.26). The CMV in the patients who fasted < 18 hours were significantly higher (49.7 ± 73.2 vs. 18.0 ± 53.8 mL, P = 0.0013) compared to the patients with > 18-hour fasting. The multivariate analysis demonstrated that only the fasting period > 18 hours was independently associated with CMV = 0. Conclusion: Our findings revealed that the DA is suitable to decide the threshold for the volume-based analysis. The fasting time was significantly associated with the cardiac FDG uptake.
  • Keiichi Magota, Tohru Shiga, Yukari Asano, Daiki Shinyama, Jinghan Ye, Amy E. Perkins, Piotr J. Maniawski, Takuya Toyonaga, Kentaro Kobayashi, Kenji Hirata, Chietsugu Katoh, Naoya Hattori, Nagara Tamaki
    JOURNAL OF NUCLEAR MEDICINE 58 (12) 2020 - 2025 0161-5505 2017/12 [Refereed][Not invited]
     
    In 3-dimensional PET/CT imaging of the brain with O-15-gas inhalation, high radioactivity in the face mask creates cold artifacts and affects the quantitative accuracy when scatter is corrected by conventional methods (e.g., single-scatter simulation [SSS] with tailfitting scaling [TFS-SSS]). Here we examined the validity of a newly developed scatter-correction method that combines SSS with a scaling factor calculated by Monte Carlo simulation (MCS-SSS). Methods: We performed phantom experiments and patient studies. In the phantom experiments, a plastic bottle simulating a face mask was attached to a cylindric phantom simulating the brain. The cylindric phantom was filled with F-18-FDG solution (3.8-7.0 kBq/mL). The bottle was filled with nonradioactive air or various levels of F-18-FDG (0-170 kBq/mL). Images were corrected either by TFS-SSS or MCS-SSS using the CT data of the bottle filled with nonradioactive air. We compared the image activity concentration in the cylindric phantom with the true activity concentration. We also performed 15O-gas brain PET based on the steady-state method on patients with cerebrovascular disease to obtain quantitative images of cerebral blood flow and oxygen metabolism. Results: In the phantom experiments, a cold artifact was observed immediately next to the bottle on TFS-SSS images, where the image activity concentrations in the cylindric phantom were underestimated by 18%, 36%, and 70% at the bottle radioactivity levels of 2.4, 5.1, and 9.7 kBq/mL, respectively. At higher bottle radioactivity, the image activity concentrations in the cylindric phantom were greater than 98% underestimated. For the MCS-SSS, in contrast, the error was within 5% at each bottle radioactivity level, although the image generated slight high-activity artifacts around the bottle when the bottle contained significantly high radioactivity. In the patient imaging with O-15(2) and (CO2)-O-15 inhalation, cold artifacts were observed on TFS-SSS images, whereas no artifacts were observed on any of the MCS-SSS images. Conclusion: MCS-SSS accurately corrected the scatters in O-15-gas brain PET when the 3-dimensional acquisition mode was used, preventing the generation of cold artifacts, which were observed immediately next to a face mask on TFS-SSS images. The MCS-SSS method will contribute to accurate quantitative assessments.
  • Keiichi Magota, Tohru Shiga, Yukari Asano, Daiki Shinyama, Jinghan Ye, Amy E. Perkins, Piotr J. Maniawski, Takuya Toyonaga, Kentaro Kobayashi, Kenji Hirata, Chietsugu Katoh, Naoya Hattori, Nagara Tamaki
    JOURNAL OF NUCLEAR MEDICINE 58 (12) 2020 - 2025 0161-5505 2017/12 [Refereed][Not invited]
     
    In 3-dimensional PET/CT imaging of the brain with O-15-gas inhalation, high radioactivity in the face mask creates cold artifacts and affects the quantitative accuracy when scatter is corrected by conventional methods (e.g., single-scatter simulation [SSS] with tailfitting scaling [TFS-SSS]). Here we examined the validity of a newly developed scatter-correction method that combines SSS with a scaling factor calculated by Monte Carlo simulation (MCS-SSS). Methods: We performed phantom experiments and patient studies. In the phantom experiments, a plastic bottle simulating a face mask was attached to a cylindric phantom simulating the brain. The cylindric phantom was filled with F-18-FDG solution (3.8-7.0 kBq/mL). The bottle was filled with nonradioactive air or various levels of F-18-FDG (0-170 kBq/mL). Images were corrected either by TFS-SSS or MCS-SSS using the CT data of the bottle filled with nonradioactive air. We compared the image activity concentration in the cylindric phantom with the true activity concentration. We also performed 15O-gas brain PET based on the steady-state method on patients with cerebrovascular disease to obtain quantitative images of cerebral blood flow and oxygen metabolism. Results: In the phantom experiments, a cold artifact was observed immediately next to the bottle on TFS-SSS images, where the image activity concentrations in the cylindric phantom were underestimated by 18%, 36%, and 70% at the bottle radioactivity levels of 2.4, 5.1, and 9.7 kBq/mL, respectively. At higher bottle radioactivity, the image activity concentrations in the cylindric phantom were greater than 98% underestimated. For the MCS-SSS, in contrast, the error was within 5% at each bottle radioactivity level, although the image generated slight high-activity artifacts around the bottle when the bottle contained significantly high radioactivity. In the patient imaging with O-15(2) and (CO2)-O-15 inhalation, cold artifacts were observed on TFS-SSS images, whereas no artifacts were observed on any of the MCS-SSS images. Conclusion: MCS-SSS accurately corrected the scatters in O-15-gas brain PET when the 3-dimensional acquisition mode was used, preventing the generation of cold artifacts, which were observed immediately next to a face mask on TFS-SSS images. The MCS-SSS method will contribute to accurate quantitative assessments.
  • Osamu Manabe, Masanao Naya, Tadao Aikawa, Masahiko Obara, Keiichi Magota, Markus Kroenke, Noriko Oyama-Manabe, Kenji Hirata, Daiki Shinyama, Chietsugu Katoh, Nagara Tamaki
    EJNMMI research 7 (1) 52 - 52 2017/12 [Refereed][Not invited]
     
    BACKGROUND: The quantification of myocardial blood flow (MBF) and coronary flow reserve (CFR) are useful approaches for evaluating the functional severity of coronary artery disease (CAD). 15O-water positron emission tomography (PET) is considered the gold standard method for MBF quantification. However, MBF measurements in 15O-water PET with three-dimensional (3D) data acquisition, attenuation correction using computed tomography (CT), and time of flight have not been investigated in detail or validated. We conducted this study to evaluate the diagnostic potential of MBF measurements using PET/CT for a comparison of a control group and patients suspected of having CAD. RESULTS: Twenty-four patients with known or suspected CAD and eight age-matched healthy volunteers underwent rest and pharmacological stress perfusion studies with 15O-water PET/CT. The whole and three regional (left anterior descending (LAD), left circumflex (LCX), and right coronary artery (RCA) territory) MBF values were estimated. The CFR was computed as the ratio of the MBF during adenosine triphosphate-induced stress to the MBF at rest. The inter-observer variability was assessed by two independent observers. PET/CT using a 15O-water dose of 500 MBq and 3D data acquisition showed good image quality. A strong inter-observer correlation was detected in both the whole MBF analysis and the regional analysis with high intra-class correlation coefficients (r > 0.90, p < 0.001). Regional MBF at rest (LAD, 0.82 ± 0.15 ml/min/g; LCX, 0.83 ± 0.17 ml/min/g; RCA, 0.71 ± 0.20 ml/min/g; p = 0.74), MBF at stress (LAD, 3.77 ± 1.00 ml/min/g; LCX, 3.56 ± 1.01 ml/min/g; RCA, 3.27 ± 1.04 ml/min/g; p = 0.62), and CFR (LAD, 4.64 ± 0.90; LCX, 4.30 ± 0.64; RCA, 4.64 ± 0.96; p = 0.66) of the healthy volunteers showed no significant difference among the three regions. The global CFR of the patients was significantly lower than that of the volunteers (2.75 ± 0.81 vs. 4.54 ± 0.66, p = 0.0002). The regional analysis of the patients demonstrated that the CFR tended to be lower in the stenotic region compared to the non-stenotic region (2.43 ± 0.81 vs. 2.95 ± 0.92, p = 0.052). CONCLUSIONS: 15O-water PET/CT with 3D data acquisition can be reliably used for the quantification of functional MBF and CFR in CAD patients.
  • Kagari Abiko, Katsunori Ikoma, Tohru Shiga, Chietsugu Katoh, Kenji Hirata, Yuji Kuge, Kentaro Kobayashi, Nagara Tamaki
    EJNMMI Research 7 (1) 28 - 28 2191-219X 2017/12/01 [Refereed][Not invited]
     
    Background: Traumatic brain injury (TBI) causes brain dysfunction in many patients. Using C-11 flumazenil (FMZ) positron emission tomography (PET), we have detected and reported the loss of neuronal integrity, leading to brain dysfunction in TBI patients. Similarly to FMZ PET, I-123 iomazenil (IMZ) single photon emission computed tomography (SPECT) is widely used to determine the distribution of the benzodiazepine receptor (BZR) in the brain cortex. The purpose of this study is to examine whether IMZ SPECT is as useful as FMZ PET for evaluating the loss of neuronal integrity in TBI patients. The subjects of this study were seven patients who suffered from neurobehavioral disability. They underwent IMZ SPECT and FMZ PET. Nondisplaceable binding potential (BPND) was calculated from FMZ PET images. The uptake of IMZ was evaluated on the basis of lesion-to-pons ratio (LPR). The locations of low uptake levels were visually evaluated both in IMZ SPECT and FMZ PET images. We compared FMZ BPND and (LPR-1) of IMZ SPECT. Results: In the visual assessment, FMZ BPND decreased in 11 regions. In IMZ SPECT, low uptake levels were observed in eight of the 11 regions. The rate of concordance between FMZ PET and IMZ SPECT was 72.7%. The mean values IMZ (LPR-1) (1.95 ± 1.01) was significantly lower than that of FMZ BPND (2.95 ± 0.80 mL/mL). There was good correlation between FMZ BPND and IMZ (LPR-1) (r = 0.80). Conclusions: IMZ SPECT findings were almost the same as FMZ PET findings in TBI patients. The results indicated that IMZ SPECT is useful for evaluating the loss of neuronal integrity. Because IMZ SPECT can be performed in various facilities, IMZ SPECT may become widely adopted for evaluating the loss of neuronal integrity.
  • Tadao Aikawa, Masanao Naya, Masahiko Obara, Noriko Oyama-Manabe, Osamu Manabe, Keiichi Magota, Yoichi M Ito, Chietsugu Katoh, Nagara Tamaki
    European journal of nuclear medicine and molecular imaging 44 (11) 1897 - 1905 2017/10 [Refereed][Not invited]
     
    PURPOSE: This investigation aimed to identify significant predictors of regional sympathetic denervation quantified by 11C-hydroxyephedrine (HED) positron emission tomography (PET) in patients with heart failure with preserved left ventricular ejection fraction (HFpEF). METHODS: Included in the study were 34 patients (age 63 ± 15 years, 23 men) with HFpEF (left ventricular ejection fraction ≥40%) and 11 age-matched volunteers without heart failure. Cardiac magnetic resonance imaging was performed to measure left ventricular size and function, and the extent of myocardial late gadolinium enhancement (LGE). 11C-HED PET was performed to quantify myocardial sympathetic innervation that was expressed as a 11C-HED retention index (RI, %/min). To identify predictors of regional 11C-HED RI in HFpEF patients, we propose a multivariate mixed-effects model for repeated measures over segments with an unstructured covariance matrix. RESULTS: Global 11C-HED RI was significantly lower and more heterogeneous in HFpEF patients than in volunteers (P < 0.01 for all). Regional 11C-HED RI was correlated positively with systolic wall thickening (r = 0.42, P < 0.001) and negatively with the extent of LGE (r = -0.43, P < 0.001). Segments in HFpEF patients with a large extent of LGE had the lowest regional 11C-HED RI among all segments (P < 0.001 in post hoc tests). Multivariate analysis demonstrated that systolic wall thickening and the extent of LGE were significant predictors of regional 11C-HED RI in HFpEF patients (both P ≤ 0.001). CONCLUSION: Regional sympathetic denervation was associated with contractile dysfunction and fibrotic burden in HFpEF patients, suggesting that regional sympathetic denervation may provide an integrated measure of myocardial damage in HFpEF.
  • 左室収縮が保持された心不全における11C-HED PETを用いた局所心筋交感神経分布の検討
    相川 忠夫, 納谷 昌直, 小原 雅彦, 真鍋 徳子, 真鍋 治, 小梁川 和宏, 孫田 恵一, 伊藤 陽一, 志賀 哲, 加藤 千恵次, 玉木 長良
    核医学 (一社)日本核医学会 54 (Suppl.) S174 - S174 0022-7854 2017/09 [Refereed][Not invited]
  • Tohru Shiga, Atsuro Suzuki, Kotarou Sakurai, Tsugiko Kurita, Wataru Takeuchi, Takuya Toyonaga, Kenji Hirata, Keiji Kobashi, Chietsugu Katoh, Naoki Kubo, Nagara Tamaki
    CLINICAL NUCLEAR MEDICINE 42 (9) 663 - 668 0363-9762 2017/09 [Refereed][Not invited]
     
    Purpose We developed a prototype CdTe SPECT system with 4-pixel matched collimator for brain study. This system provides high-energy-resolution (6.6%), high-sensitivity (220 cps/MBq/head), and high-spatial-resolution images. The aim of this study was to evaluate dual-isotope study of CBF and central benzodiazepine receptor (BZR) images using Tc-99m-ECD and I-123-IMZ with the new SPECT system in patients with epilepsy comparing with single-isotope study using the conventional scintillation gamma camera. Methods This study included 13 patients with partial epilepsy. The BZR images were acquired at 3 hours after I-123-IMZ injection for 20 minutes. The images of IMZ were acquired with a conventional 3-head scintillation gamma camera. After BZR image acquisition with the conventional camera, Tc-99m-ECD was injected, and CBF and BZR images were acquired simultaneously 5 minutes after ECD injection with the new SPECT system. The CBF images were also acquired with the conventional camera on separate days. The findings were visually analyzed, and 3D-SSP maximum Z scores of lesions were compared between the 2 studies. Results There were 47 abnormal lesions on BZR images and 60 abnormal lesions on CBF images in the single-isotope study with the conventional camera. Dual-isotope study with the new system showed concordant abnormal findings of 46 of 47 lesions on BZR and 54 of 60 lesions on CBF images with the single-isotope study with the conventional camera. There was high agreement between the 2 studies in both BZR and CBF findings (Cohen values = 0.96 for BZR and 0.78 for CBF). In semiquantitative analysis, maximum Z scores of dual-isotope study with the new system strongly correlated with those of single-isotope study with the conventional camera (BZR: r = 0.82, P < 0.05, CBF: r = 0.87, P < 0.05). Conclusions Our new SPECT system permits dual-isotope study for pixel-by-pixel analysis of CBF and BZR information with the same pathophysiological condition in patients with epilepsy.
  • Regional interaction between myocardial sympathetic denervation, contractile dysfunction, and fibrosis in heart failure with preserved ejection fraction: 11C-hydroxyephedrine PET study.
    Aikawa T, Naya M, Obara M, Oyama-Manabe N, Manabe O, Magota K, Ito YM, Katoh C, Tamaki N
    Eur J Nucl Med Mol Imaging. 26 2017/06 [Refereed][Not invited]
  • Tadao Aikawa, Masanao Naya, Masahiko Obara, Osamu Manabe, Yuuki Tomiyama, Keiichi Magota, Satoshi Yamada, Chietsugu Katoh, Nagara Tamaki, Hiroyuki Tsutsui
    Journal of nuclear medicine : official publication, Society of Nuclear Medicine 58 (5) 784 - 790 2017/05 [Refereed][Not invited]
     
    Diastolic dysfunction is important in the pathophysiology of heart failure with preserved ejection fraction (HFpEF). Sympathetic nervous hyperactivity may contribute to the development of diastolic dysfunction. The aim of this study was to determine the relationship between myocardial sympathetic innervation quantified by 11C-hydroxyephedrine PET and diastolic dysfunction in HFpEF patients. Methods: Forty-one HFpEF patients having an echocardiographic left ventricular ejection fraction of 40% or greater and 12 age-matched volunteers without heart failure underwent the echocardiographic examination and 11C-hydroxyephedrine PET. Diastolic dysfunction was classified into grades 0-3 by Doppler echocardiography. Myocardial sympathetic innervation was quantified using the 11C-hydroxyephedrine retention index (RI). The coefficient of variation of 17-segment RIs was derived as a measure of heterogeneity in myocardial 11C-hydroxyephedrine uptake. Results: Grade 2-3 diastolic dysfunction (DD2-3) was found in 19 HFpEF patients (46%). They had a significantly lower global RI (0.075 ± 0.018 min-1) than volunteers (0.123 ± 0.028 min-1, P < 0.001) and HFpEF patients with grade 0-1 diastolic dysfunction (DD0-1) (0.092 ± 0.024 min-1, P = 0.046). HFpEF patients with DD2-3 had the largest coefficient of variation of 17-segment RIs of the 3 groups (18.4% ± 7.7% vs. 14.1% ± 4.7% in HFpEF patients with DD0-1, P = 0.042 for post hoc tests). In multivariate logistic regression analysis, a lower global RI (odds ratio, 0.66 per 0.01 min-1; 95% confidence interval, 0.38-0.99; P = 0.044) was independently associated with the presence of DD2-3 in HFpEF patients. Conclusion: Myocardial sympathetic innervation was impaired in HFpEF patients and was associated with the presence of advanced diastolic dysfunction in HFpEF.
  • Atsuro Masuda, Keiichiro Yoshinaga, Masanao Naya, Osamu Manabe, Satoshi Yamada, Hiroyuki Iwano, Tatsuya Okada, Chietsugu Katoh, Yasuchika Takeishi, Hiroyuki Tsutsui, Nagara Tamaki
    EJNMMI research 6 (1) 41 - 41 2016/12 [Refereed][Not invited]
     
    BACKGROUND: Accelerated clearance of (99m)technetium-sestamibi (MIBI) has been observed after reperfusion therapy in patients with acute coronary syndrome (ACS), but the mechanisms have not been fully investigated. MIBI retention may depend on mitochondrial function. The clearance rate of (11)carbon-acetate reflects such mitochondrial functions as oxidative metabolism. The purpose of this study was to examine the mechanisms of accelerated MIBI clearance in ACS. We therefore compared it to oxidative metabolism estimated using (11)C-acetate positron emission tomography (PET). METHODS: Eighteen patients [mean age 69.2 ± 8.7 years, 10 males (56 %)] with reperfused ACS underwent MIBI single-photon emission computed tomography (SPECT), echocardiography, and (11)C-acetate PET within 3 weeks of the onset of ACS. MIBI images were obtained 30 min and 3 h after MIBI administration. Regional left ventricular (LV) function was evaluated by echocardiography. The measurement of oxidative metabolism was obtained through the mono-exponential fitting of the (11)C-acetate time-activity curve (k mono). RESULTS: Among 95 segments of reperfused myocardium, MIBI SPECT showed 64 normal segments (group N), 14 segments with accelerated MIBI clearance (group AC), and 17 segments with fixed defect (group F). Group AC showed lower k mono than group N (0.041 ± 0.009 vs 0.049 ± 0.010, p = 0.02). Group F showed lower k mono than group N (0.039 ± 0.012 vs 0.049 ± 0.010, p = 0.01). However, k mono was similar in group AC and group F (p = 0.99). CONCLUSIONS: Segments with accelerated MIBI clearance showed reduced oxidative metabolism in ACS. Loss of MIBI retention may be associated with mitochondrial dysfunction.
  • C-11 Hydroxyephedrine PET/CTを用いた心交感神経機能検出による心サルコイドーシス診断の有用性
    吉永 恵一郎, 真鍋 治, 大平 洋, 辻野 一三, 佐藤 隆博, 加藤 千恵次, 西村 正治, 玉木 長良
    核医学 (一社)日本核医学会 53 (Suppl.) S305 - S305 0022-7854 2016/10
  • 15O-H2O心筋血流PETにおける撮像時間短縮の検討:新アルゴリズムの考案
    林 蒼一朗, 富山 勇輝, 相川 忠夫, 真鍋 治, 納谷 昌直, 小原 雅彦, 孫田 惠一, 吉永 恵一郎, 丸尾 彩花, 加藤 千恵次, 玉木 長良
    核医学 (一社)日本核医学会 53 (Suppl.) S261 - S261 0022-7854 2016/10 [Refereed][Not invited]
  • 15O-H2O心筋血流PETにおける撮像時間短縮の検討:局所病変検出能の評価
    川内 敬介, 富山 勇輝, 相川 忠夫, 真鍋 治, 納谷 昌直, 小原 雅彦, 孫田 惠一, 吉永 恵一郎, 丸尾 彩花, 加藤 千恵次, 玉木 長良
    核医学 (一社)日本核医学会 53 (Suppl.) S261 - S261 0022-7854 2016/10 [Refereed][Not invited]
  • Noriki Ochi, Keiichiro Yoshinaga, Yoichi M Ito, Yuuki Tomiyama, Mamiko Inoue, Mutsumi Nishida, Osamu Manabe, Hitoshi Shibuya, Chikara Shimizu, Eriko Suzuki, Satoshi Fujii, Chietsugu Katoh, Nagara Tamaki
    Journal of cardiology 68 (4) 316 - 23 2016/10 [Refereed][Not invited]
     
    BACKGROUND: Comprehensive evaluation of endothelium-dependent and endothelium-independent vascular functions in peripheral arteries and coronary arteries in smokers has never been performed previously. Through the use of brachial artery ultrasound and oxygen-15-labeled water positron emission tomography (PET), we sought to investigate peripheral and coronary vascular dysfunctions in smokers. METHODS AND RESULTS: Eight smokers and 10 healthy individuals underwent brachial artery ultrasound at rest, during reactive hyperemia [250mmHg cuff occlusion (flow-mediated dilatation (FMD)], and following sublingual nitroglycerin (NTG) administration. Myocardial blood flow (MBF) was assessed through O-15-labeled water PET at rest, during adenosine triphosphate (ATP) administration, and during a cold pressor test (CPT). Through ultrasound, smokers were shown to have significantly reduced %FMD compared to controls (6.62±2.28% vs. 11.29±2.75%, p=0.0014). As assessed by O-15-labeled water PET, smokers were shown to have a significantly lower CPT response than were controls (21.1±9.5% vs. 50.9±16.9%, p=0.0004). There was no relationship between %FMD and CPT response (r=0.40, p=0.097). Endothelium-independent vascular dilatation was similar for both groups in terms of coronary flow reserve with PET (p=0.19). Smokers tended to have lower %NTG in the brachial artery (p=0.055). CONCLUSIONS: Smokers exhibited impaired coronary endothelial function as well as peripheral brachial artery endothelial function. In addition, there was no correlation between PET and ultrasound measurements, possibly implying that while smokers may have systemic vascular endothelial dysfunction, the characteristics of that dysfunction may be different in peripheral arteries and coronary arteries.
  • Yoshinaga Keiichiro, Tomiyama Yuuki, Hiroshi Ohira, Manabe Osamu, Tsujino Ichizo, Katoh Chietsugu, Masaharu Nishimura, Tamaki Nagara
    JOURNAL OF NUCLEAR MEDICINE 57 0161-5505 2016/05/01 [Refereed][Not invited]
  • Maruo Ayaka, Manabe Osamu, Yoshinaga Keiichiro, Naya Masanao, Tomiyama Yuuki, Oyama-Manabe Noriko, Hirata Kenji, Magota Keiichi, Tsutsui Hiroyuki, Katoh Chietsugu, Tamaki Nagara
    Annals of Nuclear Cardiology 日本心臓核医学会 2 (1) 30 - 37 2016 
    Purpose: The quantification of coronary flow reserve (CFR) calculated as the ratio of the myocardial blood flow (MBF) during adenosine triphosphate (ATP) stress to MBF at rest is a useful method for evaluating the functional severity of coronary artery disease (CAD) using 15O-H2O positron emission tomography (PET). The shorter acquisition time may reduce dyspnea and other side effects of ATP stress and may also reduce the effect of body movements during data acquisition. However, the impact of the shorter data acquisition time on the accuracy of MBF quantification has not been studied. In this retrospective study, we evaluated the accuracy of the MBF and CFR values obtained with shorter scan times using 15O-H2O PET.
    Methods: Thirty patients suspected of having CAD (22 males, 8 females; age 56.5±8.8 yrs) and 17 healthy controls (17 males; age 27.7±6.2 yrs) underwent PET during rest and PET with ATP stress dynamic 15O-H2O. The MBF was estimated with a one-tissue compartment model analysis. MBF and CFR values were calculated using the first 2-min and 3-min PET data of 15O-H2O as shorter data acquisitions. These data were compared to the standard 6-min PET acquisition data.
    Results: With the use of the 3-min data, the regions of interest (ROIs) in the left ventricular (LV) chamber and myocardium could be set for all of the subjects. The intraclass correlation coefficients (ICCs) between the 3-min data and 6-min data of the rest MBF, stress MBF and CFR were 0.869, 0.870, and 0.819 in the patients, and 0.912, 0.910, and 0.930 in the controls. The 3-min CFR data showed a significant difference between the patients and controls (2.22±1.02 vs. 4.02±1.50, p<0.01), as did the 6-min data (2.19±0.92 vs. 4.16±1.39, p<0.01). However, the CFR based on 2-min data did not show a significant difference (1.96±1.66 vs. 2.73±1.03, p=0.088). Using a receiver operating characteristic (ROC) analysis, we observed that both the 3-min and 6-min CFR data could be used to separate the CAD patients and controls.
    Conclusions: A 3-min, but not 2-min, scan with 15O-H2O PET can be used for the quantitative evaluation of MBF and CFR.
  • 慢性血栓性肺高血圧症における両側肺血流量の低下 酸素15標識水ポジトロン断層撮像による定量的検出
    吉永 恵一郎, 富山 勇輝, 大平 洋, 辻野 一三, 佐藤 隆博, 真鍋 治, 加藤 千恵次, 西村 正治, 玉木 長良
    核医学 (一社)日本核医学会 52 (3) 257 - 257 0022-7854 2015/09
  • Yuuki Tomiyama, Osamu Manabe, Noriko Oyama-Manabe, Masanao Naya, Hiroyuki Sugimori, Kenji Hirata, Yuki Mori, Hiroyuki Tsutsui, Kohsuke Kudo, Nagara Tamaki, Chietsugu Katoh
    Journal of magnetic resonance imaging : JMRI 42 (3) 754 - 62 2015/09 [Refereed][Not invited]
     
    BACKGROUND: To develop and validate a method for quantifying myocardial blood flow (MBF) using dynamic perfusion magnetic resonance imaging (MBFMRI ) at 3.0 Tesla (T) and compare the findings with those of (15) O-water positron emission tomography (MBFPET ). METHODS: Twenty healthy male volunteers underwent magnetic resonance imaging (MRI) and (15) O-water positron emission tomography (PET) at rest and during adenosine triphosphate infusion. The single-tissue compartment model was used to estimate the inflow rate constant (K1). We estimated the extraction fraction of Gd-DTPA using K1 and MBF values obtained from (15) O-water PET for the first 10 subjects. For validation, we calculated MBFMRI values for the remaining 10 subjects and compared them with the MBFPET values. In addition, we compared MBFMRI values of 10 patients with coronary artery disease with those of healthy subjects. RESULTS: The mean resting and stress MBFMRI values were 0.76 ± 0.10 and 3.04 ± 0.82 mL/min/g, respectively, and showed excellent correlation with the mean MBFPET values (r = 0.96, P < 0.01). The mean stress MBFMRI value was significantly lower for the patients (1.92 ± 0.37) than for the healthy subjects (P < 0.001). CONCLUSION: The use of dynamic perfusion MRI at 3T is useful for estimating MBF and can be applied for patients with coronary artery disease.
  • Yuuki Tomiyama, Keiichiro Yoshinaga, Satoshi Fujii, Noriki Ochi, Mamiko Inoue, Mutumi Nishida, Kumi Aziki, Tatsunori Horie, Chietsugu Katoh, Nagara Tamaki
    HYPERTENSION RESEARCH 38 (7) 478 - 484 0916-9636 2015/07 [Refereed][Not invited]
     
    Increasing vascular diameter and attenuated vascular elasticity may be reliable markers for atherosclerotic risk assessment. However, previous measurements have been complex, operator-dependent or invasive. Recently, we developed a new automated oscillometric method to measure a brachial artery's estimated area (eA) and volume elastic modulus (V-E). The aim of this study was to investigate the reliability of new automated oscillometric measurement of eA and V-E. Rest eA and V-E were measured using the recently developed automated detector with the oscillometric method. eA was estimated using pressure/volume curves and V-E was defined as follows (V-E = Delta pressure/(100 x Delta area/area) mmHg/%). Sixteen volunteers (age 35.2 +/- 13.1 years) underwent the oscillometric measurements and brachial ultrasound at rest and under nitroglycerin (NTG) administration. Oscillometric measurement was performed twice on different days. The rest eA correlated with ultrasound-measured brachial artery area (r=0.77, P<0.001). Rest eA and V-E measurement showed good reproducibility (eA: intraclass correlation coefficient (ICC)=0.88, V-E: ICC=0.78). Under NTG stress, eA was significantly increased (12.3 +/- 3.0 vs. 17.1 +/- 4.6mm(2), P<0.001), and this was similar to the case with ultrasound evaluation (4.46 +/- 0.72 vs. 4.73 +/- 0.75 mm, P<0.001). V-E was also decreased (0.81 +/- 0.16 vs. 0.65 +/- 0.11mmHg/%, P<0.001) after NTG. Cross-sectional vascular area calculated using this automated oscillometric measurement correlated with ultrasound measurement and showed good reproducibility. Therefore, this is a reliable approach and this modality may have practical application to automatically assess muscular artery diameter and elasticity in clinical or epidemiological settings.
  • Keiichiro Yoshinaga, Yuuki Tomiyama, Ichizo Tsujino, Hiroshi Ohira, Osamu Manabe, Chietsugu Katoh, Masaharu Nishimura, Nagara Tamaki
    JOURNAL OF NUCLEAR MEDICINE 56 (3) 0161-5505 2015/05 [Refereed][Not invited]
  • 3T心臓パーフュージョンMRIを用いた心筋血流定量法の確立(How to quantify cardiac perfusion MRI at 3 tesla in comparison with water PET)
    Manabe Noriko, Tomiyama Yuuki, Manabe Osamu, Katoh Chietsugu, Sugimori Hiroyuki, Kikuchi Yasuka, Kato Fumi, Kudo Kohsuke, Miyamoto Noriyuki, Nagara Tamaki
    日本医学放射線学会学術集会抄録集 74回 S289 - S289 0048-0428 2015/02
  • KATOH CHIETSUGU
    Transactions of Japanese Society for Medical and Biological Engineering 一般社団法人 日本生体医工学会 53 S212_02 - S212_02 2015 
    Objective: Using 15O-H2O PET data, we developed a protocol to estimate myocardial blood flow (MBF) from dynamic multi-detector CT with low dose radiation exposure. Method: Twenty-two subjects underwent both dynamic CT and PET at rest and during stress. In 12 normal subjects (pilot group), the calculation for MBF with single compartment model was established. In the other 10 normal subjects (validation group), MBF estimated by CT and PET were compared. CT data were acquired at every heart beat for 20 seconds with ECG gated scan. Radiation exposure for each CT study was 9mSv to acquire 30 beats data. To develop a low exposure protocol, MBF were recalculated using skipped CT data for 1,2,3 and 4 beats interval. Result: In the pilot group, significant correlation was yielded between MBF from no-skipped CT data and PET (r=0.950, P<0.01). In the validation group, correlation between MBF from no-skipped CT and skipped CT for 1,2,3 and 4 beats interval were 0.995, 0.990, 0.983 and 0.953. MBF from 4 beats interval CT yielded low coefficient (P<0.01), at least 3 beats interval data is needed to estimate MBF by ECG gated CT. It reduces exposure to quarter compared with no-skipped CT.
  • 西村正治, 吉永恵一郎, 大平洋, 辻野一三, 真鍋徳子, MIELNICZUK L, BEANLANDS R S B, 加藤千恵次, 葛西克彦, 真鍋治, 佐藤隆博, 藤井聡, 伊藤陽一, 富山勇輝, 玉木長良
    呼吸不全に関する調査研究 平成26年度 総括・分担研究報告書 257‐259  2015 [Not refereed][Not invited]
  • Yuki Mori, Osamu Manabe, Masanao Naya, Yuuki Tomiyama, Keiichiro Yoshinaga, Keiichi Magota, Noriko Oyama-Manabe, Kenji Hirata, Hiroyuki Tsutsui, Nagara Tamaki, Chietsugu Katoh
    Annals of nuclear medicine 29 (1) 15 - 20 2015/01 [Refereed][Not invited]
     
    OBJECTIVE: (11)C-acetate has been applied for evaluation of myocardial oxidative metabolism and can simultaneously estimate myocardial blood flow (MBF). We developed a new method using two-parameter spillover correction to estimate regional MBF (rMBF) with (11)C-acetate PET in reference to MBF derived from (15)O-H2O PET. The usefulness of our new approach was evaluated compared to the conventional method using one-parameter spillover correction. METHODS: Sixty-three subjects were examined with (11)C-acetate and (15)O-H2O dynamic PET at rest. Inflow rate of (11)C-acetate (K1) was compared with MBF derived from (15)O-H2O PET. For the derivation, the relationship between K1 and MBF from (15)O-H2O was linked by the Renkin-Crone model in 20 subjects as a pilot group. One-parameter and two-parameter corrections were applied to suppress the spillover between left ventricular (LV) wall and LV cavity. Validation was set using the other 43 subjects' data. Finally, rMBFs were calculated using relational expression derived from the pilot-group data. RESULTS: The relationship between K1 and MBF derived from (15)O-H2O PET was approximated as K1 = [1-0.764 × exp(-1.001/MBF)] MBF from the pilot data using the two-parameter method. In the validation set, the correlation coefficient between rMBF from (11)C-acetate and (15)O-H2O demonstrated a significantly higher relationship with the two-parameter spillover correction method than the one-parameter spillover correction method (r = 0.730, 0.592, respectively, p < 0.05). CONCLUSION: In (11)C-acetate PET study, the new two-parameter spillover correction method dedicated more accurate and robust myocardial blood flow than the conventional one-parameter method.
  • Sergey V. Nesterov, Emmanuel Deshayes, Roberto Sciagra, Leonardo Settimo, Jerome M. Declerck, Xiao-Bo Pan, Keiichiro Yoshinaga, Chietsugu Katoh, Piotr J. Slomka, Guido Germano, Chunlei Han, Ville Aalto, Adam M. Alessio, Edward P. Ficaro, Benjamin C. Lee, Stephan G. Nekolla, Kilem L. Gwet, Robert A. deKemp, Ran Klein, John Dickson, James A. Case, Timothy Bateman, John O. Prior, Juhani M. Knuuti
    JACC-CARDIOVASCULAR IMAGING 7 (11) 1119 - 1127 1936-878X 2014/11 [Refereed][Not invited]
     
    OBJECTIVES The purpose of this study was to compare myocardial blood flow (MBF) and myocardial flow reserve (MFR) estimates from rubidium-82 positron emission tomography (Rb-82 PET) data using 10 software packages (SPs) based on 8 tracer kinetic models. BACKGROUND It is unknown how MBF and MFR values from existing SPs agree for Rb-82 PET. METHODS Rest and stress Rb-82 PET scans of 48 patients with suspected or known coronary artery disease were analyzed in 10 centers. Each center used 1 of 10 SPs to analyze global and regional MBF using the different kinetic models implemented. Values were considered to agree if they simultaneously had an intraclass correlation coefficient >0.75 and a difference <20% of the median across all programs. RESULTS The most common model evaluated was the Ottawa Heart Institute 1-tissue compartment model (OHI-1-TCM). MBF values from 7 of 8 SPs implementing this model agreed best. Values from 2 other models (alternative 1-TCM and Axially distributed) also agreed well, with occasional differences. The MBF results from other models (e.g., 2-TCM and retention) were less in agreement with values from OHI-1-TCM. CONCLUSIONS SPs using the most common kinetic model-OHI-1-TCM-provided consistent results in measuring global and regional MBF values, suggesting that they may be used interchangeably to process data acquired with a common imaging protocol. (C) 2014 by the American College of Cardiology Foundation.
  • Keiichiro Yoshinaga, Yuuki Tomiyama, Osamu Manabe, Katsuhiko Kasai, Chietsugu Katoh, Kenichi Magota, Eriko Suzuki, Ken-Ichi Nishijima, Yuji Kuge, Yoichi M Ito, Nagara Tamaki
    Annals of nuclear medicine 28 (8) 761 - 9 2014/10 [Refereed][Not invited]
     
    OBJECTIVES: (123)I-metaiodobenzylguanidine (MIBG) has been used to estimate cardiac sympathetic nervous innervation. Heterogeneous MIBG distribution is mainly associated with high physiological MIBG uptakes in the liver. We postulate that prone position acquisition might be especially effective for MIBG, providing for separation from high liver uptake similar to that provided by perfusion single-photon emission computed tomography (SPECT). We investigated whether prone-position acquisition improved MIBG image quality by comparing our results to those acquired using supine MIBG and high-quality (11)C-hydroxyephedrine (HED) positron emission tomography/computed tomography PET/CT. METHODS: Ten male volunteers (body mass index (BMI) 22.7 ± 3.4) underwent prone and supine MIBG and HED PET. Relative regional tracer uptake was estimated in early MIBG and HED. Acquired images were divided into 17 segments and were grouped into 4 regions: anterior, inferior, septum, and lateral. For each patient, the inferior/anterior ratio was calculated. RESULTS: The quality of images acquired using prone MIBG was better than that using supine MIBG (p < 0.05). Inferior and septum relative MIBG uptake was reduced in comparison with anterior or lateral MIBG uptake in the supine position (inferior vs. anterior: 69.0 ± 5.6 vs. 82.3 ± 4.6 %, p < 0.01; septum vs. lateral: 66.2 ± 5.1 vs. 81.9 ± 5.4 %, p < 0.01). Prone MIBG showed a significantly higher inferior/anterior uptake ratio in comparison with supine MIBG (n = 24, seg: 92.2 ± 7.2 vs. 83.6 ± 5.7 %, p < 0.05). However, intergroup differences in uptake ratio were demonstrated among prone and supine MIBG and HED. HED PET/CT still showed a higher uptake ratio in comparison with prone MIBG SPECT (103.9 ± 8.0 vs. 92.2 ± 7.2 %, p < 0.05). CONCLUSION: Even in normal male subjects, standard supine MIBG imaging showed reduced inferior and septum uptake. Uptake with prone MIBG imaging showed a significant improvement over that with supine imaging and was closer to uptake for HED PET/CT. This improvement may be the result of preventing intense uptake by the liver. Prone data acquisition may be a viable alternative in evaluating regional abnormalities using MIBG SPECT in men.
  • 慢性腎臓病患者における上腕動脈容積弾性率低下は血管内皮機能障害と関連するが上腕-足首間脈波伝播速度(baPWV)とは関連しない
    吉永 恵一郎, 富山 勇輝, 西尾 沙織, 松岡 奈央子, 越智 典樹, 加藤 千恵次, 井上 真美子, 西田 睦, 伊藤 陽一, 西林 秀郎, 藤井 聡, 玉木 長良
    日本心臓病学会学術集会抄録 (一社)日本心臓病学会 62回 P - 543 2014/09
  • 酸素15標識水ポジトロン断層撮像による慢性血栓性肺高血圧症における肺血流量の低下の定量的検出
    吉永 恵一郎, 富山 勇輝, 辻野 一三, 佐藤 隆博, 真鍋 治, 加藤 千恵次, 大平 洋, 西村 正治, 玉木 長良
    核医学 (一社)日本核医学会 51 (3) 332 - 332 0022-7854 2014/09
  • Yasuka Kikuchi, Noriko Oyama-Manabe, Masanao Naya, Osamu Manabe, Yuuki Tomiyama, Tsukasa Sasaki, Chietsugu Katoh, Kohsuke Kudo, Nagara Tamaki, Hiroki Shirato
    European radiology 24 (7) 1547 - 56 2014/07 [Refereed][Not invited]
     
    OBJECTIVES: This study introduces a method to calculate myocardium blood flow (MBF) and coronary flow reserve (CFR) using the relatively low-dose dynamic 320-row multi-detector computed tomography (MDCT), validates the method against (15)O-H₂O positron-emission tomography (PET) and assesses the CFRs of coronary artery disease (CAD) patients. METHODS: Thirty-two subjects underwent both dynamic CT perfusion (CTP) and PET perfusion imaging at rest and during pharmacological stress. In 12 normal subjects (pilot group), the calculation method for MBF and CFR was established. In the other 13 normal subjects (validation group), MBF and CFR obtained by dynamic CTP and PET were compared. Finally, the CFRs obtained by dynamic CTP and PET were compared between the validation group and CAD patients (n = 7). RESULTS: Correlation between MBF of MDCT and PET was strong (r = 0.95, P < 0.0001). CFR showed good correlation between dynamic CTP and PET (r = 0.67, P = 0.0126). CFRCT in the CAD group (2.3 ± 0.8) was significantly lower than that in the validation group (5.2 ± 1.8) (P = 0.0011). CONCLUSIONS: We established a method for measuring MBF and CFR with the relatively low-dose dynamic MDCT. Lower CFR was well demonstrated in CAD patients by dynamic CTP. KEY POINTS: • MBF and CFR can be calculated using dynamic CTP with 320-row MDCT. • MBF and CFR showed good correlation between dynamic CTP and PET. • Lower CFR was well demonstrated in CAD patients by dynamic CTP.
  • Keiichiro Yoshinaga, Hiroshi Ohira, Ichizo Tsujino, Noriko Oyama-Manabe, Lisa Mielniczuk, Rob S B Beanlands, Chietsugu Katoh, Katsuhiko Kasai, Osamu Manabe, Takahiro Sato, Satoshi Fujii, Yoichi M Ito, Yuuki Tomiyama, Masaharu Nishimura, Nagara Tamaki
    European journal of nuclear medicine and molecular imaging 41 (6) 1240 - 50 2014/06 [Refereed][Not invited]
     
    PURPOSE: The right ventricle (RV) has a high capacity to adapt to pressure or volume overload before failing. However, the mechanisms of RV adaptation, in particular RV energetics, in patients with pulmonary hypertension (PH) are still not well understood. We aimed to evaluate RV energetics including RV oxidative metabolism, power and efficiency to adapt to increasing pressure overload in patients with PH using (11)C-acetate PET. METHODS: In this prospective study, 27 patients with WHO functional class II/III PH (mean pulmonary arterial pressure 39.8 ± 13.5 mmHg) and 9 healthy individuals underwent (11)C-acetate PET. (11)C-acetate PET was used to simultaneously measure oxidative metabolism (k mono) for the left ventricle (LV) and RV. LV and RV efficiency were also calculated. RESULTS: The RV ejection fraction in PH patients was lower than in controls (p = 0.0054). There was no statistically significant difference in LV k mono (p = 0.09). In contrast, PH patients showed higher RV k mono than did controls (0.050 ± 0.009 min(-1) vs. 0.030 ± 0.006 min(-1), p < 0.0001). PH patients exhibited significantly increased RV power (p < 0.001) and hence increased RV efficiency compared to controls (0.40 ± 0.14 vs. 0.017 ± 0.12 mmHg·mL·min/g, p = 0.001). CONCLUSION: The RV oxidative metabolic rate was increased in patients with PH. Patients with WHO functional class II/III PH also had increased RV power and efficiency. These findings may indicate a myocardial energetics adaptation response to increasing pulmonary arterial pressure.
  • Keiichiro Yoshinaga, Yuuki Tomiyama, Ichizo Tsujino, Takahiro Sato, Osamu Manabe, Chietsugu Katoh, Hiroshi Ohira, Masaharu Nishimura, Nagara Tamaki
    JOURNAL OF NUCLEAR MEDICINE 55 0161-5505 2014/05 [Refereed][Not invited]
  • Keiichiro Yoshinaga, Hiroshi Ohira, Ichizo Tsujino, Chietsugu Katoh, Katsuhiko Kasai, Yuuki Tomiyama, Takahiro Sato, Noriko Oyama-Manabe, Masaharu Nishimura, Nagara Tamaki
    JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 63 (12) A1018 - A1018 0735-1097 2014/04 [Refereed][Not invited]
  • 15O-水PETを用いて検証したダイナミック灌流3テスラMRIによる心筋血流量の定量 領域分析への応用(Quantification of myocardial blood flow with dynamic perfusion 3.0 Tesla MRI using validation with 15O-water PET: Application to regional analysis)
    Tomiyama Yuuki, Manabe Osamu, Oyama-Manabe Noriko, Kikuchi Yasuka, Sugimori Hiroyuki, Katoh Chietsugu, Tamaki Nagara
    日本放射線技術学会総会学術大会予稿集 70回 134 - 135 1884-7846 2014/02
  • Keiichiro Yoshinaga, Hiroshi Ohira, Ichizo Tsujino, Osamu Manabe, Takahiro Sato, Chietsugu Katoh, Katsuhiko Kasai, Yuuki Tomiyama, Noriko Oyama-Manabe, Masaharu Nishimura, Nagara Tamaki
    JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 61 (10) E1002 - E1002 0735-1097 2013/03 [Refereed][Not invited]
  • Satoru Chiba, Masanao Naya, Hiroyuki Iwano, Keiichiro Yoshinaga, Chietsugu Katoh, Osamu Manabe, Satoshi Yamada, Satoru Wakasa, Suguru Kubota, Yoshiro Matsui, Nagara Tamaki, Hiroyuki Tsutsui
    European journal of nuclear medicine and molecular imaging 40 (3) 349 - 55 2013/02 [Refereed][Not invited]
     
    PURPOSE: Diastolic function is impaired in patients with end-stage heart failure. Favorable structural changes by surgical ventricular reconstruction (SVR) are thought to improve diastolic function, however, previous studies reported the contradictory results. We hypothesized that cardiac oxidative metabolism and diastolic dysfunction might improve in parallel to the reduction of left ventricular chamber size after SVR. METHODS: We studied 11 patients underwent SVR associated with mitral valve repair for end-stage heart failure due to dilated cardiomyopathy. Diastolic function was assessed by echocardiography and myocardial oxidative metabolism was measured by the monoexponential clearance (k-mono) of (11)C-acetate positron emission tomography at baseline and 1 month after SVR. RESULTS: All patients had preoperative severe diastolic dysfunction [E/A 4.11 ± 1.18, deceleration time (DT) 134 ± 26 ms]. The study patients were divided into 2 groups according to the changes in diastolic function after SVR; unchanged or worsened diastolic function in 6 patients (55 %, Non-responder) and improved diastolic function in 5 (45 %, Responder). K-mono and wall stress decreased only in responder. The changes in k-mono before and after SVR correlated with those in deceleration time (r =  -0.63; p < 0.05) and wall stress (r = 0.75; p < 0.01). CONCLUSIONS: Improvement of diastolic dysfunction in patients with end-stage heart failure by SVR was in parallel to that in oxidative metabolism. It suggests that SVR reduced excessive metabolism during the diastolic phase, in part, via the improvement in diastolic function and the reduction in LV wall stress.
  • Chietsugu Katoh, Keiichiro Yoshinaga, Ran Klein, Katsuhiko Kasai, Yuuki Tomiyama, Osamu Manabe, Masanao Naya, Mamoru Sakakibara, Hiroyuki Tsutsui, Robert A deKemp, Nagara Tamaki
    Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology 19 (4) 763 - 74 2012/08 [Refereed][Not invited]
     
    PURPOSE: Myocardial blood flow (MBF) estimation with (82)Rubidium ((82)Rb) positron emission tomography (PET) is technically difficult because of the high spillover between regions of interest, especially due to the long positron range. We sought to develop a new algorithm to reduce the spillover in image-derived blood activity curves, using non-uniform weighted least-squares fitting. METHODS: Fourteen volunteers underwent imaging with both 3-dimensional (3D) (82)Rb and (15)O-water PET at rest and during pharmacological stress. Whole left ventricular (LV) (82)Rb MBF was estimated using a one-compartment model, including a myocardium-to-blood spillover correction to estimate the corresponding blood input function Ca(t)(whole). Regional K1 values were calculated using this uniform global input function, which simplifies equations and enables robust estimation of MBF. To assess the robustness of the modified algorithm, inter-operator repeatability of 3D (82)Rb MBF was compared with a previously established method. RESULTS: Whole LV correlation of (82)Rb MBF with (15)O-water MBF was better (P < .01) with the modified spillover correction method (r = 0.92 vs r = 0.60). The modified method also yielded significantly improved inter-operator repeatability of regional MBF quantification (r = 0.89) versus the established method (r = 0.82) (P < .01). CONCLUSION: A uniform global input function can suppress LV spillover into the image-derived blood input function, resulting in improved precision for MBF quantification with 3D (82)Rb PET.
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  • Keiichiro Yoshinaga, Hiroshi Ohira, Ichizo Tsujino, Osamu Manabe, Chietsugu Katoh, Katsuhiko Kasai, Takahiro Satoh, Noriko Oyama-Manabe, Masaharu Nishimura, Nagara Tamaki
    CIRCULATION 124 (21) 0009-7322 2011/11 [Refereed][Not invited]
  • 西嶋剣一, 吉永恵一郎, 趙松吉, 趙芫, 真鍋治, 加藤千恵次, 阿保憲史, 玉木長良, 久下裕司, 久下裕司
    核医学 (一社)日本核医学会 48 (3) S256 - S256 0022-7854 2011/09 [Not refereed][Not invited]
  • Keiichiro Yoshinaga, Hiroshi Ohira, Ichizo Tsujino, Osamu Manabe, Chietsugu Katoh, Katsuhiko Kasai, Takahiro Satoh, Noriko Oyama, Masaharu Nishimura, Nagara Tamaki
    JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 57 (14) E845 - E845 0735-1097 2011/04 [Refereed][Not invited]
  • Masanao Naya, Koichi Morita, Keiichiro Yoshinaga, Osamu Manabe, Daisuke Goto, Kenji Hirata, Chietsugu Katoh, Nagara Tamaki, Hiroyuki Tsutsui
    European journal of nuclear medicine and molecular imaging 38 (3) 491 - 8 1619-7070 2011/03 [Refereed][Not invited]
     
    PURPOSE: Smoking cessation has been shown to normalize the coronary endothelial dysfunction in healthy young smokers. However, its effect has not been explored in middle-aged smokers with a longer history of smoking. Therefore, we compared the effects of smoking cessation on coronary vasomotor response between both young and middle-aged smokers and identified the predictor for its improvement. METHODS: This study investigated 14 young healthy smokers (age 25.2 ± 2.3 years), 13 middle-aged smokers (age 42.0 ± 6.5 years) and 10 non-smokers. Myocardial blood flow (MBF) was measured by using (15)O-water positron emission tomography (PET). RESULTS: At baseline, the ratio of MBF during the cold pressor test (CPT) to that at rest (MBF(CPT/rest)), the index of coronary endothelial function, was significantly decreased in both young and middle-aged smokers compared to non-smokers (1.24 ± 0.20 and 1.10 ± 0.39 vs 1.53 ± 0.18, p < 0.05 and p < 0.001, respectively). The ratio of MBF during adenosine triphosphate infusion to that at rest was significantly decreased in middle-aged smokers compared to young smokers and non-smokers (3.34 ± 1.52 vs 4.43 ± 0.92 and 4.69 ± 1.25, p < 0.05, respectively). MBF(CPT/rest) at 1 month after smoking cessation significantly increased in young smokers, but not in middle-aged smokers. By multivariate analysis, baseline serum malondialdehyde-modified low-density lipoprotein (MDA-LDL) was an independent predictor for the changes in MBF(CPT/rest) after smoking cessation (β = -0.45, p < 0.05). CONCLUSION: Coronary endothelial dysfunction was reversible by short-term smoking cessation in young smokers, but not in middle-aged smokers, which was associated with serum MDA-LDL levels. Long-term smoking exposure could lead to more advanced coronary endothelial dysfunction and atherosclerosis possibly via oxidative stress.
  • Keiichiro Yoshinaga, Chietsugu Katoh, Osamu Manabe, Ran Klein, Masanao Naya, Mamoru Sakakibara, Shiro Yamada, Robert A Dekemp, Hiroyuki Tsutsui, Nagara Tamaki
    Circulation journal : official journal of the Japanese Circulation Society 75 (11) 2628 - 34 1346-9843 2011 [Refereed][Not invited]
     
    BACKGROUND: Myocardial blood flow (MBF) can be measured with positron emission tomography (PET) and its quantification should provide diagnostic information beyond that obtained through standard visual analysis. However, this possibility has not been fully studied with PET and generator-produced rubidium-82 (⁸²Rb). We evaluated regional MBF in segments with and without ischemia using ⁸²Rb PET in patients with coronary artery disease (CAD). METHODS AND RESULTS: Rest and stress ⁸²Rb PET and coronary angiography were performed for 12 patients with CAD. Based on angiography and relative ⁸²Rb perfusion images, segments were classified into 4 groups (Group A: myocardial ischemia with >70% diameter stenosis; Group B: no ischemia with stenosis; Group C: no ischemia without stenosis; Group D: ischemia without stenosis). Rest MBF was similar among the 4 groups. Groups A and B showed reduced hyperemic MBF compared with Group C (P < 0.05 vs. Group C) [Group A (n=16) 1.28 ± 0.58 ml·min⁻¹·g⁻¹; Group B (n=11) 1.72 ± 0.64 ml·min⁻¹·g⁻¹; Group C (n=9) 2.60 ± 1.09 ml·min⁻¹·g⁻¹; Group D (n=2) 2.33 ml·min⁻¹·g⁻¹]. Coronary flow reserves were inversely correlated with percent diameter stenosis (r=0.76, P < 0.0001). CONCLUSIONS: Segments with ischemia and coronary stenosis had reduced hyperemic MBF. Segments with coronary stenosis without ischemia also had reduced hyperemic MBF compared with non-stenotic segments. MBF quantification using ⁸²Rb PET may provide additional diagnostic information.
  • 小動物用PETを用いた11C‐FlumazenilのBinding potential解析におけるMaximum a posteriori再構成の評価
    孫田惠一, 久保直樹, 趙松吉, 久下裕司, 平田健司, 服部直也, 志賀哲, 加藤千恵次, 玉木長良
    核医学 48 (3) 329  2011 [Not refereed][Not invited]
  • 小動物用PETを用いた[11C]Flumazenilのコンパートメントモデル解析におけるMaximum a posteriori(MAP)再構成の評価
    孫田惠一, 久保直樹, 趙松吉, 久下裕司, 玉木長良, 加藤千恵次
    北海道放射線技術雑誌 71 127  2011 [Not refereed][Not invited]
  • Kenji Hirata, Naoya Hattori, Chietsugu Katoh, Tohru Shiga, Satoshi Kuroda, Naoki Kubo, Reiko Usui, Yuji Kuge, Nagara Tamaki
    NUCLEAR MEDICINE COMMUNICATIONS 32 (1) 63 - 70 0143-3636 2011/01 [Refereed][Not invited]
     
    Objective Cerebral blood flow (CBF) estimation with C(15)O(2) PET usually assumes a single tissue compartment model and a fixed brain-blood partition coefficient of water. However, the partition coefficient may change in pathological conditions. The purpose of this study was to investigate the changes in the partition coefficient of water in pathological regions and its effect on regional CBF assessment. Methods The study protocol included 22 patients with occlusive cerebrovascular disease to compare the partition coefficients among three regions (infarction area, noninfarct hypoperfusion area, and contralateral area) in the pathological brain (analysis A), and to compare the CBF estimated by using a fixed partition coefficient and CBF estimated using floating partition coefficients (analysis B). Results The partition coefficient in the infarction area (0.55 +/- 0.07 ml/g) was lower than that in the contralateral normal cortex (0.68 +/- 0.05 ml/g), whereas noninfarct hypoperfusion area did not show a significant change (0.67 +/- 0.06 ml/g). As a result, the use of a fixed partition coefficient of normal volunteers (0.70 ml/g) resulted in an underestimation in regional CBF by 12% in infarction area (P<0.05), whereas the estimation errors were smaller and induced no significant difference in the noninfarct hypoperfusion area or in contralateral areas. Conclusion The partition coefficient is stable except for the infarction area, and CBF estimation using a fixed partition coefficient of normal volunteers provides clinically appreciable information in patients with cerebrovascular disease. Nucl Med Commun 32:63-70 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
  • Masanao Naya, Satoru Chiba, Hiroyuki Iwano, Satoshi Yamada, Chietsugu Katoh, Osamu Manabe, Keiichiro Yoshinaga, Yoshiro Matsui, Nagara Tamaki, Hiroyuki Tsutsui
    European journal of nuclear medicine and molecular imaging 37 (12) 2242 - 8 1619-7070 2010/12 [Refereed][Not invited]
     
    PURPOSE: The relationship between myocardial oxidative metabolism and pressure overload in aortic valve stenosis (AS) is not fully elucidated. We identified the determinants of myocardial oxidative metabolism by measuring its changes after aortic valve replacement (AVR) in patients with AS. METHODS: Myocardial 11C-acetate clearance rate constant (Kmono), an index of oxidative metabolism, was measured non-invasively by using positron emission tomography in 16 patients with moderate to severe AS and 7 healthy controls. The severity of AS was assessed by echocardiography. Of 16 patients, 5 were reexamined at 1 month after AVR. RESULTS: Kmono was significantly higher in patients with AS than healthy controls by 42% (0.068±0.014 vs 0.048±0.007/min, p<0.01). Kmono was significantly correlated with age (r=0.58, p<0.01), left ventricular (LV) mass index (r=0.61, p<0.01) and estimated systolic LV pressure (r=0.81, p<0.001) measured by echocardiography. By multivariate analysis, estimated LV systolic pressure was an independent predictor of Kmono (β=0.93, p<0.01). After AVR, Kmono (from 0.075±0.012 to 0.061±0.014/min, p=0.043) and LV mass index (from 183±49 to 124±41 g/ml2, p=0.043) were significantly decreased despite no significant changes in rate-pressure product. CONCLUSION: Myocardial oxygen metabolism was increased in patients with AS, which was decreased after AVR. The increased myocardial oxidative metabolism in AS was largely attributable to the pressure overload of the LV.
  • Keiichiro Yoshinaga, Osamu Manabe, Chietsugu Katoh, Li Chen, Ran Klein, Masanao Naya, Robert A deKemp, Kathryn Williams, Rob S B Beanlands, Nagara Tamaki
    European journal of nuclear medicine and molecular imaging 37 (12) 2233 - 41 1619-7070 2010/12 [Refereed][Not invited]
     
    PURPOSE: Endothelial dysfunction is the earliest abnormality in the development of coronary atherosclerosis. 82Rb is a generator-produced positron emission tomography (PET) myocardial perfusion tracer that is becoming more widely used. We aimed to (1) develop a method for quantitative assessment of coronary endothelial function using the myocardial blood flow (MBF) response during a cold pressor test (CPT) in smokers, measured using 82Rb PET, and (2) compare the results with those measured using 15O-water PET. METHODS: MBF was assessed at rest and during the CPT with 82Rb and 15O-water in nine controls and ten smokers. A one-compartment model with tracer extraction correction was used to estimate MBF with both tracers. CPT response was calculated as the ratio of MBF during the CPT to MBF at rest. RESULTS: At rest, measurements of MBF for smokers vs controls were not different using 15O-water (0.86±0.18 vs 0.70±0.13, p=0.426) than they were using 82Rb (0.83±0.23 vs 0.62±0.20, p=0.051). Both methods showed a reduced CPT response in smokers vs controls (15O-water, 1.03±0.21 vs 1.42±0.29, p=0.006; 82Rb, 1.02±0.28 vs 1.70±0.52, p<0.001). There was high reliability [intraclass correlation coefficients: 0.48 (0.07, 0.75)] of MBF measurement between 82Rb and 15O-water during the CPT. CONCLUSION: Using a CPT, 82Rb MBF measurements detected coronary endothelial dysfunctions in smokers. 82Rb MBF measurements were comparable to those made using the 15O-water approach. Thus, 82Rb PET may be applicable for risk assessments or evaluation of risk factor modification in subjects with coronary risk factors.
  • Kobashi Keiji, Takeuchi Wataru, Morimoto Yuichi, Ishitsu Takafumi, Ueno Yuichiro, Matsuzaki Kazuki, Kubo Naoki, Katoh Chietsugu, Shiga Tohru, Tamaki Nagara
    JOURNAL OF NUCLEAR MEDICINE 51 0161-5505 2010/05 [Refereed][Not invited]
  • Tomohiro Osanai, Hirofumi Tomita, Masahiro Yamada, Makoto Tanaka, Toshihiro Ashitate, Takashi Echizen, Chisato Katoh, Koji Magota, Ken Okumura
    JOURNAL OF HYPERTENSION 27 (9) 1823 - 1828 0263-6352 2009/09 [Refereed][Not invited]
     
    Objectives Coupling factor 6 (CF6) attenuates the endothelial generation of prostacyclin. However, the role of CF6 in the resistance arteriole that is directly related to vascular tone is not determined yet. We investigated the effect of endogenous and exogenous CF6 on prostacyclin generation in cultured vascular smooth muscle cells (VSMCs). Methods and results We cultured resistance arteriole VSMCs from the mesenteric artery network of spontaneously hypertensive rats (SHRs, n=8) and Wistar-Kyoto rats (WKY, n=8) by enzymatic method. The gene expression of CF6 was higher by 76 +/- 24% in SHR-derived VSMCs compared with WKY rat-derived VSMCs (P<0.05) concomitant with the reduced degradation rate of CF6 mRNA. The release of CF6 in SHRs was higher than that in WKY rats (11.0 +/- 0.8 vs. 3.8 +/- 0.4 pg/mu g protein, P<0.05). Prostacyclin generation was attenuated in mesenteric arteriolar VSMCs from SHRs compared with those from WKY rats, but it was restored by neutralization of CF6 with its antibody. Exogenous administration of CF6 suppressed arachidonic acid release in a dose-dependent manner, and it was greater in SHRs than in WKY rats. Pretreatment with PP1, an inhibitor of tyrosine kinase c-Src, or receptor blockers such as ADP, efrapeptin, and an antibody to beta-subunit of ATP synthase blocked CF6-induced decrease in prostacyclin generation. Conclusion These data suggest that CF6 suppresses prostacyclin generation in resistance arteriole VSMCs in an autocrine or paracrine fashion, and it is enhanced in SHRs by the overproduction of CF6 and the hyperresponsiveness to CF6. J Hypertens 27:1823-1828 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
  • Tomohiro Osanai, Hirofumi Tomita, Motoi Kushibiki, Masahiro Yamada, Makoto Tanaka, Toshihiro Ashitate, Takashi Echizen, Chisato Katoh, Koji Magota, Ken Okumura
    CARDIOVASCULAR RESEARCH 81 (4) 780 - 787 0008-6363 2009/03 [Refereed][Not invited]
     
    Coupling factor 6 (CF6) induces hypertension by attenuating the endothelial generation of prostacyclin. However, intracellular signalling of CF6 in the resistance arteriole vascular smooth muscle cells (VSMCs) that are directly related to vasoconstriction has not been determined. Here we investigated the direct effect of exogenous CF6 on Ca(2+) signalling in cultured VSMCs and the in vivo role of endogenous CF6 in the genesis of hypertension using CF6 transgenic (TG) mice. CF6 induced a monophasic increase in the intracellular free Ca(2+) concentration ([Ca(2+)](i)) through nifedipine-sensitive Ca(2+) channels in A7r5 cells, a cell line of VSMCs, and enhanced the angiotensin II-induced spike phase of [Ca(2+)](i) to a greater degree in VSMCs derived from spontaneously hypertensive rats (SHRs). In the mesenteric arterioles obtained from CF6-TG mice that manifested hypertension, angiotensin II-induced vasoconstriction was enhanced, compared with wild-type mice, and its enhancement was abolished by an anti-CF6 antibody. Pre-treatment with PP1, a tyrosine kinase c-Src inhibitor, blocked CF6-induced increase in Ca(2+) signalling in VSMCs and vasoconstriction in TG mice. The receptor of CF6 was F(1) motor of adenosine triphosphate (ATP) synthase with a higher affinity in SHRs. CF6 decreased intracellular pH via activation of ATPase activity and led to c-Src activation to a greater degree in SHR-derived VSMCs. CF6 causes hypertension by directly enhancing Ca(2+) signalling in VSMCs and vasoconstriction in the mesenteric arteriolar network via c-Src activation.
  • Masanao Naya, Takahiro Tsukamoto, Koichi Morita, Chietsugu Katoh, Kenichi Nishijima, Hiroshi Komatsu, Satoshi Yamada, Yuji Kuge, Nagara Tamaki, Hiroyuki Tsutsui
    JOURNAL OF NUCLEAR MEDICINE 50 (2) 220 - 225 0161-5505 2009/02 [Refereed][Not invited]
     
    We evaluated whether myocardial P-adrenergic receptor (beta-AR) density, as determined by (11)C-CGP12177 PET, could predict improvement of cardiac function by P-blocker carvedilol treatment in patients with idiopathic dilated cardiomyopathy (IDC). Methods: Ten patients with IDC (left ventricular ejection fraction [LVEF] < 45%) were studied. Myocardial PAR density was estimated using (11)C-CGP12177 PET before treatment with carvedilol. Changes of LVEF in response to dobutamine infusion (ALVEF-dobutamine) were also measured by echocardiography. Changes of LVEF (Delta LVEF-carvedilol) were evaluated after 20 mo of carvedilol treatment. Results: Baseline myocardial PAR density significantly correlated with Delta LVEF-carvedilol (r = -0.88, P < 0.001). In contrast, Delta LVEF-clobutamine did not correlate with Delta LVEF-carvedilol (P = 0.65). Myocardial PAR density was the significant multivariate independent predictor of Delta LVEF-carvedilol (p = -0.88, P < 0.001) among univariate predictors, including functional class (r = 0.76, P < 0.05), plasma norepinephrine (r = 0.85, P < 0.01), LVEF (r = -0.64, P < 0.05), and age as confounding factors. Furthermore, myocardial PAR density was significantly correlated with plasma norepinephrine (r = -0.79, P < 0.01) and LVEF (r = 0.70, P < 0.05). Conclusion: Myocardial PAR density is more tightly related to improvement of LVEF-carvedilol than is cardiac contractile reserve in patients with IDC. Patients with decreased myocardial PAR have higher resting adrenergic drive, as reflected by plasma norepinephrine, and may receive greater benefit from being treated by antiadrenergic drugs.
  • A new PET scanner with semiconductor detector reveals intratumoral inhomogeneous cell activity with high spatial and energy resolution
    Shiga T, Kubo N, Morimoto Y, Katoh N, Katoh C, Ueno Y, Hirata K, Usui R, Kobayashi K, Takeuchi W, Shirato H, Tamaki N
    Molecular Imaging for Integrated Medical Therapy and Drug Development 42 - 51 2009 [Not refereed][Not invited]
  • Development of a prototype 3D PET scanner using semiconductor detectors and depth of interaction information
    Morimoto Y, Ueno Y, Kojima S, Takeuchi W, Ishitsu T, Matsuzaki K, Umegaki K, Kubo N, Katoh C, Zhao S, Shiga T, Tamaki N
    Molecular Imaging for Integrated Medical Therapy and Drug Development 30 - 41 2009 [Not refereed][Not invited]
  • Osamu Manabe, Keiichiro Yoshinaga, Chietsugu Katoh, Masanao Naya, Robert A deKemp, Nagara Tamaki
    Journal of nuclear medicine : official publication, Society of Nuclear Medicine 50 (1) 68 - 71 2009/01 [Refereed][Not invited]
     
    UNLABELLED: The repeatability of rest and hyperemic myocardial blood flow (MBF) measurements using 82Rb PET has not been evaluated. The aim of this study was to investigate the short-term repeatability of such measurements. METHODS: Fifteen healthy volunteers underwent rest and pharmacologic stress 82Rb PET, repeated 60 min apart. RESULTS: There was no significant difference in repeated rest MBF (0.77+/-0.25 vs. 0.82+/-0.25 mL/min/g, P=0.31; mean difference, 6.18%+/-12.22%) or repeated hyperemic MBF (3.35+/-1.37 vs. 3.39+/-1.37 mL/min/g, P=0.81; mean difference, 1.17%+/-13.64%). The repeatability coefficients were 0.19 mL/min/g for rest MBF and 0.92 mL/min/g for hyperemia. CONCLUSION: MBF using 82Rb is highly reproducible using a same-day short-term repeatability protocol. Serial MBF measurements with 82Rb PET should have the ability to quantify the acute effects of therapeutic interventions on MBF.
  • Tohru Shiga, Yuichi Morimoto, Naoki Kubo, Norio Katoh, Chietsugu Katoh, Wataru Takeuchi, Reiko Usui, Kenji Hirata, Shinichi Kojima, Kikuo Umegaki, Hiroki Shirato, Nagara Tamaki
    JOURNAL OF NUCLEAR MEDICINE 50 (1) 148 - 155 0161-5505 2009/01 [Refereed][Not invited]
     
    An autoradiography method revealed intratumoral inhomogeneity in various solid tumors. It is becoming increasingly important to estimate intratumoral inhomogeneity. However, with low spatial resolution and high scatter noise, it is difficult to detect intratumoral inhomogeneity in clinical settings. We developed a new PET system with CdTe semiconductor detectors to provide images with high spatial resolution and low scatter noise. Both phantom images and patients' images were analyzed to evaluate intratumoral inhomogeneity. Methods: This study was performed with a cold spot phantom that had 6-mm-diameter cold sphenoid defects, a dual-cylinder phantom with an adjusted concentration of 1:2, and an "H"-shaped hot phantom. These were surrounded with water. Phantom images and (18)F-FDG PET images of patients with nasopharyngeal cancer were compared with conventional bismuth germanate PET images. Profile curves for the phantoms were measured as peak-to-valley ratios to define contrast. Intratumoral inhomogeneity and tumor edge sharpness were evaluated on the images of the patients. Results: The contrast obtained with the semiconductor PET scanner (1.53) was 28% higher than that obtained with the conventional scanner (1.20) for the 6-mm-diameter cold sphenoid phantom. The contrast obtained with the semiconductor PET scanner (1.43) was 27% higher than that obtained with the conventional scanner (1.13) for the dual-cylinder phantom. Similarly, the 2-mm cold region between 1-mm hot rods was identified only by the new PET scanner and not by the conventional scanner. The new PET scanner identified intratumoral inhomogeneity in more detail than the conventional scanner in 6 of 10 patients. The tumor edge was sharper on the images obtained with the new PET scanner than on those obtained with the conventional scanner. Conclusion: These phantom and clinical studies suggested that this new PET scanner has the potential for better identification of intratumoral inhomogeneity, probably because of its high spatial resolution and low scatter noise.
  • Akiko Kumagai, Tomohiro Osanai, Chisato Katoh, Makoto Tanaka, Hirofumi Tomita, Takeshi Morimoto, Reiichi Murakami, Koji Magota, Ken Okumura
    ATHEROSCLEROSIS 200 (1) 45 - 50 0021-9150 2008/09 [Refereed][Not invited]
     
    Coupling factor 6 (CF6), a component of ATP synthase, suppresses the generation of prostacyclin and nitric oxide (NO). Platelet endothelial cell adhesion molecule-1 (PECAM-1) is involved in shear-induced NO production. To investigate the linkage between the actions of CF6 and PECAM-1, we examined the effects of CF6 on PECAM-1 expression and shear-mediated NO release, comparatively with those of angiotensin II (AngII). Treatment of human umbilical vein endothelial cells (HUVEC) and aortic endothelial cells (HAEC) with CF6 at 10(-7) M or AngII at 10(-7) M for 24 h suppressed PECAM-1 gene and protein expression. CF6 or AngII activated c-Src at 15 min in HUVEC, and blockade of c-Src with PP1, its specific inhibitor, restored them. Efrapeptin, an inhibitor of ATPase, attenuated CF6-induced suppression of PECAM-1 gene expression by blockade of acidification, whereas superoxide dismutase or apocinin, an inhibitor of NADPH oxidase, blocked AngII-induced suppression of PECAM-1. Exposure of the cells to shear stress at 25 dynes/cm(2) for 30 min enhanced phosphorylation of eNOS at Ser(1177) and NO release. Pretreatment with CF6 or AngII for 24 h attenuated them in HUVEC and HAEC. These suggest that CF6 downregulates PECAM-1 expression via c-Src activation and attenuates shear-induced NO release presumably by suppressing eNOS phosphorylation. (C) 2007 Elsevier Ireland Ltd. All rights reserved.
  • Tomoya Kohno, Tohru Shiga, Atsuhito Toyomaki, Ichiro Kusumi, Tetsuaki Matsuyama, Tetsuya Inoue, Chietsugu Katoh, Tsukasa Koyama, Nagara Tamaki
    JOURNAL OF CLINICAL PSYCHOPHARMACOLOGY 27 (6) 698 - 702 0271-0749 2007/12 [Refereed][Not invited]
     
    Lithium is clinically available for the treatment of mood disorders. However, it has remained unclear how lithium acts on the brain to produce its effects. The aim of this study was to evaluate the effects of chronic lithium on human brain activity using positron emission tomography and clarify the correlation between brain activity changes and cognitive functional changes as induced by chronic lithium administration. A total of 20 healthy male subjects (mean age, 32 6 years) underwent positron emission tomographic scans with F-18-fluorodeoxyglucose and a battery of neuropsychological tests at baseline condition and after 4 weeks of lithium administration. Brain metabolic data were analyzed using statistical parametric mapping. Lithium increased relative regional cerebral glucose metabolism (rCMRglc) in the bilateral dorsomedial frontal cortices including the anterior cingulate gyrus and decreased rCMRglc in the right cerebellum and left lingual gyrus/cuneus. There was no difference in any of the variables of cognitive functions between the baseline condition and after chronic lithium administration. There was no correlation between rCMRglc changes in any of the brain regions and individual variable changes in any of the neuropsychological tests. The results suggest that the effects of chronic lithium are associated with increased activity in the bilateral dorsomedial frontal cortices including the anterior cingulate gyros and decreased activity in the right cerebellum and left lingual gyrus/cuneus.
  • Takahiro Tsukamoto, Koichi Morita, Masanao Naya, Masayuki Inubushi, Chietsugu Katoh, Kenichi Nishijima, Yuji Kuge, Hiroshi Okamoto, Hiroyuki Tsutsui, Nagara Tamaki
    JOURNAL OF NUCLEAR MEDICINE 48 (11) 1777 - 1782 0161-5505 2007/11 [Refereed][Not invited]
     
    Cardiac sympathetic function plays an important role in the regulation of left ventricular (LV) function and the pathophysiology of LV dysfunction. C-11-CGP-12177 (C-11-CGP) has been used to assess myocardial beta-adrenergic receptor (P-AR) density in vivo using PET. The aim of this study is to measure myocardial P-AR density in patients with nonischemic cardiomyopathy and to compare the measurements with various standard parameters of heart failure (HF), particularly with presynaptic function assessed by I-123-metaiodobenzy(guanidine (I-123-MIBG) imaging. Methods: C-11-CGP PET was performed on 16 patients with nonischemic cardiomyopathy and 8 age-matched healthy volunteers using a double injection method. A C-11-CGP dynamic scan for 75 min was performed after the injection of C-11-CGP with a high specific activity. After 30 min, C-11-CGP with a low specific activity was injected. The P-AR density of the whole LV was calculated on the basis of the graphical analysis method. Additionally, beta-AR density was compared with LV ejection fraction (LVEF), sympathetic presynaptic function assessed using I-123-MIBG kinetics, and neurohormonal parameters. Results: The P-AR density of patients was significantly lower than that of healthy volunteers (3.80 +/- 0.96 vs. 7.70 +/- 1.92 pmol/mL; P < 0.0001). In the patients, P-AR density correlated significantly with LVEF (r = 0.62, P < 0.05). Furthermore, P-AR density correlated significantly with the I-123-MIBG washout rate (r = -0.68, P < 0.01) and delayed heart-to-mediastinum ratio (H/M ratio) (r = 0.61, P < 0.05). On the other hand, the correlation between P-AR density and early H/M ratio was not significant (r = 0.40, P = 0.13). The beta-AR density of patients with severe HF (New York Heart Association functional [NYHA] class III) was significantly lower than that of those with NYHA functional class I or class II HIF (3.24 +/- 0.96 vs. 4.24 +/- 0.73 pmol/mL; P < 0.05). Conclusion: A reduction in P-AR density measured by C-11-CGP PET was observed in patientswith nonischemic cardiomyopathy. This downregulation may be due to the increased presynaptic sympathetic tone as assessed by I-123-MIBG imaging.
  • Masanao Naya, Takahiro Tsukamoto, Koichi Morita, Chietsugu Katoh, Tornoo Furumoto, Satoshi Fujii, Nagara Tamaki, Hiroyuki Tsutsui
    JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY 50 (12) 1144 - 1149 0735-1097 2007/09 [Refereed][Not invited]
     
    Objectives We aimed to compare the effects of the angiotensin II receptor blocker (ARB) olmesartan versus the calcium channel blocker (CCB) amlodipine on coronary endothelial dysfunction in patients with hypertension. Background Angiotensin II receptor blockers are thought to have greater beneficial effects than CCBs on coronary vasomotion by directly blocking action of angiotensin II. Methods Twenty-six patients with untreated essential hypertension were prospectively assigned to treatment with either olmesartan (27.7 +/- 12.4 mg/day, n = 13) or amlodipine (5.6 +/- 1.5 mg/day, n = 13) for 12 weeks. Changes of corrected myocardial blood flow (Delta MBF) and coronary vascular resistance (Delta CVR) from rest to cold pressor were measured by using O-15-water and positron emission tomography before and after treatment. Blood biomarkers including lipids, glucose, insulin, high-sensitivity C-reactive protein, interleukin-6, tumor necrosis factor-alpha, and superoxide dismutase (SOD) were also measured. Results Olmesartan and amlodipine reduced blood pressure (BP) to the same extent (-28.7 +/- 16.2 mm Hg vs. -26.7 +/- 10.8 mm Hg). In the olmesartan group, Delta MBF tended to be greater (-0.15 +/- 0.19 ml/g/min vs. 0.03 +/- 0.17 ml/g/min, p = 0.09 by 2-way analysis of variance), and Delta CVR was significantly decreased (7.9 +/- 23.5 mm Hg/[ml/g/min] vs. -16.6 +/- 18.0 mm Hg/[ml/g/min], p < 0.05) after treatment, whereas these parameters did not change in the amlodipine group (Delta MBF: -0.15 - 0.12 ml/g/min vs. -0.12 +/- 0.20 ml/g/min; Delta CVR: 6.5 +/- :18.2 mm Hg/[ml/g/min] vs. 4.8 +/- 23.4 mm Hg/[ml/g/min]). Serum SOD activity tended to increase (4.74 +/- 4.77 U/ml vs. 5.57 +/- 4.74 U/ml, p = 0.07 by 2-way analysis of variance) only in the olmesartan group. Conclusions Olmesartan, but not amlodipine, improved endothelium-dependent coronary dilation in hypertensive patients independent of BP reduction. These beneficial effects on coronary vasomotion might be via an antioxidant property of ARBs.
  • Masanao Naya, Takahiro Tsukamoto, Koichi Morita, Chietsugu Katoh, Tomoo Furumoto, Satoshi Fujii, Nagara Tamaki, Hiroyuki Tsutsui
    HYPERTENSION RESEARCH 30 (6) 541 - 548 0916-9636 2007/06 [Refereed][Not invited]
     
    Coronary endothelial function is impaired in hypertension; however, the severity of this impairment varies among patients. We aimed to identify the predictors of coronary endothelial dysfunction among clinical variables related to hypertension and atherosclerosis. Twenty-seven untreated, uncomplicated essential hypertensive patients and 10 age-matched healthy controls were studied prospectively. Myocardial blood flow (MBF) was measured by using O-15-water positron emission tomography (PET) at rest and during a cold pressor test (CPT). Coronary vascular resistance (CVR) during CPT was used as a marker of coronary endothelial function. Serum low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, triglycerides, malondialdehyde-LDL, homeostasis model assessment, high-sensitivity C-reactive protein (hs-CRP), and plasma interleukin-6 (IL-6) and tumor necrosis factor (TNF)-alpha were also measured. CVR during CPT was significantly higher in hypertensive patients than in healthy controls (114 +/- 26 vs. 94 +/- 12 mmHg/[mL/g/min]; p<0.05). By univariate analysis, CVR during CPT was correlated with LDL cholesterol (r=0.38, p<0.05), IL-6 (r=0.46, p<0.02), and TNF-alpha (r=0.39, p<0.05) in hypertensive patients. By multivariate analysis, IL-6 and TNF-a were significant independent predictors of CVR during CPT. Elevated plasma IL-6 and TNF-alpha levels were independent predictors of coronary endothelial dysfunction in hypertensive patients. These results suggest that plasma IL-6 and TNF-alpha might be useful for identifying the high risk subgroup of hypertensive patients with coronary endothelial dysfunction and provide an important clue to link systemic inflammation to the development of coronary atherosclerosis.
  • Masanao Naya, Takahiro Tsukamoto, Masayuki Inubushi, Koichi Morita, Chietsugu Katoh, Tomoo Furumoto, Satoshi Fujii, Hiroyuki Tsutsui, Nagara Tamaki
    CIRCULATION JOURNAL 71 (3) 348 - 353 1346-9843 2007/03 [Refereed][Not invited]
     
    Background Elevated plasma plasminogen activator inhibitor-1 (PAI-1) is related to cardiovascular events, but its role in subclinical coronary microvascular. dysfunction remains unknown. Thus, in the present study it was investigated whether elevated plasma PAI-1 activity is associated with coronary microvascular dysfunction in hypertensive patients. Methods and Results Thirty patients with untreated essential hypertension and 10 age-matched healthy controls were studied prospectively. Myocardial blood flow (MBF) was measured by using O-15-water positron emission tomography. Clinical variables associated with atherosclerosis (low-density lipoprotein-cholesterol, high-density lipoprotein (HDL)-cholesterol, triglyceride, homeostasis model assessment (HOMA-IR), and PAI-1 activity) were assessed to determine their involvement in coronary microvascular dysfunction. Adenosine triphosphate (ATP)-induced hyperemic MBF and coronary flow reserve (CFR) were significantly lower in hypertensive patients than in healthy controls (ATP-induced MBF: 2.77 +/- 0.82 vs 3.49 +/- 0.71 ml (.) g(-1) (.) min(-1); p < 0.02 and CFR: 2.95 +/- 1.06 vs 4.25 +/- 0.69; p < 0.001). By univariate analysis, CFR was positively correlated with HDL-cholesterol (r=0.46, p < 0.02), and inversely with HOMA-IR (r=-0.39, p < 0.05) and PAI-1 activity (r=-0.61, p < 0.001). By multivariate analysis, elevated PAI-1 activity remained a significant independent determinant of diminished CFR. Conclusions Elevated plasma PAI-1 activity was independently associated with coronary microvascular dysfunction, which suggests that plasma PAI-1 activity is an important clue linking hypofibrinolysis to the development of atherosclerosis.
  • 穂刈正昭, 黒田敏, 志賀哲, 加藤千恵次, 中山若樹, 玉木長良, 岩崎喜信
    脳循環代謝 19 (2) 84  0915-9401 2007 [Not refereed][Not invited]
  • 3H‐FLTによる癌の分子標的療法の早期評価:担がんマウスにおける投与量依存性の検討
    趙松吉, 趙松吉, 久下裕司, 久下裕司, 趙芫, 竹井俊樹, 鐘ケ江香久子, 犬伏正幸, 志賀哲, 加藤千恵次, 関興一, 玉木長良
    核医学 44 (3) 294  2007 [Not refereed][Not invited]
  • 細胞増殖能評価,腫瘍‐肉芽腫の鑑別診断における11C‐methionineと18F‐FDGの比較
    趙松吉, 趙松吉, 久下裕司, 久下裕司, 趙芫, 竹井俊樹, 加藤誠一, 鐘ケ江香久子, 岡本祥三, 加藤千恵次, 関興一, 玉木長良
    核医学 44 (3) 262  2007 [Not refereed][Not invited]
  • Tohru Shiga, Tomohito Kaji, Tomoya Kohno, Hiroyuki Kageyama, Chietsugu Katoh, Jun Hatazawa, Naohiko Oku, Isamu Narabayashi, Hitoya Ohta, Tsuyoshi Komori, Masuo Hayashi, Nagara Tamaki
    Kakuigaku 44 (1) 1 - 7 0022-7854 2007 [Refereed][Not invited]
     
    To confirm the previous reports demonstrating the difference in the octanol extraction fractions between the currently available two N-isopropyl-4- iodoamphetamine (123I) products (IMPA and IMP B), we newly developed the standard input function for IMP B in 19 healthy volunteers and compared it with the established standard input function, which has been originally generated with IMP A. The octanol extraction fractions of IMPB were stable from 5 minutes to 16 minutes post injection and significantly higher than those of IMPA. The mCBFs calculated with IMPB by using the established stan-dard input function for IMPA tended to be higher than those with the combination of IMPA and the established standard input function though the difference was not significant. When measured with IMPB combined with the correspondent standard input function, mCBFs were identical to those calculated with IMPA with the established standard input function, suggesting that the appropriate standard input function should be used according to the product used.
  • Koichi Morita, Takahiro Tsukamoto, Masanao Naya, Kazuyuki Noriyasu, Masayuki Inubushi, Tohru Shiga, Chietsugu Katoh, Yuji Kuge, Hiroyuki Tsutsui, Nagara Tamaki
    JOURNAL OF NUCLEAR MEDICINE 47 (12) 1914 - 1920 0161-5505 2006/12 [Refereed][Not invited]
     
    Cigarette smoking is one of the risk factors of cardiovascular diseases and is related to abnormal peripheral and coronary vascular vasomotion. Coronary vascular endothelial dysfunction is caused by chronic smoking in smokers without epicardial coronary artery stenosis. The coronary endothelial vasomotion abnormality is restored by interventions such as L-arginine or vitamin C infusion. However, to our knowledge, the effect of smoking cessation on coronary vasomotor response has not been elucidated. Therefore, the aim of this study was to assess the effect of smoking cessation on coronary vasomotor response by quantitative myocardial blood flow (MBF) measurement using O-15-water and PET. Methods: Fifteen young smokers (Brinkman index > 100; mean age +/- SD, 26 +/- 4 y) with no evidence of heart disease or cardiovascular risk factors, except for smoking, and age-matched nonsmokers (n = 12) were enrolled in this study. MBF was measured at rest, during the cold pressor test (CPT), before and at 1 and 6 mo after smoking cessation. In addition, MBF measurement during adenosine triphosphate (ATP) infusion was performed before and at 6 mo after smoking cessation. In nonsmokers, MBF was measured at rest, during ATP infusion, and during the CPT. Results: MBF at rest and during ATP infusion did not differ between smokers and nonsmokers (0.73 +/- 0.12 vs. 0.80 +/- 0.15 mLg/min and 3.15 +/- 1.43 vs. 3.69 +/- 0.76 mL/g/min, respectively; P = not significant). In contrast, MBF during the CPT in smokers was lower than that in nonsmokers (0.90 +/- 0.19 vs. 1.12 +/- 0.28 mUg/min; P < 0.05). There was no significant difference in MBF either at rest or during ATP infusion between before and after smoking cessation, but MBF during the CPT increased at 1 mo in comparison with before cessation of smoking (0.90 +/- 0.19 vs. 1.02 +/- 0.22 mUg/min; P < 0.01). An improvement of MBF response to the CPT was preserved at 6 mo after smoking cessation. Conclusion: Coronary vasomotor abnormality assessed by MBF response to the CPT was improved at 1 mo after smoking cessation. These findings indicate that coronary endothelial dysfunction may be reversible within 1 mo after smoking cessation in healthy young smokers.
  • Takahiro Tsukamoto, Koichi Morita, Masanao Naya, Chietsugu Katoh, Masayuki Inubushi, Yuji Kuge, Hiroyuki Tsutsui, Nagara Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 33 (10) 1150 - 1156 1619-7070 2006/10 [Refereed][Not invited]
     
    Purpose: Myocardial flow reserve (MFR) measurement has an important role in assessing the functional severity of coronary artery stenosis. However, a discrepancy between the anatomical severity of coronary artery stenosis and MFR is often observed. Such a discrepancy may be explained by coronary risk factors. In this study, we aimed to investigate the influence of coronary artery stenosis severity and risk factors on MFR. Methods: Seventy-four patients suspected to have coronary artery disease and seven age-matched healthy volunteers were enrolled. Myocardial blood flow (MBF) and MFR were measured using O-15-labelled water PET. Regional MFR was calculated in regions with significant coronary artery stenosis (stenotic regions) and in regions without significant stenosis (remote regions). The contributions of coronary artery stenosis severity and coronary risk factors were assessed using univariate and multivariate analyses. Results: In stenotic regions, MFR correlated inversely with coronary artery stenosis severity (r=-0.50, p < 0.01). Univariate analysis did not show any significant difference in MFR between the patients with and the patients without each risk factor. In remote regions, however, MFR was significantly decreased in the diabetes and smoking groups (each p < 0.05). By multivariate analysis, diabetes and smoking were independent predictors of MFR (each p < 0.05). In the group with more than one risk factor, MFR was significantly lower (2.78 +/- 0.79) than in the other group (3.40 +/- 1.22, p < 0.05). Conclusion: MFR is influenced not only by coronary stenosis severity but also by coronary risk factors. In particular, the influence of risk factors should be considered in regions without severe coronary stenosis.
  • Tomoya Kohno, Tohru Shiga, Ichiro Kusumi, Tetsuaki Matsuyama, Hiroyuki Kageyama, Chietsugu Katoh, Tsukasa Koyama, Nagara Tamaki
    PSYCHIATRY RESEARCH-NEUROIMAGING 147 (2-3) 163 - 171 0925-4927 2006/10 [Refereed][Not invited]
     
    We evaluated the relationship between regional cerebral blood flow (rCBF) and clinical symptoms in patients with schizophrenia. Single photon emission computed tomography with N-isopropyl-p-[ (123)]iodoamphetamine (I-123-IMP) was used to study 29 patients with schizophrenia. Clinical symptoms were assessed using the Brief Psychiatric Rating Scale (BPRS). We examined the correlation between rCBF and each BPRS item score using Statistical Parametric Mapping software. Corrected P-values < 0.05 were considered as statistically significant. The suspiciousness score on the BPRS was positively correlated with rCBF in the left inferior temporal gyrus. There was no significant correlation between rCBF and any other items of the BPRS. There was no significant correlation between rCBF and chlorpromazine-equivalent dosage. This analysis permits the quantitative assessment of the severity of persecutory delusions in relation to left temporal perfusion in patients with schizophrenia. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
  • T Shiga, K Ikoma, C Katoh, H Isoyama, T Matsuyama, Y Kuge, H Kageyama, T Kohno, S Terae, N Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 33 (7) 817 - 822 1619-7070 2006/07 [Refereed][Not invited]
     
    Purpose: Traumatic brain injury (TBI) causes brain dysfunction in many patients. However, some patients have severe brain dysfunction but display no abnormalities on magnetic resonance imaging (MRI). There have been some reports of hypometabolism even in such patients. The purpose of this study was to investigate the relationship between metabolic abnormality and loss of neuronal integrity in TBI patients with some symptoms but without MRI abnormalities. Methods: The study population comprised ten patients with TBI and ten normal volunteers. All of the patients were examined at least 1 year after the injury. O-15-labelled gas PET and [C-11]flumazenil (FMZ) positron emission tomography (PET) were carried out. The cerebral metabolic rate of oxygen (CMRO2) and binding potential (BP) images of FMZ were calculated. Axial T2WI, T2*WI and FLAIR images were obtained. Coronal images were added in some cases. Results: All of the patients had normal MRI findings, and all showed areas with abnormally low CMRO2. Low uptake on BP images was observed in six patients (60%). No lesions that showed low uptake on BP images were without low CMRO2. On the other hand, there were 14 lesions with low CMRO2 but without BP abnormalities. Conclusion: These results indicate that there are metabolic abnormalities in TBI patients with some symptoms after brain injury but without abnormalities on MRI. Some of the hypometabolic lesions showed low BP, indicating a loss of neuronal integrity. Thus, FMZ PET may have potential to distinguish hypometabolism caused by neuronal loss from that caused by other factors.
  • 半導体検出器が装備された小視野PET装置の基礎的検討
    久保直樹, 趙松吉, 加藤千恵次, 上野雄一郎, 森本裕一, 雨宮健介, 梅垣菊男, 犬伏正幸, 玉木長良
    核医学 43 (3) 244  2006 [Not refereed][Not invited]
  • 半導体検出器を使用した小被写体用PET装置の基本性能とその評価について
    久保直樹, 加藤千恵次, 玉木長良, 趙松吉, 森本裕一, 上野雄一郎, 北口博司, 土屋一俊, 小嶋進一, 梅垣菊男
    核医学 43 (4) 343  2006 [Not refereed][Not invited]
  • H Kageyama, K Morita, C Katoh, T Tsukamoto, K Noriyasu, M Mabuchi, M Naya, Y Kawai, N Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 33 (1) 6 - 12 1619-7070 2006/01 [Refereed][Not invited]
     
    Purpose: Long-chain fatty acid (LCFA) is the main energy source for normal myocardium at rest, but in ischemic myocardium, the main energy substrate shifts from LCFA to glucose. I-123\-BMIPP is a radiolabeled LCFA analog. In chronic stable angina without previous infarction, we suppose that reduced I-123\-BMIPP uptake is related to the substrate shift in myocardium with decreased myocardial flow reserve (MFR). The purpose of this study was to relate I-123-BMIPP uptake to rest myocardial blood flow (MBF), hyperemic MBF, and MFR assessed with O-15-water positron emission tomography ( PET). Methods: We enrolled 21 patients with chronic stable angina without previous infarction, all of whom underwent I-123-BMIPP single-photon emission computed tomography (SPECT) and O-15-water PET. The left ventricle was divided into 13 segments. In each segment, rest MBF and hyperemic MBF were measured by PET. I-123-BMIPP uptake was evaluated as follows: score 0= normal, 1= slightly decreased uptake, 2= moderately decreased uptake, 3= severely decreased uptake, and 4= complete defect. I-123\-BMIPP uptake was compared with rest MBF, hyperemic MBF, and MFR. Results: The numbers of segments with I-123-BMIPP scores 0, 1, 2, 3, and 4 were 178, 40, 25, 24, and 0, respectively. The rest MBFs for scores 0, 1, 2, and 3 were 0.93 +/- 0.25, 0.86 +/- 0.21, 0.97 +/- 0.30, and 0.99 +/- 0.37 ml/min/g, respectively. The hyperemic MBFs for scores 0, 1, 2, and 3 were 2.76 +/- 1.29, 1.84 +/- 0.74, 1.37 +/- 0.39, and 1.08 +/-= 0.40 ml/min/g, respectively. The MFRs for scores 0, 1, 2, and 3 were 3.01 +/- 1.38, 2.20 +/- 0.95, 1.44 +/- 0.22, and 1.10 +/- 0.26, respectively. As I-123-BMIPP uptake declined, hyperemic MBF and MFR decreased. Conclusion: In chronic stable angina without previous infarction, reduced I-123-BMIPP uptake implies decreased MFR.
  • N Kubo, S Zhao, Y Fujiki, A Kinda, N Motomura, C Katoh, T Shiga, H Kawashima, Y Kuge, N Tamaki
    ANNALS OF NUCLEAR MEDICINE 19 (7) 633 - 639 0914-7187 2005/10 [Refereed][Not invited]
     
    Objectives: Small animal imaging has recently been focused on basic nuclear medicine. We have designed and built a small animal SPECT imaging system using a semiconductor camera and a newly designed collimator. We assess the performance of this system for small object imaging. Methods: We employed an MGC1500 (Acrorad Co.) camera including a CdTe semiconductor. The pixel size was 1.4 mm/pixel. We designed and produced a parallel-hole collimator with 20-mm hole length. Our SPECT system consisted of a semiconductor camera with the subject holder set on an electric rotating stage controlled by a computer. We compared this system with a conventional small animal SPECT system comprising a SPECT-2000H scanner with four Anger type cameras and pinhole collimators. The count rate linearity for estimation of the scatter was evaluated for a pie-chart phantom containing different concentrations of Tc-99m. We measured the FWHM of the Tc-99m SPECT line source along with scatter. The system volume sensitivity was examined using a flood source phantom which was 35 mm long with a 32-mm inside diameter. Additionally, an in vivo myocardial perfusion SPECT study was performed with a rat. Results: With regards to energy resolution, the semiconductor camera (5.6%) was superior to the conventional Anger type camera (9.8%). In the count rate linearity evaluation, the regression lines of the SPECT values were y = 0.019x + 0.031 (r(2) = 0.999) for our system and y = 0.018x + 0.060 (r(2) = 0.997) for the conventional system. Thus, the scatter count using the semiconductor camera was less than that using the conventional camera. FWHMs of our system and the conventional system were 2.9 +/- 0.1 and 2.0 +/- 0.1 mm, respectively. Moreover, the system volume sensitivity of our system [0.51 kcps/(MBq/ml)/cm] was superior to that of the conventional system [0.44 kcps/(MBq/ml)/cm]. Our system provided clear images of the rat myocardium, sufficient for practical use in small animal imaging. Conclusions: Our SPECT system, utilizing a semiconductor camera, permits high quantitative analysis by virtue of its low scatter radiation and high sensitivity. Therefore, this system may contribute to molecular imaging of small animals and basic medical research.
  • T. Noji, S. Okushiba, S. Kitashiro, Y. Kawarada, T. Shichinohe, S. Kondo, H. Katoh
    Diseases of the Esophagus 18 (3) 204 - 206 1120-8694 2005/08 [Refereed][Not invited]
     
    We report a case of aorto esophageal fistula (AEF) with delayed esophageal reconstruction employing microvascular anastomosis. We demonstrate here that our method is useful for delayed esophageal reconstruction following AEF. © 2005 ISDE.
  • K Morita, C Katoh, K Yoshinaga, K Noriyasu, M Mabuchi, T Tsukamoto, H Kageyama, T Shiga, Y Kuge, N Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 32 (7) 806 - 812 1619-7070 2005/07 [Refereed][Not invited]
     
    Purpose: Myocardial glucose utilization (MGU) is altered in various heart diseases. The aim of this study was to quantitatively assess regional myocardial glucose utilization in patients with left ventricular (LV) dysfunction by dynamic F-18-fluorodeoxyglucose positron emission tomography (FDG PET). Methods: A total of 18 subjects were studied, including ten with LV dysfunction ( seven with idiopathic dilated cardiomyopathy and three with aortic regurgitation; NYHA II in 8 and III in 2) and eight healthy normal volunteers. Patients with diabetes mellitus were excluded. A dynamic PET study was performed for 40 min following the injection of 370 MBq of FDG after 50-g glucose loading. On the basis of a three-compartment model, MGU, K-1, k(2), and k(3) were computed on a pixel by pixel basis to generate LV myocardial parametric maps. FDG standardized uptake value (SUV) was also calculated using static images obtained 40 min after FDG injection. These metabolic values were compared with myocardial flow distribution (% Flow), LVEF, LV volumes, and LV wall thickening (WT) determined by gated myocardial single-photon emission computed tomography using QGS software in eight myocardial segments. Results: MGU correlated positively with LV volumes and negatively with LVEF. K1 was significantly higher in the segments of the patients than in those of the normal volunteers ( 0.082 +/- 0.055 vs 0.041 +/- 0.017 ml min(-1) g(-1), p< 0.05), although there was no difference in MGU between the groups. On the other hand, SUV, k(2), and k(3) did not differ significantly between the groups. Among the patients, the K-1 values were significantly higher in the areas with impaired WT (% WT< 17%) (0.109 +/- 0.063 vs 0.069 +/- 0.062 ml min(-1) g(-1), p< 0.05) and in the areas with flow reduction (% Flow< 71%) (0.112 +/- 0.076 vs 0.071 +/- 0.046 ml min(-1) g(-1), p< 0.05). Conclusion: These results indicate that glucose utilization was preserved in the patients with LV dysfunction, mainly due to an increase in glucose transport, particularly in the regions with severely impaired LV function. Thus, the quantitative assessment of myocardial glucose utilization by FDG dynamic PET may provide useful information for assessing the regional myocardial metabolic status in patients with LV dysfunction.
  • 頭頸部腫瘍における放射線治療前FDG-PETの検討 SUVの意義について
    鈴木 恵士郎, 西岡 健, 青山 英史, 土屋 和彦, 白土 博樹, 宮坂 和男, 加藤 千恵次, 志賀 哲, 中駄 邦博, 玉木 長良
    日本医学放射線学会学術集会抄録集 (公社)日本医学放射線学会 64回 S298 - S299 0048-0428 2005/02
  • T Tsukamoto, Y Ito, K Noriyasu, K Morita, C Katoh, H Okamoto, N Tamaki
    CIRCULATION JOURNAL 69 (2) 188 - 193 1346-9843 2005/02 [Refereed][Not invited]
     
    Background The aims of this study were to develop a method for quantitative estimation of the myocardial blood flow index (MBFI) and myocardial flow reserve (MFR) of the whole left ventricle using (99m)technetium (Tc-99m)-sestamibi imaging. Methods and Results Twenty-two patients with suspected coronary artery disease and 7 controls underwent both Tc-99m-sestamibi imaging and O-15 water positron emission tomography (PET). The global MBFI was calculated on the basis of the microsphere model from the ratio of the myocardial count to the area under the time-activity curve on the aortic arch. The regional MBFI was calculated from the relative distributions of Tc-99m-sestamibi uptake values. The regional MBFI and MFR (Tc-MFR) obtained using single-photon emission computed tomography were compared with the myocardial blood flow (MBF) and MFR (PET-MFR) obtained using PET as the gold standard. Regional MBFI significantly correlated with the MBF obtained using PET. Regional Tc-MFR also correlated with the regional PET-MFR, with some underestimation. Conclusion These results indicate that regional MBF and MFR may be estimated by dynamic Tc-99m-sestamibi imaging and can be used for the early detection and estimation of the functional severity of coronary lesions without the need for a PET camera.
  • Cerebral oxygen metabolism and neuronal integrity in patients with impaired vasoreactivity attributable to occlusive carotid artery disease.
    Kuroda S, Shiga T, Houkin K, Ishikawa T, Katoh C, Tamaki N, Iwasaki Y
    Stroke. 37 (2) 393 - 398 2005/02 [Refereed][Not invited]
     
    Kuroda S, Shiga T, Houkin K, Ishikawa T, Katoh C, Tamaki N, Iwasaki Y.
    Cerebral oxygen metabolism and neuronal integrity in patients with impaired vasoreactivity attributable to occlusive carotid artery disease.
    Stroke. 2006 Feb;37(2):393-8. Epub 2005 Dec 29.*
  • 越智 伸司, 佐藤 修治, 伊藤 禎洋, 青木 ともえ, 西原 徹, 山口 聖武, 塚本 江利子, 加藤 千恵次
    日本放射線技術学会雑誌 公益社団法人 日本放射線技術学会 61 (9) 1267 - 1267 2005
  • K Yoshinaga, C Katoh, RSB Beanlands, K Noriyasu, K Komuro, S Yamada, Y Kuge, K Morita, A Kitabatake, N Tamaki
    JOURNAL OF NUCLEAR MEDICINE 45 (11) 1885 - 1891 0161-5505 2004/11 [Refereed][Not invited]
     
    The recovery of function in myocardium defined as viable by F-18-FDG PET may differ from that defined by dobutamine stress echocardiography (DSE). The aim of this study was to investigate the difference in the oxidative metabolic response between myocardial segments with preserved contractile reserve (CR) and those without CR, in segments with and without preserved glucose metabolism (GM), using C-11-acetate PET. Methods: Twenty patients with previous myocardial infarction (left ventricular ejection fraction, 37.1% +/- 16.5%) underwent dynamic C-11-acetate PET at rest and during dobutamine (7.5 mug/kg/min) infusion. GM was evaluated using 18F-FDG PET and CR was evaluated using DSE. Dysfunctional segments were divided into 3 groups: group A (n = 26) with preserved CR and GM, group B (n = 15) without CR but with preserved GM, and group C (n = 41) without CR and without preserved GM. Results: Resting oxidative metabolism (k mono = monoexponential clearance rate) was preserved in group A and group B (0.052 +/- 0.011/min vs. 0.051 +/- 0.012/min, P = not significant) but was reduced in group C (0.040 +/- 0.015/min) (P < 0.03 vs. group A and group B). The change in k mono, as a measure of the metabolic response to low-dose dobutamine, was significantly higher in group A (0.018 +/- 0.012) than that in group B (0.0075 +/- 0.0096, P < 0.03) and group C (0.0080 +/- 0.012, P < 0.005). Conclusion: Viable segments based on F-18-FDG PET have preserved resting oxidative metabolism. However, segments without CR but with preserved GM show a reduction in the oxidative metabolic response to low-dose dobutamine infusion. The decrease in CR may be related to the reduction in the metabolic response to inotropic stimulation despite preservation of tissue viability on F-18-FDG PET.
  • C Katoh, K Morita, T Shiga, N Kubo, K Nakada, N Tamaki
    JOURNAL OF NUCLEAR MEDICINE 45 (11) 1908 - 1916 0161-5505 2004/11 [Refereed][Not invited]
     
    O-15-Water and dynamic PET allow noninvasive quantification of myocardial blood flow (MBF). However, complicated image analyzing procedures are required, which may limit the practicality of this approach. We have designed a new practical algorithm, which allows stable, rapid, and automated quantification of regional MBF (rMBF) using O-15-water PET. We designed an algorithm for setting the 3-dimensional (3D) region of interest (ROI) of the whole myocardium semiautomatically. Subsequently, a uniform input function was calculated for each subject using a time-activity curve in the 3D whole myocardial ROI. The uniform input function allows the mathematically simple and robust algorithm to estimate rMBF. Methods: Thirty-six volunteers were used in the static O-15-CO and dynamic O-15-water PET studies. To evaluate the reproducibility of the estimates, a repeated O-15-water scan was obtained under resting condition. In addition, to evaluate the stability of the new algorithm in the hyperemic state, a O-15-water scan was obtained with adenosine triphosphate. This algorithm includes a procedure for positioning a 3D ROI of the whole myocardium from 3D images and dividing it into 16 segments. Subsequently, the uniform input function was calculated using time-activity curves in the whole myocardial ROI and in the LV ROI. The uniform input function allowed this simple and robust algorithm to estimate the rMBF, perfusable tissue fraction (PTF), and spillover fraction (Va) according to a single tissue compartment model. These estimates were compared with those calculated using the original method. A simulation study was performed to compare the effects of errors in PTF or Va on the MBF using the 2 methods. Results: The average operating time for positioning a whole myocardial ROI and 16 regional myocardial ROIs was <5 min. The new method yielded less deviation in rMBF (0.876 +/- 0.177 mL/min/g, coefficient of variation [CV] =20.2%, n = 576) than those with the traditional method (0.898 +/- 0.271 mL/min/g, CV = 30.1 %, n = 576) (P < 0.01). In the hyperemic state, the new method yielded less deviation in rMBF (3.890 +/- 1.250 mL/min/g, CV = 32.1 %) than those with the traditional method (3.962 +/- 1.762 mL/min/g, CV = 44.4%) (P <0.05). This method yielded significantly higher reproducibility of rMBF (r = 0.806, n = 576) than the original method (r = 0.756, n = 576) (P < 0.05). Our new method yielded a better correlation in the repeated measurement values of rMBF and less variability among the regions in the myocardium than with the original theory of the O-15-water technique. The simulation study demonstrated fewer effects of error in the PTF or Va on the MBF value with the new method. Conclusion: We have developed a technique for an automated, simplified, and stable algorithm to quantify rMBF. This software is considered to be practical for clinical use in myocardial PET studies using O-15-water with a high reproducibility and a short processing time.
  • S Kuroda, T Shiga, T Ishikawa, K Houkin, T Narita, C Katoh, N Tamaki, Y Iwasaki
    JOURNAL OF NUCLEAR MEDICINE 45 (6) 943 - 949 0161-5505 2004/06 [Refereed][Not invited]
     
    Recent studies have clarified that hemodynamically compromised patients are at high risk for subsequent stroke. The acetazolamide test is widely used to detect the patients with hemodynamic compromise due to occlusive carotid artery disease. Previous studies have suggested that patients with impaired reactivity to acetazolamide had an increased oxygen extraction fraction (OEF) on PET. However, the underlying pathophysiology has not been defined in patients with reduced blood flow and preserved reactivity to acetazolamide due to carotid occlusive diseases regardless of a normal appearance on MRI. This study aimed to clarify hemodynamic and metabolic parameters in such patients, using 150 gas and C-11-flumazenil (FMZ) PET. Methods: Our study included 15 patients who had reduced cerebral blood flow (CBF) and preserved cerebrovascular reactivity (CVR) to acetazolamide in the ipsilateral middle cerebral artery territory due to occlusive carotid diseases on N-isopropyl-p-I-123-iodoamphetamine (I-123-IMp) SPECT. We determined the CBF, cerebral metabolic rate for oxygen (CMRo(2)), cerebral blood volume (CBV), and OEF using 150 gas PET. The binding potential for C-11-FMZ was also measured in 5 patients. All patients were medically treated and followed-up during a mean period of 2.7 y. Results: 150 gas PET scans revealed that the ipsilateral CBF and CMRo(2) were reduced to 80% +/- 11% (P < 0.0001) and 78% +/- 8% (P < 0.0001) of the contralateral side, respectively. However, there was no significant side-to-side difference in the CBV and OEF The ipsilateral binding potential for C-11-FMZ was also significantly reduced to 82% +/- 2% of the contralateral side (P < 0.05), being very similar to the asymmetry of the CBF and CMRo(2). No patients suffered further ischemic stroke in the ipsilateral hemisphere during the follow-up period. Conclusion: Our results strongly suggest that a reduced CBF and a normal CVR characterize oxygen hypometabolism probably due to ischemia-related neuronal loss-namely, incomplete infarction. Such an ischemic lesion is not hemodynamically compromised and is at very low risk for a subsequent ischemic stroke even if the patient is medically treated.
  • M Tsukamoto, C Katoh, T Shiga, T Kaji, Y Kuge, K Nakada, N Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 31 (6) 846 - 851 1619-7070 2004/06 [Refereed][Not invited]
     
    To simplify the acquisition protocol of carbon-11 labeled flumazenil (FMZ) positron emission tomography (PET) for distribution volume (DV) images, we attempted to obtain standardized uptake value (SUV) images compatible with DV images, and assessed the applicability of this method in patients with unilateral cerebrovascular diseases (CVD). [C-11]FMZ PET was performed in ten normal subjects. A DV image and ten sequential 5-min SUV images were generated for each subject. We investigated the correlation coefficient (r) and standard estimation of error (SEE) between the latter ten static images and the DV image using the pixel-by-pixel method, thereby determining the optimum acquisition phase. The same FMZ PET procedure was performed in 15 patients with unilateral CVD. Twenty regions of interest (ROIs) were positioned both in lesioned areas and in symmetrical regions. DV and SUV in the optimum phase for each ROI were calculated to compare the lesion-to-normal (L/N) ratio of DV and that of SUV. The highest r and a low SEE (r=0.957, SEE=633) were observed from 30 to 35 min after tracer administration in the study of normal subjects. A high r (0.945) and a low SEE (0.0438) between the DV L/N ratio and the SUV L/N ratio were obtained in the study of patients. Our study suggests that SUV images acquired from 30 to 35 min after FMZ administration are a suitable alternative to DV images not only in normal subjects but also in patients with unilateral CVD. This simple method seems to be valuable for the identification of altered neuronal activity in patients with CVD.
  • S Kuroda, K Furukawa, T Shiga, S Ushikoshi, C Katoh, T Aoki, T Ishikawa, K Houkin, N Tamaki, Y Iwasaki
    NEUROSURGERY 54 (3) 585 - 591 0148-396X 2004/03 [Refereed][Not invited]
     
    OBJECTIVE: Retrograde drainage into the cortical veins results in poor outcome in patients with an intracranial dural arteriovenous fistula. However, the pathophysiological features of dural arteriovenous fistulae remain obscure. This study aimed to clarify hemodynamic and metabolic conditions in these patients using positron emission tomography. METHODS: This study included eight patients with an intracranial dural arteriovenous fistula. All patients had cortical venous reflux, as demonstrated by angiography. Regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), regional cerebral metabolic rate for oxygen, and regional oxygen extraction fraction (rOEF) were measured before and after surgical or endovascular treatment using positron emission tomography. RESULTS: Pretreatment positron emission tomographic studies revealed that all patients had abnormal hemodynamic and metabolic parameters in the area that was drained by the involved cortical veins. A severe increase in rCBV was noted in seven of the eight patients. A significant decrease in rCBF also was observed in all eight patients. A negative correlation was observed between rCBF and rCBV. Three patients had an elevated rOEF. Oxygen metabolism was impaired in seven patients. All patients underwent successful treatment. Follow-up studies demonstrated significant improvements in rCBF, rCBV, and regional cerebral metabolic rate for oxygen. The improvement in regional cerebral metabolic rate for oxygen varied among the patients. Normalization of rOEF also was confirmed in three patients who had increased rOEF before the treatment. CONCLUSION: The present results suggest that hemodynamic and metabolic characteristics vary widely among patients with cortical venous reflux. It is essential to precisely evaluate hemodynamic and metabolic conditions to predict their outcomes and therapeutic effects.
  • S. Kondo, S. Hirano, Y. Ambo, E. Tanaka, T. Kubota, H. Katoh
    British Journal of Surgery 91 (2) 248 - 251 0007-1323 2004/02 [Refereed][Not invited]
     
    Background: Portal vein and hepatic artery resection and reconstruction may be required in radical surgery for biliary cancer. Microvascular reconstruction requires special equipment and training, and may be difficult to accomplish when the arterial stump is small, when there are multiple vessels or when the stump lies deep within the wound. This study examined the feasibility and safety of arterioportal shunting as an alternative to arterial reconstruction. Methods: Over 30 months, ten patients with biliary cancer (six bile duct and four gallbladder carcinomas) underwent radical surgery with en bloc resection of the hepatic artery and end-to-side arterioportal reconstruction between the common hepatic or gastroduodenal artery and the portal trunk. Results: No patient died. Complications included bile leakage in two patients and liver abscess in one. Routine angiography performed 1 month after surgery revealed shunt occlusion in three patients. Once the existence of hepatopetal arterial collaterals had been confirmed in the remaining patients, the shunt was occluded by coil embolization. Conclusion: Arterioportal shunting appears to be a safe alternative to microvascular reconstruction after hepatic artery resection. However, the safety of the procedure and its potential to increase the cure rate require further assessment in a larger series with a longer follow-up.
  • C Katoh, K Morita, K Nakada, N Tamaki
    QUANTITATION IN BIOMEDICAL IMAGING WITH PET AND MRI (1265) 269 - 274 0531-5131 2004 [Refereed][Not invited]
     
    We have designed a new practical algorithm, which allows stable, rapid and automated quantification of regional MBF using O-15-water with PET. Methods: Thirty-six volunteers were employed in the static O-15-CO and dynamic O-15-water PET studies. To evaluate the reproducibility of the estimates, a repeat O-15-water scan was carried out. This algorithm includes a procedure for positioning a three-dimensional region of interest (ROI) of the whole myocardium and dividing it into 16 segments. Subsequently, the uniform input function was calculated using time-activity curves in the whole myocardial ROI and in the left ventricular ROI. The uniform input function allowed a simple and robust algorithm to estimate regional MBF. Estimates were compared with those by an original method. A simulation study was carried out to compare the effects of errors in PTF or Va on the MBF using the two methods. Results: The average analyzing time to define whole and 16 regional myocardial ROIs was less than 5 min. The new method yielded less deviated regional MBF than those with the traditional method. This method yielded significantly higher reproducibility of regional MBF than the original method. Our new method yielded a better correlation in the repeated measurement values of regional MBF and less variability among the regions in the myocardium than with an original theory of O-15-water technique. The simulation study demonstrated less effects of error in PTF or Va on the MBF value with the new method. Conclusions: We have developed a technique for an automated, simplified and stable algorithm to quantify regional MBF. This software is considered to be practical for clinical use in a myocardial PET study using O-15-water with high reproducibility and short processing time. (C) 2004 Published by Elsevier B.V.
  • K Noriyasu, T Tsukamoto, K Morita, H Kageyama, M Mabuchi, C Katoh, Y Kuge, A Kitabatake, N Tamaki
    PET AND MOLECULAR IMAGING: STATE OF THE ART AND FUTURE PERSPECTIVES 1264 271 - 274 0531-5131 2004 [Refereed][Not invited]
     
    We performed PET with carbon-11 acetate in patients with LV dysfunction in order to assess alterations in myocardial metabolism in apparently well-perfused myocardium in patients with dilated cardiomyopathy (DCM) and myocardial infarction (MI). We studied 15 patients with DCM 4and 16 patients with MI. The clearance rate constant for carbon-11 acetate derived from monoexponential fitting (Kmono) was measured as a marker of myocardial oxidative metabolism. We also performed PET in 10 normal subjects as control. Kmono was significantly lower in patients with DCM than in the control subjects (0.049 +/- 0.008 vs. 0.060 +/- 0.010 /min; P < 0.01). In contrast, Kmono in the remote areas in patients with MI was preserved (0.061 +/- 0.013), while Kmono in the infarcted areas (0.036 +/- 0.010) was significantly lower than that in the controls (P < 0.001). These data suggest that myocardial oxidative metabolism is preserved in remote area in patients with MI, despite LV remodeling, while it is decreased in patients with DCM. The reduction in oxidative metabolism may be one of the causes of LV dysfunction in patients with DCM but not in patients with MI. (C) 2004 Elsevier B.V. All rights reserved.
  • C Katoh, T Shiga, M Tsukamoto, T Kaji, N Tamaki
    PET AND MOLECULAR IMAGING: STATE OF THE ART AND FUTURE PERSPECTIVES 1264 181 - 185 0531-5131 2004 [Refereed][Not invited]
     
    cerebral metabolic rate of oxygen (CMRO2), a new method has been developed using 150-CO2, CO, O-2 and PET. Methods: Fifteen patients with carotid occlusion or stenosis were employed. One-minute inhalation of 150-CO and 3-min static scanning and blood sampling was performed to measure cerebral blood volume (CBV). With 2-min inhalation of 3 GBq 150-CO2, serial dynamic scanning and arterial blood sampling was performed for 6 min. With 15-min inhalation of 150-O-2, steady state O-2 image was scanned for 5 min, and arterial blood and plasma were sampled to measure oxygen extraction fraction (OEF) and CMRO2. In addition, to compare with conventional method, steady state CO2 image was scanned for 5 min with 15-min inhalation of 7.5 GBq 150-CO2 and arterial blood and plasma sampling. CBF and partition coefficient of water in the brain were estimated by non-linear curve fitting to the tissue time-activity curves. A new method was developed to measure OEF and CMRO2 using the known ratio of arterial H2O and O-2 concentration in O-2 steady state. The method does not require measuring the plasma counts. For each subject, about 2000 regions of interest (ROIs) were positioned, estimates calculated from a new method (newCBF, newOEF, newCMRO2) were correlated with those from conventional steady state method (ssCBF, ssOEF, ssCMRO2). Results: newCBF, newOEF and newCMRO2 presented significant correlation with those from steady state method, respectively (newCBF (ml/min/100 g)=1.07 ssCBF (ml/min/100 g)+3.17, r=0.934, p<0.001; newOEF=0.77 ssOEF-0.01, r=0.707, p<0.001; newCMRO2 (ml/min/100 g)=0.95 ssCMRO2 (ml/min/100 g)+0.04, r=0.856, p<0.001). The length of the scanning period was reduced 20 min and cut to 35 min for each patient to perform the new protocol study to measure CBF, OEF and CMRO2 without arterial plasma sampling. New method was able to reduce 4.5 GBq of 150-CO2 inhalation compared with the steady state method. Conclusion: We have developed a new method that permits quantitative measurement of CBF, OEF and CMRO2 with a short period acquisition time without arterial plasma sampling. The method also reduces radiation exposure of patients. This protocol may be of great value in clinical brain PET using 150 gas. (C) 2004 Elsevier B.V. All rights reserved.
  • T Tsukamoto, K Morita, K Noriyasu, C Katoh, H Kageyama, M Mabuchi, Y Kuge, K Nakada, H Okamoto, A Kitabatake, N Tamaki
    PET AND MOLECULAR IMAGING: STATE OF THE ART AND FUTURE PERSPECTIVES 1264 257 - 260 0531-5131 2004 [Refereed][Not invited]
     
    Objective: Myocardial blood flow reserve (MFR) measurement using PET has an important role to assess functional severity of coronary stenosis. However, discrepancy between anatomical severity of coronary stenosis and MFR is often observed. This study was conducted to assess influence of coronary stenosis severity and risk factors upon myocardial blood flow. Methods: 58 patients suspected of having coronary artery disease were enrolled. Myocardial blood flow (MBF) and MFR were measured using PET and oxygen-15-labeled water. MFR was compared with coronary stenosis severity by quantitative coronary angiography (QCA). In addition, a contribution of coronary risk factors to MFR was assessed using multivariate analysis. Results: In the regions with most severe stenosis, MFR correlated inversely with coronary stenosis severity. In multivariate analysis, coronary stenosis-severity was the only independent determinant of MFR. In the remote regions, however, MFR did not correlate with coronary stenosis severity. In multivariate analysis, smoking was the only independent predictor for MFR. Conclusion: MFR is determined by not only coronary stenosis severity but also coronary risk factors. Particularly, the influence of risk factor should be considered in the regions with mild coronary stenosis. (C) 2004 Published by Elsevier B.V.
  • T Shiga, K Ikoma, M Tsukamoto, C Katoh, T Matusyama, Y Kuge, K Nakada, S Terae, Y Mano, N Tamaki
    PET AND MOLECULAR IMAGING: STATE OF THE ART AND FUTURE PERSPECTIVES 1264 177 - 180 0531-5131 2004 [Refereed][Not invited]
     
    Objective: Traumatic brain injury causes cognitive disturbances in many cases. Some patients have moderate-severe brain dysfunction despite slight or no abnormality in MRI. The purpose of this study is to investigate whether the loss of neuronal integrity exists in the patients with traumatic brain injury using C-11 flumazenil PET (FMZ-PET) without MRI abnormality. Method: This study included 11 patients with traumatic brain injury and posttraumatic cognitive disturbances. All of the studies were examined at least 6 months later after injury. The dynamic flumazenil PET was studied in all patients. The binding potential of flumazenil (BP) was calculated by reference method. Axial T1WI, T2WI and FLAIR images were obtained with 1.5-T scanner. Coronal images were added in some cases. The BP images were visually interpreted by at least two experienced nuclear physicians by consensus. The lesions were determined as positive if a definite localized area of decreased distribution with respect to the surrounding normal tissue was present except for physiological distribution. Results: All of the patients had normal T1, T2 and FLAIR MRI. Nine patients had memory impairment. The low uptakes of BP images were shown in seven patients (63%). The low uptakes of BP were shown in the medial temporal lobe, the lateral temporal lobe, the temporal base and the frontal lobe in five, one, one and two patients, respectively. There were no patients that had low uptake in the cerebellum. Six of the nine patients who had memory impairment showed low uptakes in BP in the temporal lobe. Conclusion: These results indicated that the loss of the neuronal integrity, which was not able to be detected with MRI, was one of the causes of the cognitive disturbances in patients with traumatic brain injury. (C) 2004 Published by Elsevier B.V.
  • K Morita, C Katoh, N Tamaki
    PET AND MOLECULAR IMAGING: STATE OF THE ART AND FUTURE PERSPECTIVES 1264 132 - 135 0531-5131 2004 [Refereed][Not invited]
     
    Endothelium is a key player in atherosclerosis. Evaluation of endothelial function is important for not only an advanced, but also early stage of atherosclerosis. Endothelial function is assessed by measurement of vasomotor response to pharmacological or mechanical stimulation using quantitative coronary angiography or Doppler flow wire at rest and during stimulation. On the other hand, positron emission tomography (PET) with N-13-ammonia or O-15-labelled water provides quantitative values of myocardial blood flow (MBF). Therefore, PET study at rest and during stress enables quantification of coronary endothelial function without invasive procedures. Since coronary risk factors may alter endothelial function, quantification of endothelial function by PET plays an important role in assessing early atherosclerotic change, pathophysiology of cardiovascular disease and effects of medical or interventional treatments in patients with coronary risk factors. (C) 2004 Elsevier B.V. All rights reserved.
  • N Kubo, SJ Zhao, A Kinda, N Motomura, C Katoh, Y Kuge, N Tamaki
    PET AND MOLECULAR IMAGING: STATE OF THE ART AND FUTURE PERSPECTIVES 1264 275 - 279 0531-5131 2004 [Not refereed][Not invited]
     
    We have developed a pinhole collimator for small animal imaging using dual-isotopes, such as gamma and positron emitters. A lead cylinder containing a pinhole was placed around the subject (a small animal). The cylinder was equipped with a non-collimator gamma camera, and dual-isotope (99(m)Tc-MIBI and F-18-FDG) SPECT was performed on a Wistar King Aptekman/hok (WKAH) rat. System planar sensitivity and Full-Width at Half-Maximum (FWHM) were measured for each radionuclide. System planar sensitivities for Tc-99m and F-18 SPECT were 2 and 7 cps/MBq, respectively. FWHMs for Tc-99m and F-18 SPECT were 2.0 +/- 0.5 and 2.7 +/- 0.5 mm, respectively. The collimator is relatively light (23 kg), and thus SPECT projection data could be acquired by rotating the gamma camera while the object remained stationary. The pinhole collimator can be used with a conventional rotating gamma camera. The present study demonstrated that it is possible to image organs in vivo in sufficient detail using the newly developed pinhole collimator. Further refinements to the experimental procedure may provide simultaneous high-resolution imaging of small animals using positron and gamma emitters with this collimator. (C) 2004 Elsevier B.V. All rights reserved.
  • S. Kondo, H. Katoh, S. Hirano, Y. Ambo, E. Tanaka, S. Okushiba
    British Journal of Surgery 90 (6) 694 - 697 0007-1323 2003/06/01 [Refereed][Not invited]
     
    Background: Hepatobiliary cancer invading the hilar bile duct often involves the portal bifurcation. Portal vein resection and reconstruction is usually performed after completion of the hepatectomy. This retrospective study assessed the safety and usefulness of portal vein reconstruction prior to hepatic dissection in right hepatectomy and caudate lobectomy plus biliary reconstruction, one of the common procedures for radical resection. Methods: Clinical characteristics and perioperative results were compared in patients who underwent right hepatectomy and caudate lobectomy plus biliary reconstruction with (ten patients) and without (11 patients) portal reconstruction from September 1998 to March 2002. Results: All ten portal vein reconstructions were completed successfully before hepatic dissection the portal cross-clamp time ranged from 15 to 41 (median 22) min. Blood loss, blood transfusion during the operation, postoperative liver function, morbidity and length of hospital stay were similar in the two groups. No patient suffered postoperative hepatic failure or death. Conclusion: This study demonstrates that portal vein reconstruction does not increase the morbidity or mortality associated with right hepatectomy and caudate lobectomy with biliary reconstruction. This approach facilitates portal vein reconstruction for no-touch resection of hepatobiliary cancer invading the hilar bile duct.
  • K Yoshinaga, C Katoh, K Noriyasu, Y Iwado, H Furuyama, Y Ito, Y Kuge, T Kohya, A Kitabatake, N Tamaki
    JOURNAL OF NUCLEAR CARDIOLOGY 10 (3) 275 - 283 1071-3581 2003/05 [Refereed][Not invited]
     
    Background. Myocardial perfusion single photon emission computed tomography (SPECT) occasionally fails to detect coronary stenosis in patients with coronary artery disease (CAD). We evaluated coronary flow reserve (CFR) using oxygen 15-labeled water in areas with and without ischemia on technetium 99m tetrofosmin stress perfusion SPECT in patients with angiographically documented CAD. Methods and Results. Twenty-seven patients with CAD and eleven age-matched normal subjects were studied. Baseline myocardial blood flow (MBF),and MBF during hyperemia induced by intravenous adenosine triphosphate infusion (0.16 mg (.) kg(-1) (.) min(-1)) were determined with the use of O-15-labeled water positron emission tomography, and the CFR was calculated. Tc-99m tetrofosmin stress/rest SPECT was performed for comparison. On the basis of the results of coronary angiography and SPECT, coronary segments were divided into 3 types: segments with coronary stenosis and a perfusion abnormality on stress SPECT imaging (group A, n = 16), segments with coronary stenosis without a perfusion abnormality (group B, n = 42), and remote segments with no coronary stenosis or perftision abnormality (group C, n 18). Baseline MBF values were similar among the 3 groups. CFR in group A was lower (1.82 +/- 0.54) than in group B (2.22 +/- 0.87, P < .05), in group C (2.92 +/- 1.21, P < .01), and in normal segments (3.86 +/- 1.24, P < .001). CFR in group B was lower than in group C (P < .02) and in normal segments (P < .001). CFR in group C was lower than in normal segments (P < .02). Conclusions. Areas with a perfusion abnormality on stress SPECT had reduced CFR. In the areas without a perfusion abnormality and with coronary stenosis, lowering of CFR was intermediate between the areas with a perfusion abnormality and remote segments. Moreover, CFR was slightly, but significantly, lower in remote segments in patients with CAD compared with normal segments.
  • K Kudo, S Terae, C Katoh, M Oka, T Shiga, N Tamaki, K Miyasaka
    AMERICAN JOURNAL OF NEURORADIOLOGY 24 (3) 419 - 426 0195-6108 2003/03 [Refereed][Not invited]
     
    BACKGROUND AND PURPOSE: Blood vessels are usually conspicuous on dynamic CT perfusion images. The presence of large vessels may lead to overestimation of the quantitative value of cerebral blood flow (CBF). We evaluated the efficacy of the vascular-pixel elimination (VPE) method in quantitative CT perfusion imaging, in comparison with positron emission tomography (PET). METHODS: Five healthy volunteers underwent CT perfusion and PET studies. A four-channel multi-detector row CT scanner was used. Dynamic cine scanning was performed after bolus injection of an intravenous contrast agent. CT-CBF was calculated by the central volume principle and deconvolution method. PET was performed after infusion of O-15-labeled water. PET-CBF was calculated by using a nonlinear least squares method. Average CBF values of the whole section, gray matter, and white matter with both CT and PET were compared after image registration. The comparison was performed with and without VPE. In the VPE method, the vascular pixels were defined by the cerebral blood volume value of the pixel. The threshold of VPE was changed from 5 to 20 mL/100 g. Pixel-by-pixel correlation between CT-CBF and PET-CBF and linear regression analysis were also performed. RESULTS: Without VPE, CT-CBF was overestimated in all subjects. As the VPE threshold decreased, CT-CBF decreased and the correlation coefficient increased. The best correlation was observed at a VPE threshold of 8 mL/100 g in four of the five subjects. Average CT-CBF values, without VPE, of the whole section, gray matter, and white matter were 59.01, 66.73, and 42.53 mL/100 g/min, respectively. With VPE (threshold, 8 mL/100 g), average CT-CBF values of the whole section, gray matter, and white matter were 45.56, 52.75, and 30.38, respectively. The corresponding PET-CBF values were 46.86, 50.89, and 38.20 mL/100 g/min, respectively. CONCLUSION: Vascular pixels should be excluded from the calculation of CT-CBF to avoid overestimation of the CBF values. If vascular pixels are excluded, CBF calculation with CT perfusion imaging is considerably accurate.
  • Y Ito, C Katoh, K Noriyasu, Y Kuge, H Furuyama, K Morita, T Kohya, A Kitabatake, N Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 30 (2) 281 - 287 1619-7070 2003/02 [Refereed][Not invited]
     
    We developed a noninvasive method to quantitatively estimate the myocardial blood flow (MBF) index and flow reserve (MFR) using dynamic and static data obtained with technetium-99m sestamibi, and compared the results with MBF and MFR measured by oxygen-15-labeled water ([O-15]H2O) PET. Twenty patients with coronary artery disease (CAD) and nine normal subjects underwent both Tc-99m-sestamibi and PET studies within 2 weeks. From the anterior view, dynamic data were acquired for 2 min immediately after the injection of Tc-99m-sestamibi, and planar static images were also obtained after 5 min at rest and during ATP stress (0.16 mg kg(-1) min(-1) for 5 min) on another day. The area under the time-activity curve on the aortic arch (Aorta ACU), myocardial weight with the SPET image (M), and the myocardial count on the planar image for 1 min (C-m) were obtained. The MBF index (MBFI) was calculated as follows: MBFI=C-m/Aorta ACUx100/M. MFR was measured by dividing the MBFI at ATP stress by MBFI at rest. The MBFI measured by Tc-99m-sestamibi was significantly correlated with MBF obtained using [O-15]H2O PET (MBFI=13.174+11.732xMBF, r=0.821, P<0.001). Furthermore, MFR measured by Tc-99m-sestamibi was well correlated with that obtained using [O-15]H2O PET, with some underestimation (r=0.845, P<0.001). MFR using Tc-99m-sestamibi in patients with CAD was significantly lower than that in normal subjects (CAD: 1.484+/-0.256 vs normal: 2.127+/-0.308, P<0.001). These data suggest that the MBFI and MFR can be measured with Tc-99m-sestamibi. This may be useful for the quantitative assessment of CAD, especially in those patients with diffuse coronary disease.
  • H Furuyama, Y Odagawa, C Katoh, Y Iwado, Y Ito, K Noriyasu, M Mabuchi, K Yoshinaga, Y Kuge, K Kobayashi, N Tamaki
    JOURNAL OF PEDIATRICS 142 (2) 149 - 154 0022-3476 2003/02 [Refereed][Not invited]
     
    Objectives Coronary arterial lesions after Kawasaki disease (KD) may cause coronary endothelial dysfunction as the result of intimal hypertrophy. Our purpose was to assess myocardial flow reserve (MFR) and endothelial function in various myocardial regions after KD by using positron emission tomography. Study design Twenty-seven patients, 17.2 +/- 3.2 years of age, who had KD at 1.9 +/- 1.4 years, and 12 normal healthy subjects, 26.5 +/- 3.4 years of age, were evaluated by means of myocardial blood flow (MBF) with O-15-water positron emission tomography. MFR was estimated by MBF changes under adenosine triphosphate infusion and endothelial function by MBF changes under cold pressor testing. The left ventricle was divided into three coronary territories. Ten stenotic regions, 20 aneurysmal regions, 30 regressed aneurysmal regions, and 21 regions without coronary arterial lesions were compared with 36 control regions of the normal volunteers. Results MBF at rest was similar in each region. Hyperemic blood flow and MFR in each region after KD was significantly lower than those in the regions of normal volunteers. MBF during cold pressor testing was significantly reduced in each region after KD, as compared with no change in the control regions., Conclusions Our study indicates impaired MFR and endothelial function regardless of coronary artery status after KD.
  • T Kato, E Tsukamoto, Y Kuge, T Takei, T Shiga, N Shinohara, C Katoh, K Nakada, N Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 29 (11) 1492 - 1495 1619-7070 2002/11 [Refereed][Not invited]
     
    Carbon-11 acetate positron emission tomography (PET) has been reported to be of clinical value for the diagnosis of prostate cancer. However, no detailed analysis has yet been carried out on the physiological accumulation of [C-11]acetate in the prostate. The purpose of this study was to elucidate the physiological accumulation of [C-11]acetate in the prostate using dynamic PET. The study included 30 subjects without prostate cancer [21 with normal prostate and nine with benign prostatic hyperplasia (BPH)] and six patients with prostate cancer. A dynamic PET study was performed for 20 min after intravenous administration of 555 MBq of [C-11]acetate. The standardised uptake value (SUV) at 16-20 min post tracer administration and the early-to-late-activity ratio of the SUV (E/L ratio), which was determined by dividing the SUV6-10 min by the SUV16-20min, were calculated to evaluate the accumulation of [C-11]acetate. The prostate was clearly visualised and distinguished from adjacent organs in PET images in most of the cases. The SUV of the prostate (2.6+/-0.8) was significantly higher than that of the rectum (1.7+/-0.4) or bone marrow (1.3+/-0.3) (P<0.0001 in each case). The SUV of the normal prostate of subjects aged <50 years (3.4+/-0.7) was significantly higher than both the SUV for the normal prostate of subjects aged greater than or equal to50 years (2.3+/-0.7) and that of subjects with BPH (2.1+/-0.6) (P<0.01 in each case). The primary prostate cancer in six cases was visualised by [C-11]acetate PET. However, the difference in the SUV between subjects aged greater than or equal to50 with normal prostate or with BPH and the patients with prostate cancer (1.9+/-0.6) was not statistically significant. There was also no significant difference in the E/L ratio between subjects aged greater than or equal to50 with normal prostate (0.98+/-0.04) or BPH (0.96+/-0.08) and patients with prostate cancer (1.02+/-0.12). In conclusion, a normal prostate exhibits age-related physiological accumulation of [C-11]acetate. Careful interpretation of [C-11]acetate PET images of prostate cancer is necessary because the SUV and the E/L ratio for the normal prostate and for BPH overlap significantly with those for prostate cancer.
  • 中駄 邦博, 竹井 俊樹, 加藤 千恵次, 山本 文泰, 塚本 正仁, 青山 英史, 久下 祐司, 塚本 江利子, 玉木 長良, 鈴木 幸太郎, 表 英彦
    核医学 (一社)日本核医学会 39 (3) 398 - 398 0022-7854 2002/09
  • 頸動脈閉塞性疾患におけるacetazolamide反応性とPETパラメータとの関連について 定量的解析
    黒田 敏, 宝金 清博, 岩崎 喜信, 志賀 哲, 加藤 千恵次, 玉木 長良
    脳循環代謝 (一社)日本脳循環代謝学会 14 (3) 213 - 214 0915-9401 2002/09
  • M Mabuchi, N Kubo, K Morita, K Noriyasu, Y Itoh, C Katoh, Y Kuge, N Tamaki
    NUCLEAR MEDICINE COMMUNICATIONS 23 (9) 879 - 885 0143-3636 2002/09 [Refereed][Not invited]
     
    Single photon emission computed tomography (SPECT) using ultra-high energy collimators permits wide clinical application of 18 F-fluorodeoxyglucose (FDG) imaging without the use of expensive positron emission tomography (PET) cameras. This study was designed to evaluate the value of FDG SPECT using ultra-high energy collimators in assessing myocardial viability compared with FDG PET on a regional basis. We prospectively studied 33 patients with ischaemic heart disease. The patients were injected with 555 MBq of FDG under a hyperinsulinaemic glucose clamp, and FDG PET was performed 40 min later. FDG SPECT using ultra-high energy collimators was performed immediately after FDG PET. The images of the left ventricular myocardium were divided into nine segments and the regional defect score was assessed visually using a four-point scale (0 = normal to 3 = defect). Regional FDG uptake (%uptake) was quantitatively analysed using polar maps. In 297 segments of all the 33 patients, agreement between the defect scores based on FDG SPECT images and those based on FDG PET images was 70%, and agreement within one rank was 96% (kappa value= 0.52). The %uptake based on FDG SPECT images significantly correlated with that based on FDG PET images (r = 0.77, P < 0.01). However, the defect scores in the inferior wall based on FDG SPECT images were higher (1.41+/-1.14) than those based on FDG PET images (1.06+/-1.12, P<0.01). When the viable region is defined as %uptake greater than or equal to50% in FDG PET studies, the optimal cut-off level of %uptake based on FDG SPECT images was 60% in the anterior wall, apex, septum and lateral wall (accuracies, 97%, 93%, 96% and 99%, respectively), and 45% in the inferior wall (accuracy, 99%). It is concluded that FDG SPECT using ultra-high energy collimators can be used for the assessment of myocardial viability as accurately as FDG PET. However, a slight difference was observed in the defect scores mainly due to attenuation in the inferior wall. Therefore, a slightly different cut-off level for assessing myocardial viability should be applied to the inferior wall when using FDG SPECT. ((C) 2002 Lippincott Williams Wilkins).
  • Y Iwado, K Yoshinaga, H Furuyama, Y Ito, K Noriyasu, C Katoh, Y Kuge, E Tsukamoto, N Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 29 (8) 984 - 990 1619-7070 2002/08 [Refereed][Not invited]
     
    Chronic cigarette smoking alters coronary vascular endothelial response. To determine whether altered response also occurs in young individuals without manifest coronary disease we quantified coronary blood flow at rest, following adenosine vasodilator stress and during the cold pressor test in healthy young smokers. Myocardial blood flow (MBF) was quantified by oxygen-15 labelled water positron emission tomography in 30 healthy men aged from 20 to 35 years (18 smokers and 12 non-smokers, aged 27.4 +/- 4.4 vs 26.3 +/- 3.3). The smokers had been smoking cigarettes for 9.4 +/- 4.9 pack-years, MBF was measured at rest, during intravenous adenosine triphosphate (ATP: 0.16 mg kg(-1) min(-1)) infusion (hyperaemic response), and during cold pressor test (CPT) (endothelial vasodilator response). Rest MBF and hyperaemic MBF did not differ significantly between the smokers and the non-smokers (rest: 0.86 +/- 0.11 vs 0.92 +/- 0.14 and ATP: 3.20 +/- 1.12 vs 3.69 +/- 0.76 ml g(-1) min(-1); P=NS). Coronary flow reserve was similar between the two groups (smokers: 3.78 +/- 1.83; non-smokers: 4.03 +/- 0.68; P=NS). Although CPT induced a similar increase in rate-pressure product (RPP) in the smokers and the non-smokers (10,430 +/- 1,820 vs 9,236 +/- 1,356 beats min(-1) mmHg(-1)), CPT MBF corrected by RPP was significantly decreased in the smokers (0.65 +/- 0.12 ml g(-1) min(-1)) compared with the non-smokers (0.87 +/- 0.12 ml g(-1) min(-1)) (P<0.05). In addition, the ratio of CPT MBF to resting MBF was inversely correlated with pack-years (r=-0.57, P=0.014). Endothelium-dependent coronary artery vasodilator function is impaired in apparently healthy young smokers.
  • T Kato, E Tsukamoto, Y Kuge, C Katoh, T Nambu, A Nobuta, S Kondo, M Asaka, N Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 29 (8) 1047 - 1054 1619-7070 2002/08 [Refereed][Not invited]
     
    In extrahepatic bile duct cancer, preoperative evaluation is important because only surgical excision of all detectable tumours is associated with improvement in 5-year survival. However, morphological imaging techniques, including computed tomography (CT), are still insufficient for accurate staging. The purpose of this study was to assess the additional value, in relation to CT, of 2-[F-18]fluoro-2-deoxy-D-glucose positron emission tomography (F-18-FDG PET) for the evaluation of extrahepatic bile duct cancer. Thirty patients with extrahepatic bile duct cancer underwent both F-18-FDG PET and CT for initial staging. The results of the two modalities for evaluation of primary tumours and regional lymph nodes were compared with the final diagnoses based on pathological or clinical findings. The primary tumours were interpreted as malignant on the basis of CT in 24 (80%) of the patients, while F-18-FDG PET revealed increased F-18-FDG uptake in 18 (60%) of them. On the other hand, F-18-FDG PET showed focal accumulation of F-18-FDG in the bile duct in three of the six patients with equivocal findings on CT. The sensitivity, specificity and accuracy of CT for regional lymph node metastases were 54%, 59% and 57%, while those of F-18-FDG PET were 38%, 100% and 73%, respectively. The specificity of F-18-FDG PET for regional lymph node metastases was significantly higher than that of CT (P<0.01). Of 14 patients with N1 or N2 disease diagnosed by CT, only seven (50%) had a final diagnosis of regional lymph node metastasis. In these 14 patients, F-18-FDG PET accurately evaluated the N component of the disease in 12 patients (86%). In conclusion, in the initial staging of patients with extrahepatic bile duct cancer, F-18-FDG PET offers additional value in relation to CT in evaluating both the primary tumour and regional lymph nodes.
  • N Kubo, M Mabuchi, C Katoh, H Arai, K Morita, E Tsukamoto, Y Morita, N Tamaki
    NUCLEAR MEDICINE COMMUNICATIONS 23 (7) 639 - 643 0143-3636 2002/07 [Refereed][Not invited]
     
    A scintillator-photodiode camera is able to acquire single photon emission computed tomography (SPECT) images by using a rotating chair system. We validated the left ventricular (LV) parameters of this camera system utilizing a dynamic myocardial phantom. Gated myocardial SPECT of a dynamic myocardial phantom (Hokkaido University type; end diastolic volume (EDV), 143 ml; end systolic volume (ESV), 107 ml; ejection fraction (EF), 25%) was performed with this scintillation camera. LV parameters were calculated using pre-installed software (Mirage Myocardial Perfusion SPECT) (study 1) and the other software (QGS; Cedars-Sinai) (study 2). For comparison, SPECT from a traditional Anger camera were processed by the QGS software (study 3). The estimated volumes were similar among the three studies (EDV, 110+/-8 ml in study 1, 112+/-2 ml in study 2 and 111+/-1 ml in study 3; ESV, 86 8 ml in study 1, 93+/-4 ml in study 2 and 91+/-2 ml in study 3). The estimated EFs were 23+/-3%, 17+/-2%, and 18+/-1%, respectively. The calculated volume within each study was underestimated by approximately the same degree. However, each estimated EF value for each study was close to the actual value. The estimated LV function using the scintillator-photodiode camera system may be considered as a suitable alternative to the traditional Anger camera system. ((C) 2002 Lippincott Williams Wilkins).
  • K Yoshinaga, C Katoh, K Noriyasu, S Yamada, Y Ito, Y Kuge, Y Kawai, T Kohya, A Kitabatake, N Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 29 (7) 882 - 890 1619-7070 2002/07 [Refereed][Not invited]
     
    The detection of viable myocardium is important for the prediction of functional recovery after revascularisation. However, a fixed perfusion defect often includes viable myocardium, and perfusion imaging then underestimates myocardial viability. We previously reported that low-dose dobutamine stress gated single-photon emission tomography (SPET) provides similar findings to dobutamine stress echocardiography in the assessment of myocardial viability. The present study investigated whether low-dose dobutamine stress gated SPET is of additional value as compared with stress-rest technetium-99m tetrofosmin SPET for the detection of myocardial viability. Standard stress-rest perfusion SPET, low-dose dobutamine stress gated SPET and fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) were studied in 23 patients (mean age 67+/-7.6 years) with previous myocardial infarction. Twenty-one of them were successfully studied with each technique. FDG PET viability (FDG uptake greater than or equal to50%) was employed as the gold standard. One-day stress-rest Tc-99m-tetrofosmin myocardial SPET was performed. After the resting study, gated SPET was acquired following infusion of 7.5 mug kg(-1) min(-1) of dobutamine. Left ventricular wall motion in 16 segments was assessed by cine mode display using a four-point scale. Myocardial viability was considered present when there was improvement by one point. Of a total of 336 segments analysed, 53 had persistent defects on stress-rest perfusion SPET. FDG viability was seen in 16 of 17 dobutamine-responsive segments, but in only 11 of 36 dobutamine non-responsive segments (P<0.01). Thus, in the segments with persistent defects, viability findings on low-dose dobutamine stress gated SPET were concordant with those on FDG PET in 77% of segments (kappa value =0.55). For the detection of FDG-viable myocardium, the combination of stress-rest perfusion SPET and low-dose dobutamine stress gated SPET achieved a better sensitivity than stress-rest perfusion SPET alone (35/46, 76% vs 19/46, 41.3%, P<0.001), with a similar specificity (25/29, 86% vs 26/29, 90%, P=NS). We conclude that in the identification of viable myocardium, low-dose dobutamine stress gated SPET may provide additional information missed on a routine stress-rest perfusion scan. Dobutamine stress gated SPET may provide new insights into myocardial viability on the basis of ischaemia and contractile reserve.
  • N Kubo, M Mabuchi, C Katoh, K Morita, E Tsukamoto, Y Morita, N Tamaki
    NUCLEAR MEDICINE COMMUNICATIONS 23 (6) 529 - 536 0143-3636 2002/06 [Refereed][Not invited]
     
    We have investigated the accuracy and reproducibility of left ventricular (LV) functions using quantitative, gated, single photon emission computed tomography (SPECT) software dependent on critical frequencies of pre-reconstruction filters. This study incorporated dynamic myocardial phantoms (myocardial and cone shapes). Gated SPECT of 8-interval sets were pre-filtered with Butterworth filters (critical frequency varying between 0.16 and 1.16 cycles/cm, order 5) and with no filter. Phantoms were repositioned, and SPECT acquisitions were repeated. As the critical frequency increased, the estimated LV volume increased to reach a plateau at the level of the critical frequency, 0.54 cycles/cm. Conversely, the values of ejection fractions, wall motion and wall thickening with different filters which used critical frequency of greater than or equal to 0.39 cycles/cm remained unchanged. However, LV functions and volumes were underestimated when any pre-reconstruction filter was used. Standard deviations of LV functions after repeated measurements were unaffected by different filters with critical frequencies of greater than or equal to0.39 cycles/cm. Standard deviations of LV volume, ejection fraction, wall motion and wall thickening were <2.2 ml, <0.9%, <0.6 nun and <8.7%, respectively. Therefore, with the exception of low critical frequencies, LV functions and volumes were highly reproducible when these routine reconstruction filters were used. ((C) 2002 Lippincott Williams Wilkins).
  • H Furuyama, Y Odagawa, C Katoh, Y Iwado, K Yoshinaga, Y Ito, K Noriyasu, M Mabuchi, Y Kuge, K Kobayashi, N Tamaki
    CIRCULATION 105 (24) 2878 - 2884 0009-7322 2002/06 [Refereed][Not invited]
     
    Background-Coronary abnormalities after Kawasaki disease (KD) may be associated with endothelial dysfunction due to intimal hypertrophy. The purpose of this study was to evaluate myocardial flow reserve (MFR) and endothelial function in regressed aneurysmal regions after KD. Methods and Results-Subjects were 12 patients aged 16.0+/-2.6 years who suffered from KD at 1.7+/-1.5 years and 12 normal subjects aged 26.5+/-3.4 years. MFR and endothelial function were estimated, respectively, by changes in myocardial blood flow (MBF) during ATP infusion and by that during cold pressor test using O-15-water positron emission tomography. Data from 24 regressed aneurysmal regions were compared with those from the corresponding regions (n=36) in the control group. Although the MBF at rest in the regressed aneurysmal regions was similar to that in controls, the MBF at a hyperemic state induced by ATP infusion in the regressed aneurysmal regions was significantly lower than that in the control regions. Therefore, the MFR in regressed aneurysmal regions was significantly lower than that in controls (3.53+/-0.95 versus 4.60+/-1.14; P<0.05). MBF at rest and during the cold pressor test did not change in the control regions, but it was significantly reduced in regressed aneurysmal regions. The ratio of MBF during the cold pressor test to MBF at rest was significantly lower in regressed aneurysmal regions than in control regions (0.67+/-0.15 versus 1.00+/-0.15; P<0.05). Conclusions-MFR and endothelial function are often impaired in regressed aneurysmal regions after KD, and tomography enables the noninvasive evaluation of coronary function.
  • S Kohri, Y Hoshi, M Tamura, C Kato, Y Kuge, N Tamaki
    PHYSIOLOGICAL MEASUREMENT 23 (2) 301 - 312 0967-3334 2002/05 [Refereed][Not invited]
     
    Combining spatially- and time-resolved spectroscopies, we attempted to quantitatively evaluate the contribution ratio of the partial mean pathlength of cerebral tissue to the observed overall mean pathlength, in which haemoglobin concentrations were selectively changed by administration of acetazolamide. When acetazolamide was administered, the observed increases in oxygenated haemoglobin depended on the probe distance, which became progressively larger at distances of 2, 3 and 4 cm. Increases in oxygen saturation were detected at 3 and 4 cm spacing, but not at 2 cm. Assuming that the modified Lambert-Beer's law can exist in the inhomogeneous structure of the head, then, we could estimate the contribution ratio of the cerebral tissue to optical signals at the probe distances of 2, 3 and 4 cm as 33%, 55% and 69%, respectively. Using these values, we recalculated acetazolamide-induced concentration changes in oxygenated-haemoglobin in the cerebral tissue, which resulted in the same values at distances of 2, 3 and 4 cm as expected. Thus, our present method opened the door to the possibility of selectively obtaining optical signals attributed to cerebral tissue.
  • Tohru Shiga, Sinobu Matsuura, Chietsugu Katoh, Yuji Kuge, T. Koyanagi, Nagara Tamaki
    International Congress Series 1232 (C) 495 - 498 0531-5131 2002/04/01 [Refereed][Not invited]
     
    Purpose: It is broadly accepted that the brain control is crucial to maintain the urinary continence. However, the brain system concerned in urine storage remains unclear in human. The aim of this study was to identify the brain regions involved in urine storage in normal subjects. Materials: The study population consisted of 10 male normal volunteers with ages ranging from 27 to 41 years old. All of them were right handed. None of them had suffered from any psychiatric or neurological disorder. Methods: Brain perfusion PET was repeated with O-15 H2O injection under empty bladder and filled bladder following saline infusion with a catheter. In each condition, three scans were obtained for statistical analysis. The data were analyzed using Statistical Mapping Procedure. A corrected P-value under 0.0001 was considered as statistical significant. Results: During urine storage, a significantly activated area was found only in the central part of the midbrain. There is no significant increase in cerebral blood flow in the brain cortex. These data seem to be concordant with the animal experiments. Conclusion: Our PET data indicated that the central part of the midbrain was involved in the urine storage function in the human brain. © 2002, Elsevier B.V. All rights reserved.
  • もやもや病の脳循環代謝 SPECT/PETによる検討
    七戸 秀夫, 黒田 敏, 宝金 清博, 岩崎 喜信, 志賀 哲, 加藤 千恵次, 玉木 長良
    脳循環代謝 (一社)日本脳循環代謝学会 14 (1) 81 - 81 0915-9401 2002/03
  • T Shiga, N Kubo, A Takano, J Kobayashi, Y Takeda, F Nakamura, C Katoh, T Koyama, E Tsukamoto, N Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 29 (3) 342 - 345 1619-7070 2002/03 [Refereed][Not invited]
     
    Scatter correction (SC) using the triple energy, window method (TEW) has recently been applied for brain perfusion single-photon emission tomography (SPET). The aim of this study was to investigate the effect of scatter correction using TEW on N-isopropyl-p-[I-123]iodoamphetamine (I-123-IMP) SPET in normal subjects. The study population consisted of 15 right-handed normal subjects. SPET data were acquired from 20 min to 40 min after the injection of 167 MBq of IMP. using a triple-head gamma camera. Images were reconstructed c with and without SC. 3D TI-weighted magnetic resonance (MR) images were also obtained with a 1.5-Tesla scanner. First, IMP images with and without SC were co-registered to the 3D MRI. Second, the two co-registered IMP images were normalised using SPM96. A t statistic image for the contrast condition effect was constructed. We investigated areas using a voxel-level threshold of 0.001, with a corrected threshold of 0.05. Compared with results obtained without SC. the IMP distribution with SC was significantly decreased in the peripheral areas of the cerebellum, the cortex and the ventricle, and also in the lateral occipital cortex and the base of the temporal lobe. On the other hand, the IMP distribution with SC was significantly increased in the anterior and posterior cingulate cortex, the insular cortex and the medial part of the thalamus. It is concluded that difference,,, in the IMP distribution with and without SC exist not only in the peripheral areas of the cerebellum. the cortex and the ventricle but also in the occipital lobe, the base of the temporal lobe, the insular cortex, the medial part of the thalamus. and the anterior and posterior cingulate cortex, This needs to be recognised for adequate interpretation of IMP brain perfusion SPET after scatter correction.
  • 笹木 工, 山下 道明, 孫田 恵一, 寺江 聡, 工藤 與亮, 加藤 千恵次
    日本放射線技術学会雑誌 公益社団法人 日本放射線技術学会 58 (9) 1146 - 1146 2002
  • Keiichiro Yoshinaga, Chietsugu Katoh, Kazuyuki Noriyasu, Satoshi Yamada, Yoshinori Ito, Yuji Kuge, Yuko Kawai, Tetsuro Kohya, Akira Kitabatake, Nagara Tamaki
    European Journal of Nuclear Medicine 29 (7) 882 - 890 0340-6997 2002 [Refereed][Not invited]
     
    The detection of viable myocardium is important for the prediction of functional recovery after revascularisation. However, a fixed perfusion defect often includes viable myocardium, and perfusion imaging then underestimates myocardial viability. We previously reported that low-dose dobutamine stress gated single-photon emission tomography (SPET) provides similar findings to dobutamine stress echocardiography in the assessment of myocardial viability. The present study investigated whether low-dose dobutamine stress gated SPET is of additional value as compared with stress-rest technetium-99m tetrofosmin SPET for the detection of myocardial viability. Standard stress-rest perfusion SPET, low-dose dobutamine stress gated SPET and fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) were studied in 23 patients (mean age 67±7.6 years) with previous myocardial infarction. Twenty-one of them were successfully studied with each technique. FDG PET viability (FDG uptake ≥50%) was employed as the gold standard. One-day stress-rest 99mTc-tetrofosmin myocardial SPET was performed. After the resting study, gated SPET was acquired following infusion of 7.5 μg kg-1 min-1 of dobutamine. Left ventricular wall motion in 16 segments was assessed by cine mode display using a four-point scale. Myocardial viability was considered present when there was improvement by one point. Of a total of 336 segments analysed, 53 had persistent defects on stress-rest perfusion SPET. FDG viability was seen in 16 of 17 dobutamine-responsive segments, but in only 11 of 36 dobutamine non-responsive segments (P< 0.01). Thus, in the segments with persistent defects, viability findings on low-dose dobutamine stress gated SPET were concordant with those on FDG PET in 77% of segments (kappa value =0.55). For the detection of FDG-viable myocardium, the combination of stress-rest perfusion SPET and low-dose dobutamine stress gated SPET achieved a better sensitivity than stress-rest perfusion SPET alone (35/46, 76% vs 19/46, 41.3%, P< 0.001), with a similar specificity (25/29, 86% vs 26/29, 90%, P=NS). We conclude that in the identification of viable myocardium, low-dose dobutamine stress gated SPET may provide additional information missed on a routine stress-rest perfusion scan. Dobutamine stress gated SPET may provide new insights into myocardial viability on the basis of ischaemia and contractile reserve.
  • Takashi Kato, Eriko Tsukamoto, Yuji Kuge, Chietsugu Katoh, Toshikazu Nambu, Aichiro Nobuta, Satoshi Kondo, Masahiro Asaka, Nagara Tamaki
    European Journal of Nuclear Medicine 29 (8) 1047 - 1054 0340-6997 2002 [Refereed][Not invited]
     
    In extrahepatic bile duct cancer, preoperative evaluation is important because only surgical excision of all detectable tumours is associated with improvement in 5-year survival. However, morphological imaging techniques, including computed tomography (CT), are still insufficient for accurate staging. The purpose of this study was to assess the additional value, in relation to CT, of 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG PET) for the evaluation of extrahepatic bile duct cancer. Thirty patients with extrahepatic bile duct cancer underwent both 18F-FDG PET and CT for initial staging. The results of the two modalities for evaluation of primary tumours and regional lymph nodes were compared with the final diagnoses based on pathological or clinical findings. The primary tumours were interpreted as malignant on the basis of CT in 24 (80%) of the patients, while 18F-FDG PET revealed increased 18F-FDG uptake in 18 (60%) of them. On the other hand, 18F-FDG PET showed focal accumulation of 18F-FDG in the bile duct in three of the six patients with equivocal findings on CT. The sensitivity, specificity and accuracy of CT for regional lymph node metastases were 54%, 59% and 57%, while those of 18F-FDG PET were 38%, 100% and 73%, respectively. The specificity of 18F-FDG PET for regional lymph node metastases was significantly higher than that of CT (P< 0.01). Of 14 patients with N1 or N2 disease diagnosed by CT, only seven (50%) had a final diagnosis of regional lymph node metastasis. In these 14 patients, 18F-FDG PET accurately evaluated the N component of the disease in 12 patients (86%). In conclusion, in the initial staging of patients with extrahepatic bile duct cancer, 18F-FDG PET offers additional value in relation to CT in evaluating both the primary tumour and regional lymph nodes.
  • Yasuyoshi Iwado, Keiichiro Yoshinaga, Hideto Furuyama, Yoshinori Ito, Kazuyuki Noriyasu, Chietsugu Katoh, Yuji Kuge, Eriko Tsukamoto, Nagara Tamaki
    European Journal of Nuclear Medicine 29 (8) 984 - 990 0340-6997 2002 [Refereed][Not invited]
     
    Chronic cigarette smoking alters coronary vascular endothelial response. To determine whether altered response also occurs in young individuals without manifest coronary disease we quantified coronary blood flow at rest, following adenosine vasodilator stress and during the cold pressor test in healthy young smokers. Myocardial blood flow (MBF) was quantified by oxygen-15 labelled water positron emission tomography in 30 healthy men aged from 20 to 35 years (18 smokers and 12 non-smokers, aged 27.4±4.4 vs 26.3±3.3). The smokers had been smoking cigarettes for 9.4±4.9 pack-years. MBF was measured at rest, during intravenous adenosine triphosphate (ATP: 0.16 mg kg-1 min-1) infusion (hyperaemic response), and during cold pressor test (CPT) (endothelial vasodilator response). Rest MBF and hyperaemic MBF did not differ significantly between the smokers and the non-smokers (rest: 0.86±0.11 vs 0.92±0.14 and ATP: 3.20±1.12 vs 3.69±0.76 ml g-1 min-1 P=NS). Coronary flow reserve was similar between the two groups (smokers: 3.78±1.83 non-smokers: 4.03±0.68 P=NS). Although CPT induced a similar increase in rate-pressure product (RPP) in the smokers and the non-smokers (10,430±1,820 vs 9,236±1,356 beats min-1 mmHg-1), CPT MBF corrected by RPP was significantly decreased in the smokers (0.65±0.12 ml g-1 min-1) compared with the non-smokers (0.87±0.12 ml g-1 min-1) (P< 0.05). In addition, the ratio of CPT MBF to resting MBF was inversely correlated with pack-years (r=-0.57, P=0.014). Endothelium-dependent coronary artery vasodilator function is impaired in apparently healthy young smokers.
  • Tohru Shiga, Naoki Kubo, Akihiro Takano, Junko Kobayashi, Yoji Takeda, Fumihiro Nakamura, Chietsugu Katoh, Tsukasa Koyama, Eriko Tsukamoto, Nagara Tamaki
    European Journal of Nuclear Medicine 29 (3) 342 - 345 0340-6997 2002 [Refereed][Not invited]
     
    Scatter correction (SC) using the triple energy window method (TEW) has recently been applied for brain perfusion single-photon emission tomography (SPET). The aim of this study was to investigate the effect of scatter correction using TEW on N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) SPET in normal subjects. The study population consisted of 15 right-handed normal subjects. SPET data were acquired from 20 min to 40 min after the injection of 167 MBq of IMP, using a triple-head gamma camera. Images were reconstructed with and without SC. 3D T1-weighted magnetic resonance (MR) images were also obtained with a 1.5-Tesla scanner. First, IMP images with and without SC were co-registered to the 3D MRI. Second, the two co-registered IMP images were normalised using SPM96. A t statistic image for the contrast condition effect was constructed. We investigated areas using a voxel-level threshold of 0.001, with a corrected threshold of 0.05. Compared with results obtained without SC, the IMP distribution with SC was significantly decreased in the peripheral areas of the cerebellum, the cortex and the ventricle, and also in the lateral occipital cortex and the base of the temporal lobe. On the other hand, the IMP distribution with SC was significantly increased in the anterior and posterior cingulate cortex, the insular cortex and the medial part of the thalamus. It is concluded that differences in the IMP distribution with and without SC exist not only in the peripheral areas of the cerebellum, the cortex and the ventricle but also in the occipital lobe, the base of the temporal lobe, the insular cortex, the medial part of the thalamus, and the anterior and posterior cingulate cortex. This needs to be recognised for adequate interpretation of IMP brain perfusion SPET after scatter correction.
  • Takashi Kato, Eriko Tsukamoto, Yuji Kuge, Toshiki Takei, Tohru Shiga, Nobuo Shinohara, Chietsugu Katoh, Kunihiro Nakada, Nagara Tamaki
    European Journal of Nuclear Medicine 29 (11) 1492 - 1495 0340-6997 2002 [Refereed][Not invited]
     
    Carbon-11 acetate positron emission tomography (PET) has been reported to be of clinical value for the diagnosis of prostate cancer. However, no detailed analysis has yet been carried out on the physiological accumulation of [11C]acetate in the prostate. The purpose of this study was to elucidate the physiological accumulation of [11C]acetate in the prostate using dynamic PET. The study included 30 subjects without prostate cancer [21 with normal prostate and nine with benign prostatic hyperplasia (BPH)] and six patients with prostate cancer. A dynamic PET study was performed for 20 min after intravenous administration of 555 MBq of [11C]acetate. The standardised uptake value (SUV) at 16-20 min post tracer administration and the early-to-late-activity ratio of the SUV (E/L ratio), which was determined by dividing the SUV6-10 min by the SUV16-20min, were calculated to evaluate the accumulation of [11C]acetate. The prostate was clearly visualised and distinguished from adjacent organs in PET images in most of the cases. The SUV of the prostate (2.6±0.8) was significantly higher than that of the rectum (1.7±0.4) or bone marrow (1.3±0.3) (P< 0.0001 in each case). The SUV of the normal prostate of subjects aged < 50 years (3.4±0.7) was significantly higher than both the SUV for the normal prostate of subjects aged ≥50 years (2.3±0.7) and that of subjects with BPH (2.1±0.6) (P< 0.01 in each case). The primary prostate cancer in six cases was visualised by [11C]acetate PET. However, the difference in the SUV between subjects aged ≥50 with normal prostate or with BPH and the patients with prostate cancer (1.9±0.6) was not statistically significant. There was also no significant difference in the E/L ratio between subjects aged ≥50 with normal prostate (0.98±0.04) or BPH (0.96±0.08) and patients with prostate cancer (1.02±0.12). In conclusion, a normal prostate exhibits age-related physiological accumulation of [11C]acetate. Careful interpretation of [11C]acetate PET images of prostate cancer is necessary because the SUV and the E/L ratio for the normal prostate and for BPH overlap significantly with those for prostate cancer.
  • Noji T, Kondo S, Hirano S, Ambo Y, Tanaka E, Katoh C, Tsukamoto E, Tamaki N, Katoh H
    International journal of gastrointestinal cancer 32 (1) 43 - 46 1537-3649 2002 [Refereed][Not invited]
  • 脳主幹動脈閉塞性疾患における脳酸素代謝とacetazolamide反応性
    黒田 敏, 宝金 清博, 志賀 哲, 加藤 千恵次, 玉木 長良, 岩崎 喜信, 阿部 弘
    脳循環代謝 (一社)日本脳循環代謝学会 13 (4) 328 - 328 0915-9401 2001/12
  • 黒田 敏, 宝金 清博, 岩崎 喜信, 阿部 弘, 志賀 哲, 加藤 千恵次, 玉木 長良
    新潟医学会雑誌 新潟医学会 115 (11) 599 - 599 0029-0440 2001/11
  • N Tamaki, Y Kuge, C Katoh
    NUCLEAR MEDICINE COMMUNICATIONS 22 (8) 847 - 850 0143-3636 2001/08 [Refereed][Not invited]
  • 脳虚血 病態診断の進歩と限界 脳主幹動脈閉塞性疾患における脳酸素代謝とAcetazolamide反応性の関係について SPECT上のtype3はmisery perfusionを示唆するのか?
    黒田 敏, 宝金 清博, 志賀 哲, 加藤 千恵次, 玉木 長良, 岩崎 喜信, 阿部 弘
    The Mt. Fuji Workshop on CVD (株)にゅーろん社 19 41 - 44 0289-8438 2001/07 
    脳主幹動脈閉塞性疾患で,SPECTにてacetazolamide反応性を測定し,type 3と診断された症例を対象として比較検討した.PETパラメーターは,SPECTでtype 3と判定された各症例中で一様ではないことが判明した.即ち,rOEFが上昇している症例は14側中9側(64%),rCMRO2がほぼ正常域に保たれているのは6側,更に脳血管拡張が強く生じていることを示すrCBVの増加を伴うのは4側であった.一方,SPECTではtype 3と判定されたが,rOEFが正常範囲内であった例は14側中5側(36%)であった.いずれもrCMRO2は低下し,rCBFとrCMRO2との間に不均衡は存在していないと考えられた.又,rCMRO2の観点からみると,正常範囲内に保たれていた例は14側中6側(42.9%)であった
  • A Takano, T Shiga, N Kitagawa, T Koyama, C Katoh, E Tsukamoto, N Tamaki
    PSYCHIATRY RESEARCH-NEUROIMAGING 107 (1) 45 - 50 0925-4927 2001/07 [Refereed][Not invited]
     
    Single photon emission computed tomography was used to study 14 female patients with anorexia nervosa and 8 female normal comparison subjects. Automatic voxel-based analysis of the images was carried out using statistical parametric mapping (SPM) software. Statistics across the entire brain were displayed as Z scores (threshold: P < 0.05). Compared with the normal comparison subjects, the anorectic patients were characterized by hypoperfusion in the medial prefrontal cortex and the anterior cingulate gyrus, and hyperperfusion in the thalamus and the amygdala-hippocampus complex. These results suggest that a dysfunction in neuronal circuitry may be related to anorexia nervosa. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.
  • K Yoshinaga, K Morita, S Yamada, K Komuro, C Katoh, Y Ito, Y Kuge, T Kohya, A Kitabatake, N Tamaki
    JOURNAL OF NUCLEAR MEDICINE 42 (6) 838 - 844 0161-5505 2001/06 [Refereed][Not invited]
     
    The identification of severely dysfunctional but viable myocardium is of particular importance for the selection of patients with depressed left ventricular function who will benefit from coronary revascularization. Assessment of inotropic reserve with dobutamine has recently been used for this purpose. This study compared the accuracy of low-dose dobutamine stress gated myocardial SPECT (DS SPECT) with the accuracy of dobutamine stress echocardiography (DSE) and resting perfusion SPECT for the identification of viable myocardium in patients with previous myocardial infarction. Methods: Resting and low-dose dobutamine (7.5 mug/kg/min) gated Tc-99m-tetrofosmin SPECT and echocardiography and resting F-18-FDG PET were prospectively studied in 23 patients with previous myocardial infarction and severely depressed regional function. Twenty-one of them were successfully studied with each technique. The left ventricular wall was divided into 14 segments to assess wall motion using a 5-point scale. PET viability was defined as FDG uptake greater than or equal to 50% of the maximum uptake in a region with normal wall motion. For DS SPECT and DSE studies, viable myocardium was defined as hypokinetic areas with greater than or equal to1 point improvement in wall motion. For resting perfusion SPECT, viable myocardium was defined as hypokinetic areas with a relative uptake greater than or equal to 50% of the maximum uptake. Results: Of a total of 294 segments, 55 had severe resting dyskinesis. Thirty-four segments were identified as viable on FDG PET, and 21 segments were identified as nonviable. Eleven segments were inadequately visualized with DSE, including 5 segments in the apex. Sensitivities (78% vs. 76%) and specificities (94% vs. 100%) were similar for DSE and DS SPECT, with a concordance of 86% (kappa = 0.72), DS SPECT and perfusion SPECT did not significantly differ with respect to sensitivities (76% vs. 85%, respectively). However, specificity was significantly higher for DS SPECT than for perfusion SPECT (100% vs. 52%, respectively, P < 0.05). Conclusion: This study indicated that DS SPECT correlates well with DSE in the assessment of viability, In addition, gated SPECT can evaluate regional wall motion, even in areas inadequately assessed by echocardiography. DS SPECT may also provide additional information for identifying viable myocardium, which is often overestimated by routine perfusion scans.
  • T Shiga, K Morita, A Takano, C Katoh, F Nakamura, E Tsukamoto, T Koyama, H Iida, N Tamaki
    CLINICAL NUCLEAR MEDICINE 26 (4) 334 - 339 0363-9762 2001/04 [Refereed][Not invited]
     
    Purpose: The aim of this study was to investigate the clinical value of coregistration of interictal SPECT and magnetic resonance imaging (MRI) in patients with partial epilepsy. Materials and Methods: Seventeen patients with partial epilepsy were examined with I-123 IMP or Tc-99m ethyl cysteinate dimer SPECT during the interictal phase. The SPECT images were automatically coregistered to axial T1 weighted MRIs, Asymmetry indexes (Als) were calculated in both nonregistered images and coregistered images, Results: SPECT images showed areas of decreased tracer uptake in 12 patients, in two patients, the relation between the tumor and the extent of decreased uptake became more accurate in the coregistered images. In five cases, the coregistered images clearly showed that the decreased uptake was located in the sulcus, The AIs were significantly reduced from 14.29 +/- 7.23 to 5.86 +/- 3.48 (P < 0.001) after the images were coregistered in these cases, In five cases, the coregistered images indicated that the decreased areas were in agreement with the cortical findings. No significant differences in the AIs were observed in these cases (16.50 <plus/minus> 6.19 versus 17.83 +/- 4.45). Thus, the coregistered images were useful not only to differentiate actual hypoperfusion from artificial hypoperfusion resulting from partial volume effects but also to improve the accuracy of Als. Conclusion: The coregistration of interictal perfusion SPECT and MRI is useful not only to provide precise functional and anatomic mapping but also to improve the accuracy of calculations of the semiquantitative analysis of regional cerebral blood flow parameters during the interictal state of epilepsy.
  • T Shiga, E Tsukamoto, K Nakada, K Morita, T Kato, M Mabuchi, K Yoshinaga, C Katoh, Y Kuge, N Tamaki
    JOURNAL OF NUCLEAR MEDICINE 42 (3) 414 - 419 0161-5505 2001/03 [Refereed][Not invited]
     
    There are several reports about the usefulness of F-18-FDG PET in thyroid cancer. However, few studies have compared FDG PET with I-131 and Tl-201 scintigraphy. The aim of this study was to evaluate the clinical significance of whole-body FDG PET in differentiated thyroid cancer and to compare the results with those obtained from I-131 and Tl-201 scintigraphy. Methods: Whole-body FDG PET was performed on 32 patients (10 men, 22 women; age range, 30-77 y; mean age, 54 y) with differentiated thyroid cancer (5 cases of follicular cancer and 27 of papillary cancer) after total thyroidectomy. An overall clinical evaluation was performed, including cytology, thyroglobulin level, sonography, MRI, and CT, to allow a comparison with functional imaging results for each patient. Metastatic regions were divided into five areas: neck, lung, mediastinum, bone, and other. Multiple lesions in one area were defined as one lesion. The tumor-to-background ratio (TBR) was measured for the lesions that were positive for both Tl-201 uptake and FDG PET uptake. Results: The number of lesions totaled 47, Forty-one (87%) were detected by all scintigraphic methods. FDG uptake was concordant with I-131 uptake in only 18 lesions (38%). FDG uptake was concordant with Tl-201 uptake in 44 lesions (94%), Only one lesion was negative for FDG uptake and positive for Tl-201 uptake, and two lesions were positive for FDG uptake and negative for Tl-201 uptake. A significant correlation was seen between the TBR of Tl-201 and that of FDG (r = 0.69; P < 0.05). Conclusion: These data indicate that for detecting metastatic lesions, FDG PET and I-131 scintigraphy may provide complementary information, whereas FDG PET may provide results similar to those of Tl-201 scintigraphy. Thus, the combination of I-131 scintigraphy and FDG PET (or Tl-201 scintigraphy) is the method of choice for detecting metastatic thyroid cancer after total thyroidectomy.
  • A Takano, T Shiga, J Kobayashi, Adachi, I, F Nakamura, T Koyama, C Katoh, K Morita, E Tsukamoto, N Tamaki
    NUCLEAR MEDICINE COMMUNICATIONS 22 (3) 319 - 324 0143-3636 2001/03 [Refereed][Not invited]
     
    Background Interictal brain single photon emission computed tomography (SPECT) is useful for the detection of seizure focus. Recent reports indicate a hypoperfusion in the ipsilateral thalamus as a seizure focus on interictal SPECT in temporal lobe epilepsy. In frontal lobe epilepsy (FLE), however, the alteration of perfusion in the thalamus has not been well documented. This study aimed to assess whether perfusion analysis on the thalamus may add useful information for the detection of epileptic foci in patients with FLE. Methods Interictal brain SPECT was performed in 11 patients with FLE. The asymmetry index for the thalamus and frontal area in the SPECT image was calculated in order to compare the laterality of the seizure foci. Results Thalamic asymmetry was seen in seven patients (64%), while cortial asymmetry was seen in six patients (55%). The concordance with the lateralization of the seizure foci was 6/7 (86%) in the thalamus, and 4/6 (67%) in the frontal area. Four patients showed only thalamic asymmetry. Concordance with the lateralization of the seizure focus was found in all of them. Conclusion These preliminary results suggest that hypoperfusion in the thalamus may have a complementary role to lateralize the epileptic foci in patients with FLE. ((C) 2001 Lippincott Williams & Wilkins).
  • H Ukkonen, J Knuuti, C Katoh, H Iida, H Sipila, P Lehikoinen, K Nagren, LM Voipio-Pulkki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE 28 (3) 334 - 339 0340-6997 2001/03 [Refereed][Not invited]
     
    Carbon-11 acetate positron emission tomography (PET) has been widely used to assess regional oxidative metabolism of the heart. However, the accuracy of [C-11]acetate PET in assessing oxidative metabolism in infarcted myocardium remains controversial. Thirteen patients with stable coronary artery disease and old myocardial infarction were studied. The O-15-based PET studies yielded regional blood flow (rMBF, ml/min/g) and oxygen consumption (rMMRO(2), ml/min/g), which was compared with the myocardial clearance rate constant (k(mono)) of [C-11]acetate in segments with rMBF greater than or equal to 75% (group A), 50%-74% (group B) or <50% (group C) of the normal reference segment. Mean MBF was 0.96<plus/minus>0.08 ml/g/min in group A, 0.67 +/-0.06 ml/g/min in group B and 0.42 +/-0.07 ml/g/min in group C segments. The segmental rMMRO(2) correlated linearly with k(mono) (r=0.89, P<0.001, y=0.61x+0.026). The k(mono)/rMMRO(2) ratio was comparable in the group A and B segments (0.99<plus/minus>0.19 vs 1.07 +/-0.21, P=NS). However, the ratio was significantly higher in the group C segments (1.28 +/-0.35, P=0.037). It is concluded that k(mono) of [C-11]acetate correlates linearly with rMMRO(2) determined by [O-15]O-2 inhalation. However, k(mono) appears to yield higher rMMRO(2) estimates than the [O-15]O-2 method in low-flow areas.
  • Nagara Tamaki, Yuji Kuge, Chietsugu Katoh
    Nuclear Medicine Communications 22 (8) 847 - 850 1473-5628 2001 [Refereed][Not invited]
  • K. Kato, S. Kondo, S. Hirano, M. Omi, Y. Ambo, S. Okushiba, H. Katoh
    Hepato-Gastroenterology 48 (39) 840 - 841 0172-6390 2001 [Refereed][Not invited]
     
    A 67-year-old woman was admitted to our institution for hepatic encephalopathy. Careful examination revealed a large gastrorenal shunt. On an occlusion test of the gastrorenal shunt using a balloon catheter, portal vein pressure increased to as high as 26cm H2O from the pretest value of 17.5cm H2O. From the significant increase of portal vein pressure, it was thought that simple closure of the shunt could cause postoperative formation of an esophageal varix and its rupture. We thus performed shunt closure with distal splenorenal shunt with splenopancreatic and gastric disconnection to prevent the hazard. In treating the encephalopathy caused by a spontaneous shunt, it is one of the options to perform distal splenorenal shunt with splenopancreatic and gastric disconnection in addition to shunt closure if a remarkable increase of portal vein pressure is observed by the shunt occlusion test.
  • J. Matsumoto, S. Kondo, S. Okushiba, T. Morikawa, H. Sugiura, A. Omi, S. Hirano, Y. Ambo, H. Katoh, M. Fujita, M. Shimizu
    Hepato-Gastroenterology 48 (39) 647 - 649 0172-6390 2001 [Refereed][Not invited]
     
    We report a case of biliary cystoadenocarcinoma of the liver with superficial spread to the extrahepatic bile duct. Preoperative endoscopic retrograde cholangiography revealed communication between a 4.5-cm cyst in segment 4 of the liver and the bile duct. From the findings obtained by peroral cholangioscopy and intraoperative cholangioscopy, the granular mucosa in the bile duct was diagnosed as superficially spreading cancer. The right posterior segmental bile duct and the right anterior segmental bile duct were resected at the point where the spread of cancer was no longer traceable and left lobectomy plus caudate lobectomy was carried out. This achieved radical resection, leaving the resected margin of the bile duct free from cancer. Histopathologically, well-differentiated papillary adenocarcinoma was found on the inner surface of the cyst, and the cancer had superficially spread from the cyst to the extrahepatic bile duct via the 2.5-mm diameter communication between the cyst and bile duct. The cancer was limited only to the mucosal layer all over the lesion. When performing radical surgery for biliary nocarcinoma, it is recommended that cholangioscopy be performed to examine whether the cancer has superficial spread to the extrahepatic bile duct or not. Bile duct resection should be carried out, depending on the extent of the superficial spread, so that the resected margin of the bile duct is free from cancer.
  • S. Hirano, S. Kondo, M. Omi, Y. Anbo, H. Katoh
    Hepato-Gastroenterology 48 (40) 1110 - 1113 0172-6390 2001 [Refereed][Not invited]
     
    Background/Aims: Whereas endoscopic therapy is hardly effective, distal splenorenal shunt is expected to have permanent hemostatic effects on the esophagogastric varices complicated with hepatocellular carcinoma and to sustain favorable general condition of the patient. In this study, we examined the effects of the shunt in the patients who developed hepatocellular carcinoma during the follow-up of the shunt operation. Methodology: Among the patients who had undergone distal splenorenal shunt operation for portal hypertension caused by cirrhosis, we selected only those who developed hepatocellular carcinoma during the follow-up, and then we reviewed our treatment of hepatocellular carcinoma. Results: Hepatocellular carcinomas developed postoperatively in 12 out of 59 patients with the shunt operation. At onset of the carcinomas, the varices were well controlled with no risk of bleeding and the liver function was reasonably maintained and pancytopenia was alleviated, compared to those at shunt operation. We performed hepatectomy in 4 cases and nonoperative therapies in 8 cases. After the therapies, no variceal bleeding occurred. Those therapies caused minor complications but no death. Conclusions: Distal splenorenal shunt is a useful therapy for postcirrhotic esophagogastric varices as it enables us to safely perform therapies for the hepatocellular carcinomas that develop during the follow-up period.
  • J. Matsumoto, S. Kondo, S. Okushiba, T. Morikawa, H. Sugiura, M. Omi, S. Hirano, Y. Ambo, H. Katoh
    Hepato-Gastroenterology 48 (40) 1005 - 1006 0172-6390 2001 [Refereed][Not invited]
     
    Among the intrahepatic cystic diseases except Caroli's disease, only biliary cystadenoma/cystadenocarcinoma may communicate with the bile duct. We present a case of biliary cystadenocarcinoma in which drip infusion cholangiographic-computed tomography demonstrated communication between an intrahepatic cyst and the biliary system preoperatively. Drip infusion cholangiographic-computed tomography, a simple and noninvasive examination, is useful for differentiating biliary cystadenoma/cystadenocarcinoma from other intrahepatic cystic lesions.
  • N Kubo, K Morita, C Katoh, T Shiga, M Konno, E Tsukamoto, Y Morita, N Tamaki
    EUROPEAN JOURNAL OF NUCLEAR MEDICINE 27 (10) 1525 - 1530 0340-6997 2000/10 [Refereed][Not invited]
     
    Gated myocardial perfusion single-photon emission tomography (SPET) has been used for the measurement of left ventricular (LV) function and validated by means of comparison with other imaging modalities. We have designed a new dynamic myocardial phantom in order to validate the LV function as assessed by the use of gated myocardial perfusion SPET. The phantom consists of two half-ellipsoids (an endocardial surface and an epicardial surface) and a thorax. The myocardial space is filled with a radioactive solution. The endocardial surface moves continuously towards and away from the epicardial surface in the longitudinal axis to vary the LV volume [143 ml at end-diastole (ED), 107 ml at endsystole (ES)] and thickness (apex 8 mm at ED and 26 mm at ES, midplane 8 mm). The mean values of wall motion (WM) for the epical midplane region and the basal midplane region were 5 mm and 2 mm, respectively. Gated myocardial SPET was performed during 8 and 16 intervals. These projection data sets were processed using a Butterworth filter with an order of 5 and a critical frequency of 0.34 cycles/cm. LV function was calculated using the quantitative gated SPET (QGS) algorithm. The LV function values estimated by gated SPET during 16 intervals [22% for ejection fraction (EF), 3.7 mm for WM of the apical midplane, 1.7 mm for WM of the basal midplane] closely resembled actual LV functions [25% for EE 5 mm for WM of the apical midplane, 2 mm for WM of the basal midplane]. However, the estimated values during 8 intervals were smaller than those during 16 intervals (19% for EF, 3.3 mm for WM of the apical-midplane, 1.1 mm for WM of the basal-midplane). The estimated LV volumes closely correlated with the actual volumes (r=0.99 for 16 intervals, r=0.95 for 8 intervals). Utilizing this phantom, LV function estimated using gated myocardial SPET can be compared with actual values.
  • MB Imran, K Morita, Adachi, I, M Konno, N Kubo, T Mochizuki, C Katoh, T Kohya, A Kitabatake, E Tsukamoto, N Tamaki
    INTERNATIONAL JOURNAL OF CARDIAC IMAGING 16 (4) 283 - 291 0167-9899 2000/08 [Refereed][Not invited]
     
    This study was performed to evaluate regional wall motion (WM) and wall thickening (WT) using gated myocardial perfusion single photon emission computed tomography (SPECT) and to determine their similarity and disparity in patients with coronary artery disease (CAD). A total of 44 patients underwent 1 day stress/rest (MIBI) gated SPECT. Commercially available quantitative analysis of gated SPECT (QGS) software was used to generate 3D surface display and cine-mode SPECT display. Left ventricle was divided into nine segments to score WM and WT from 0 (no abnormality) to 4 (severe abnormality) by six independent observers. Finally a mean score was calculated for each segment from the scores of six observers. There was fairly good correlation between WM and WT of individual segments (r = 0.62, p < 0.0001). Concordance rate (\WM - WT\less than or equal to1) was 85%. A large difference between WM and WT (WM - WT greater than or equal to2) was observed in 15 segments, including 12 segments with greater WM abnormalities and 3 segments with greater WT abnormalities (lateral and inferior walls). Greater WM abnormalities were most commonly observed in anteroseptal segments especially in post coronary artery bypass grafting (CABG) patients. In conclusion, WM and WT showed similarity on QGS studies. However, these two parameters may be determined separately in gated SPECT studies for comprehensive and robust evaluation of the functional status of myocardium. Analyses based on WM assessment alone may lead to erroneous results especially in septal regions.
  • S. Kondo, H. Katoh, T. Shimizu, M. Omi, S. Hirano, Y. Ambo, S. Okushiba, T. Morikawa
    Hepato-Gastroenterology 47 (35) 1447 - 1449 0172-6390 2000 [Refereed][Not invited]
     
    Background/Aims: To assess preliminary results of preoperative embolization of the common hepatic artery in preparation for distal pancreatectomy with en bloc resection of the celiac and common hepatic arteries for carcinoma of the body of the pancreas involving these arteries. Methodology: Four patients underwent the embolization with coils 1-7 (median: 5) days before surgery. A detachable coil was used to obtain the best position of the first coil as an anchor in 3 patients. Results: Immediately after embolization, collateral pathways developed from the superior mesenteric artery via the pancreatoduodenal arcades to the proper hepatic and gastroduodenal arteries in all 4 patients however, they were relatively poor in one patient. There were no complications after embolization. The pulsation of the proper hepatic and gastroduodenal arteries was well palpable during surgery, although it had been compromised sometimes in previous cases without embolization. There were no ischemia-related complications in the 2 patients who underwent radical surgery. Conclusions: Preoperative embolization of the common hepatic artery is a safe technique and has the potential to enlarge the collateral pathways by the time of distal pancreatectomy with en bloc resection of the celiac artery and prevent postoperative fatal ischemia-related complications.
  • S. Kondo, H. Katoh, M. Omi, S. Hirano, Y. Ambo, E. Tanaka, M. Kaji, S. Ohtake, K. Itoh, H. Yamada, S. Okushiba, T. Morikawa
    Hepato-Gastroenterology 47 (36) 1501 - 1503 0172-6390 2000 [Refereed][Not invited]
     
    Background/Aims: There have been no reports comparing surgical results of hepatectomy for metastases between breast cancer origin and colorectal cancer origin. The aim of the present study was to compare the both and to clarify the survival benefit brought by hepatectomy for metastases from breast cancer. Methodology: Between 1990 and 1999, 6 patients with hepatic metastases from breast cancer and 94 patients with those from colorectal cancer underwent hepatectomy with curative intent. All patients in the breast-cancer-origin group received adjuvant chemotherapy following hepatectomy, however, fewer patients (55% of the 94 patients) did in the colorectal-cancer-origin group (P=0.034). Results: Morbidity and mortality rates after hepatectomy in patients with hepatic metastases from breast cancer were 0% and 0%, respectively, and those in patients with metastases from colorectal cancer were 12% and 1%, respectively. Postoperative survival curves in the both groups were similar. Three- and five-year survival rates in the breast-cancer-origin group were 60% and 40%, respectively, and those in the colorectal-cancer-origin group were 54% and 42%, respectively. Conclusions: When appropriate adjuvant chemotherapy is performed, hepatectomy for metastases from breast cancer offers the survival benefit similar to that in hepatic metastases from colorectal cancer.
  • C Katoh, Y Kuge, K Morita, E Tsukamoto, N Tamaki, J Knuuti
    POSITRON EMISSION TOMOGRAPHY IN THE MILLENNIUM 1197 273 - 278 0531-5131 2000 [Refereed][Not invited]
     
    The aim of this study is to develop a modified method for quantifying regional myocardial blood flow (rMBF) using O-15-water and PET. Method's. The study used 22 healthy men. In this modified method, the input function was calculated by the time/activity curve in a whole myocardial tissue and in the left ventricle (LV), rMBF and spillover fraction within the myocardium (Va) were quantified with the input function and a time/activity curve in the regional myocardial tissue. The rMBF and Va were compared with those derived from the original method. A simulation study was carried out to evaluate the effects of errors in Va on the rMBF using both methods. Results. Compared with the original method, the modified one yielded lower mean rMBF (p < 0.02) and higher mean Va (p < 0.01). The simulation study demonstrated the less effects of error in Va on the rMBF value with the modified method. Conclusion. This modified method dedicates a uniform input function for each regional myocardium in each subject. This method will be expected to quantify rMBF more correctly than the original method which might underestimate the spillover Fraction and overestimate rMBF This procedure is mathematically more stable to estimate the parameters opposed to those in the original algorithm.
  • A Takano, T Shiga, J Kobayashi, F Nakamura, Adachi, I, C Katoh, Y Kuge, T Koyama, E Tsukamoto, N Tamaki
    POSITRON EMISSION TOMOGRAPHY IN THE MILLENNIUM 1197 73 - 78 0531-5131 2000 [Refereed][Not invited]
     
    FDG-PET and CBF-SPECT have been used in the evaluation of patients with temporal lobe epilepsy. In extratemporal lobe epilepsy, the utilities of FDG-PET and CBF-SPECT were still uncertain. We assessed the utility of FDG-PET and CBF-SPECT in patients with extratemporal lobe epilepsy Twelve patients with refractory extratemporal lobe epilepsy were studied in dynamic PET and CBF-SPECT imagings. With 3-compartment model analysis using nonlinear fitting, CMRglu and rate constants of influx (K1), efflux (k2), phosphorylation (k3), dephosphorylation (k4) were calculated. PET and SPECT images were evaluated visually to detect the hypoperfused area or hypometabolic area. ROI's were taken to calculate each parameter. To compare with contralateral region, % asymmetry index of each parameter was calculated. Only four of 12 patients had hypoperfusion in interictal CBF-SPECT and hypometabolism in FDG-PET. The extents of the hypoperfused regions were almost the same as that of the hypometabolic regions. These four patients had reduced K1 value in hypometabolic regions, and three patients had also reduced k3 value. In conclusion, it is not easy to detect the epileptic foci in extratemporal lobe epilepsy.. Even with use of FDG-PET and interictal CBF-SPECT combination, they have similar diagnostic information for detecting epileptic foci as independent analysis of FDG-PET or CBF-SPECT.
  • T Shiga, E Tsukamoto, T Kato, K Morita, Adachi, I, M Mabuchi, K Yoshinaga, Y Suginami, A Takano, N Tamaki, C Katoh, Y Kuge
    POSITRON EMISSION TOMOGRAPHY IN THE MILLENNIUM 1197 181 - 185 0531-5131 2000 [Refereed][Not invited]
     
    Purpose. The aim of the present study was to evaluate the clinical significance of whole-body F-18 FDG PET in differentiated thyroid cancer and to compare the results with I-131 and T1-201 scintigraphy. Patients and Methods. Whole-body FDG-PET imaging was performed during the follow-up 31 patients (27-77 years old, F:M = 23:8, four with follicular cancer and 27 with papillary cancer) suffering from differentiated thyroid cancer after total thyroidectomy! An overall clinical evaluation was done including cytology, thyroglobulin level, sonography and computed tomography to allow a comparison with functional imaging results for each patient. Metastasis regions were divided into six areas: neck, lung, mediaternum, bone, others, unknown. Multiple lesions in one area were counted as one lesion. Results. There were 31 lesions in 29 patients. Compared with I-131 scintigraphy, FDG uptakes were concordant with I-131 uptakes only in 15 lesions. (36%) Compared with T1-201, FDG uptakes were concordant with T1-201 in 37 lesions (90%). Conclusion. For detecting metastatic lesions, FDG-PET and I-131 scintigraphy give complementary information whereas FDG-PET demonstrated similar Results to TI-201 scintigraphy. I-131 plus FDG-PET (or T1-201 scan) is a method of choice for detecting metastatic thyroid cancer after total thyroidectomy.
  • K Morita, C Katoh, K Koshinaga, Adachi, I, T Shiga, M Mabuchi, Y Itoh, M Konno, T Kohya, A Kitabatake, Y Kuge, E Tsukamoto, N Tamaki
    POSITRON EMISSION TOMOGRAPHY IN THE MILLENNIUM 1197 141 - 145 0531-5131 2000 [Refereed][Not invited]
     
    The aim of this study is to assess the quantification of regional myocardial glucose utilization (MGU) using positron emission tomography (PET) and fluorine-18 deoxyglucose (FDG). Methods. Six patients with LV dysfunction and six healthy volunteers were enrolled in this study. A dynamic PET study was performed for 40 min following an injection of 370 MBq of FDG under a 50 g glucose loading condition. The input function was assessed from the time-activity curve drawn in left atrial cavity on dynamic PET images. LV was divided into eight segments, and the values of MGU were calculated using a three-compartment model. The values of K1, k2, k3 were calculated and SUV using static images was also assessed. Results. The values of MGU in the patients were significantly higher than the healthy volunteers (41.1 +/- 16.5 vs. 27.6 +/- 13.6 mu mol/100 g/min, p < 0.0001). There was a significant correlation between MGU and SUV (r = 0.82, p < 0.0001). The values of K1 in patients were higher than those in the healthy volunteers, but there was no significant difference in k3 values. Conclusions. Quantitative assessment of MGU may provide a useful information of regional myocardial metabolic status. These preliminary data indicate that glucose utilization was enhanced mainly due to increase of K1 value in patients with LV dysfunction.
  • T Kato, E Tsukamoto, Y Suginami, M Mabuchi, K Yoshinaga, A Takano, Adachi, I, T Shiga, K Morita, C Katoh, Y Kuge, N Tamaki
    POSITRON EMISSION TOMOGRAPHY IN THE MILLENNIUM 1197 221 - 224 0531-5131 2000 [Refereed][Not invited]
     
    It is important to know normal FDG accumulation in major organs for interpreting whole-body FDG-PET. Twenty-eight normal subjects were studied in whole-body PET imaging. The intensity of FDG uptake in organs was evaluated, and the factors which caused the variability of normal FDG accumulation were examined. Emission images were acquired and reconstructed using filtered back-projection without attenuation correction. FDG uptake was classified into four grades visually. The oral cavity, the liver, the stomach, and the colon were visualized in all subjects. Especially the oral cavity frequently showed "high" grade uptake. The laryngeal and cervical muscles, and the heart showed variable FDG accumulation. The fasting time was shorter in subjects whose heart showed "high" accumulation than in those who showed less accumulation (p < 0.05). Serum concentration of free fatty acid was significantly lower in them, too (p < 0.05). No association was found between FDG uptake in organs and subject's age. Careful evaluation is necessary to distinguish abnormal accumulation from normal variation in the oral cavity, the laryngeal and cervical muscles, and the heart. A longer fasting time is better to avoid myocardial uptake and may lead to reduced misinterpretation.
  • E Tsukamoto, K Itoh, K Morita, C Katoh, K Nakada, K Nonomura, H Kakizaki, T Koyanagi, N Tamaki
    ANNALS OF NUCLEAR MEDICINE 13 (6) 401 - 406 0914-7187 1999/12 [Refereed][Not invited]
     
    We reviewed Tc-99m DMSA scintigraphy in children with vesicoureteral reflux (WR) in order to assess whether repeated Tc-99m DMSA scans are necessary for the follow up of these patients. Ninety-seven children who were followed up for more than one year (1-7.4 years, average 2.8 years) after the first DMSA scan were included in the study. Fifty-one patients had been diagnosed as primary VUR and 46 as secondary VUR. Age at the first examination ranged from 0 to 14 years (average 5.1 years). Planar images were taken 2 hours after injection. The % renal uptake per injected dose (%RU) was calculated from posterior images. Kidneys in Il patients (11.3%) changed morphologically during the follow up. Of these, new photon deficient areas (PD) were detected in only 4 patients (4.1%). All of these 4 patients had neurogenic bladder and were managed with self-catheterization. Of the remaining 7 patients, cortical thinning progressed in 5 patients (5.2%) and PDs resolved in 3 patients (3.1%). In one of these 7 patients, PD resolved in one kidney and cortical thinning progressed in the contralateral kidney. Of 97 patients reviewed, % RU decreased more than 20% during the follow up in 6 patients (6.2%). All were diagnosed as secondary VUR due to neurogenic bladder. % RU decreased only in the contracted kidneys at the initial scan. Two of them underwent renal transplantation because of severe renal failure. In conclusion, new PD rarely developed and % RU decreased in only a few patients during the follow up of children with VUR. Repeated Tc-99m DMSA scintigraphy therefore seems to have little benefit in the follow up of children with VUR. It should be performed in selected patients with high risk of urinary tract infection or renal failure.
  • E Tsukamoto, K Itoh, C Katoh, T Mochizuki, T Shiga, K Morita, N Tamaki
    ANNALS OF NUCLEAR MEDICINE 13 (6) 383 - 387 0914-7187 1999/12 [Refereed][Not invited]
     
    Renal uptake of Tc-99m-DMSA has been quantified by various methods. The aim of this study is to obtain a normal value for Tc-99m-DMSA renal uptake calculated by the posterior view method and age variation, and to assess its clinical validity. Scintigrams of 238 children (0-12 years) with Tc-99m-DMSA were reviewed. All the children had a clinical history of primary vesicoureteral reflux and/or neurogenic bladder, ureteral or urethral anomalies. Their kidneys were divided into two groups, "normal" and "abnormal" according to their scintigraphic findings and split renal functions. Percent renal uptake per injected dose (% RU) was quantitated from planar images at 2 hours after injection of an age-adjusted dose (26-95 MBq) of Tc-99m-DMSA. Calculated total % RU, individual % RU of the right and left kidneys (mean +/- sd) in patients with normal kidneys were 40.7 +/- 5.0%, 20.2 +/- 3.0%, 20.4 +/- 2.7%, respectively. There was no significant correlation between % RU and age (r = 0.231). Longitudinal variation in the % RU in 9 patients ranged from 1.2% to 18%. Our conventional method for quantifing % RU is simple, practical and feasible in routine clinical practice, especially for children under follow up.
  • KUGE Yuji, TSUKAMOTO Eriko, KATOH Chietsugu, SEKI Koh-ichi, OHKURA Kazue, OHMIYA Yasuhiro, NISHIJIMA Ken-ichi, TANAKA Akira, SASAKI Motoji, TAMAKI Nagara
    Kaku Igaku 36 (8) 873 - 878 0022-7854 1999/10/20 [Refereed][Not invited]
  • Laine H, Katoh C, Luotolahti M, Yki-Järvinen H, Kantola I, Jula A, Takala TO, Ruotsalainen U, Iida H, Haaparanta M, Nuutila P, Knuuti J
    Circulation 100 (24) 2425 - 2430 1999/10 [Refereed][Not invited]
     
    Laine H, Katoh C, Luotolahti M, Yki-Jarvinen H, Kantola I, Jula A, Takala TO, Ruotsalainen U, Iida H, Haaparanta M, Nuutila P and Knuuti J. : Myocardial oxygen consumption is unchanged but efficiency is reduced in patients with essential hypertension and left ventricular hypertrophy.Circulation 100:2425-2430(1999)
  • TO Takala, P Nuutila, C Katoh, M Luotolahti, J Bergman, M Maki, Oikonen, V, U Ruotsalainen, T Gronroos, M Haaparanta, S Kapanen, J Knuuti
    AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM 277 (4) E585 - E590 0193-1849 1999/10 [Refereed][Not invited]
     
    We have previously demonstrated reduced myocardial glucose uptake rates in hearts of endurance athletes, which could be due to increased use of alternative fuels or reduced energy demands. In the present study myocardial blood flow, oxygen consumption, and free fatty acid uptake were measured with [O-15]H2O, [O-15]O-2, [F-18]FTHA, and positron emission tomography (PET) in 9 endurance athletes and 11 sedentary men during euglycemic hyperinsulinemia. Compared with sedentary men, athletes had 33% lower myocardial blood flow, 27% lower oxygen consumption, and 20% lower estimated myocardial work per gram of tissue. Myocardial fatty acid uptake rates were not significantly different in endurance athletes (0.83 +/- 0.29) and sedentary men (1.0 +/- 0.31 mu mol.100 g(-1).min(-1), P = 0.232). In conclusion, myocardial blood dow and oxygen consumption per unit mass of myocardium are reduced at rest in endurance athletes. This can be explained by reduced energy requirements per gram of tissue due to anatomic and physiological changes of the athlete's heart.
  • K Nakada, C Katoh, K Morita, K Kanegae, E Tsukamoto, T Shiga, T Mochizuki, N Tamaki
    JOURNAL OF NUCLEAR MEDICINE 40 (6) 963 - 967 0161-5505 1999/06 [Refereed][Not invited]
     
    A prospective study of Tl-201 uptake was performed to compare Tl-201 uptake with nuclear deoxyribonucleic acid (DNA) content and clinical behavior of tumors in metastatic thyroid carcinoma and to assess the significance of Tl-201 uptake in evaluating clinical characteristics of thyroid carcinoma. Methods: Fifty-six patients with metastases of differentiated thyroid carcinoma had Tl-201 scintigraphy. Grade of Tl-201 uptake was semiquantitatively assessed according to tumor-to-background ratio on 2-h late scan. Nuclear DNA content was analyzed within 3 wk of Tl-201 study by flow cytometry using biopsy material and was classified as diploidy or aneuploidy. Patients were followed up to examine incidence of tumor growth and/or anaplastic transformation. Results: DNA content was diploidy in 48 patients and aneuploidy in 8 patients. Tl-201 uptake in the DNA-aneuploid group (2.61 +/- 0.29) was significantly higher than that in the DNA-diploid group (1.82 +/- 0.35, P < 0.01 for both groups). Tumor growth was observed in ail patients with DNA aneuploidy but in only 5 of 48 patients with DNA diploidy (P < 0.01). Anaplastic transformation was observed in 3 patients in the DNA-aneuploid group but in none of the patients in the DNA-diploid group. Conclusion: High Tl-201 uptake indicates greater incidence of abnormal DNA content with aggressive clinical behavior of metastatic tumors. Thus, Tl-201 scintigraphy may be useful in characterizing metastatic thyroid carcinoma and in identifying those patients with poorer prognoses.
  • C Katoh, U Ruotsalainen, H Laine, S Alenius, H Iida, P Nuutila, J Knuuti
    JOURNAL OF NUCLEAR MEDICINE 40 (5) 862 - 867 0161-5505 1999/05 [Refereed][Not invited]
     
    The aim of this study was to compare reproducibility and accuracy of two reconstruction methods in quantification of myocardial blood flow and oxygen metabolism with O-15-labeled tracers and PET. A new iterative Bayesian reconstruction method based on median root prior (MRP) was compared with filtered backprojection (FBP) reconstruction method, which is traditionally used for image reconstruction in PET studies. Methods: Regional myocardial blood flow (rMBF), oxygen extraction fraction (rOEF) and myocardial metabolic rate of oxygen consumption (rMMRO(2)) were quantified from images reconstructed in 27 subjects using both MRP and FBP methods. For each subject, regions of interest (ROls) were drawn on the lateral, anterior and septal regions on four planes. To test reproducibility, the ROI drawing procedure was repeated. By using two sets of ROls, variability was evaluated from images reconstructed with the MRP and the FBP methods. Results: Correlation coefficients of significantly higher in the images reconstructed with the MRP reconstruction method compared with the images reconstructed with the FBP method (rMBF: MRP r= 0.896 versus FBP r= 0.737, P< 0.001; rOEF: 0.915 versus 0.855, P < 0.001; rMMRO(2): 0.954 versus 0.885, P < 0.001). Coefficient of variation for each parameter was significantly lower in MRP Images than in FBP images (rMBF: MRP 23.5% +/- 11.3% versus FBP 30.1% +/- 14.7%, P < 0.001; rOEF: 21.0% +/- 11.1% versus 32.1% +/- 19.8%, P <0.001; rMMRO(2): 23.1% +/- 13.2% versus 30.3% +/- 19.1%, P < 0.001). Conclusion: The MRP reconstruction method provides higher reproducibility and lower variability in the quantitative myocardial parameters when compared with the FBP method. This study shows that the new MRP reconstruction method improves accuracy and stability of clinical quantification of myocardial blood flow and oxygen metabolism with O-15 and PET.
  • Takashi Kato, Eriko Tsukamoto, Yuko Suginami, Megumi Mabuchi, Keiichiro Yoshinaga, Akihiro Takano, Itaru Adachi, Tohru Shiga, Koichi Morita, Chietsugu Katoh, Yuji Kuge, Nagara Tamaki
    Kakuigaku 36 (9) 976 - 977 0022-7854 1999 [Refereed][Not invited]
     
    It is important to know FDG accumulation in the normal distributions for interpreting whole-body PET imaging for tumor detection. Twenty-eight normal subjects were studied with whole-body PET imaging and were examined the intensity of FDG uptake in major organs and the factors which caused it's variety. Emission images were acquired and images were reconstructed without attenuation correction. The intensity of FDG uptake was classified into 4 grades visually. No accumultion was found in the thyroid, the esophagus, and the spleen. The oral cavity, the liver, the stomach, and the colon were visualized in all subjects. The laryngeal muscle, the cervical muscle, and the heart accumulated FDG with various grade from 1 to 4 grades. No association was found between the in-tensity of uptake in the organs and volunteer's age. The fasting time was shorter in volunteers whose heart showed "high" grade than those showed less accumulation (p< 0.05). Serum concentration of free fatty acid was significantly lower in them, too (p< 0.05). Various FDG uptake was observed in many organs, especially the laryngeal muscle, the cervical muscle, and the heart. In our study, there was no facter which caused FDG uptake in organs except for the fasting time and the value of free fatty acid in the heart. Such analysis of whole-body FDG distributions in the normal subjects is valuable for tumor detection with FDG-PET.
  • K. Itoh, E. Tsukamoto, T. Mochizuki, K. Kanegae, C. Katoh, N. Tamaki
    Kakuigaku 35 (8) 689 - 695 0022-7854 1998 [Refereed][Not invited]
     
    We compared relationship among three single blood sampling methods which have been proposed for determination of plasma clearance with 99mTc-MAG3. Russell's and Bubeck's algorithms were employed for 48 adults (average age: 53 years) and Bubeck's and Piepsz's algorithms were used in 9 children (average age: 5.8 years). Three methods showed very high correlation among them. However, Russell's and Piepsz's methods were about 1.4 times higher than Bubeck's method in calculating plasma clearance of 99mTc-MAG3. The present study indicates that three methods discussed here are useful for the determination of plasma clearance with 99mTc-MAG3. In addition, Bubeck's method may be preferable as a reference for single plasma sampling method because of common application to adults and children.
  • Takafumi Mochizuki, Eriko Tsukamoto, Tomohide Ono, Kazuo Itoh, Kakuko Kanegae, Chietsugu Katoh, Tohru Shiga, Kunihiro Nakada, Tetsuro Kohya, Nagara Tamaki
    Annals of Nuclear Medicine 11 (4) 299 - 306 0914-7187 1997 [Refereed][Not invited]
     
    Changes in myocardial perfusion and metabolism are often associated with myocardial hypertrophy, but there are few reports describing the serial assessment of fatty acid metabolism in hypertrophic myocardium. The aim of this study is to assess fatty acid metabolism serially in hypertrophic myocardium in spontaneously hypertensive rats (SHR) with 125I-BMIPP, a branched fatty acid analog. Methods: SHR and Wistar-Kyoto rats (WKY) as the control were divided into 4 groups (12, 15, 18 and 51 weeks after birth). The heart was extracted 10 minutes after intravenous injection of 125I-BMIPP and 201Tl at the same time. The accumulation of each radiotracer in the myocardium was counted with a well gamma counter. In addition, 125I-BMIPP uptake was corrected by 201Tl uptake (B/T). Results: The heart weight/body weight ratio was significantly higher in SHR than that in WKY (p < 0.001). In SHR, this ratio increased up to 18 weeks (12 weeks 0.266 ± 0.005, 18 weeks 0.281 ± 0.006: mean ± SE, p < 0.05). The 125I-BMIPP uptake tended to be significantly reduced in SHR (12 weeks 2.373 ± 0.212, 18 weeks 1.380 ± 0.047: mean ± SE, p < 0.05). Such a difference in BMIPP uptake was more evident when BMIPP uptake was more corrected by Tl uptake (B/T), but no regional difference or heterogeneity of BMIPP distribution was observed in the hypertrophic myocardium in SHR. Conclusion: A change in fatty acid metabolism with age was observed in association with myocardial hypertrophy in this hypertensive rat model, which was well demonstrated with 125I- BMIPP and 201Tl.
  • E Tsukamoto, K Itoh, C Katoh, K Kanegae, K Nakada, T Shiga, T Mochizuki, M Yamamuro, N Tamaki
    NUCLEAR MEDICINE COMMUNICATIONS 18 (1) 53 - 56 0143-3636 1997/01 [Refereed][Not invited]
     
    Tc-99(m)-dimercaptosuccinic acid (Tc-99(m)-DMSA) planar and single photon emission tomographic images from 100 children were reviewed to analyse whether linear defects corresponding to anatomical characteristics of interrenuncular septum (IRS) could be seen. Thirty sites in 30 kidneys (20 right, 10 left) from 27 patients were determined as showing IRS. They were seen less frequently in patients less than 7 years of age. The prevalence of IRS in the patients with vesico-ureteric reflux (VUR) was not significantly different from that in the patients without VUR. The interrenuncular septum was never seen on planar images and was most clearly demonstrated on conventional coronal tomographic images. The linear defects ascribed to IRS on Tc-99(m)-DMSA scintigrams were of a similar incidence to that reported previously. However, IRS is still an unestablished structure, and there is no evidence that these Linear defects actually correspond to the structure described as the interrenuncular septum.
  • Nakada K, Kasai K, Watanabe Y, Katoh C, Kanegae K, Tsukamoto E, Itoh K, Tamaki N
    Ann Nucl Med. 10 (4) 441 - 444 0914-7187 1996/11 [Refereed][Not invited]
  • Nakada K, Katoh C, Kanegae K, Tsukamoto E, Itoh K, Tamaki N
    Ann Nucl Med 10 (2) 171 - 176 0914-7187 1996/05 [Refereed][Not invited]
  • Nakada K, Katoh C, Kanegae K, Tsukamoto E, Itoh K, Furudate M, Tamaki N
    Ann Nucl Med 10 (1) 41 - 48 0914-7187 1996/02 [Refereed][Not invited]
  • CHIETSUGU KATOH, KUNIHIRO NAKADA, RIWA KISHIMOTO, HAJIME OGAWA, KAZUO ITOH, MASAYORI FURUDATE
    Nippon ACTA Radiologica 日本医学放射線学会 55 (12) 902 - 907 0048-0428 1995/10 [Refereed][Not invited]
  • H. Katoh, S. Hirano, K. Satoh
    Japanese Journal of Geriatrics 31 (1) 33 - 37 0300-9173 1994 [Refereed][Not invited]
     
    Between January, 1980 and December, 1992, 256 patients underwent resection of pancreatobiliary carcinoma. Sixty eight of these patients were more than 70 years old and are the subject of this review. The morbidity rate for pancreatic cancer patients undergoing pancreaticoduodenectomy was 50%. The five years survival rate was 15%. The morbidity rate for biliary cancer patients undergoing major resection was 40%. The five year survival rate was 40%. The data presented demonstrate that extended operation for pancreatic cancer should not be performed in the elderly patients but major resection for biliary cancer can be performed, even in elderly patients, with a low but somewhat increased mortality risk. Methods of estimating risk factor for elderly patients are required.
  • C. Kato
    Kakuigaku 31 (6) 565 - 579 0022-7854 1994 [Refereed][Not invited]
     
    A frequency domain filtering method provides accurate frequency response. In order to provide optimal radionuclide image quality, Butterworth or Wiener filters were applied in the frequency domain. A method is developed to determine automatically their optimal parameters from the power spectra of the object images. Phantom studies showed that proper parameters were derived by this method. Thirty-one cases of multigated cardiac blood-pool images and phantom images modeled on the cardiac images were filtered by 3 x 3 points temporal smoothing, frequency domain Butterworth and Wiener filters. From these images, ejection fractions were calculated and evaluated the correlation between the actual ejection fractions in the phantom study or the values derived from the contrast left ventriculography. The better correlation coefficients were derived with the frequency domain Butterworth filter than with the temporal smoothing. And more desirable correlation coefficients were derived with the frequency domain Wiener filter than with the frequency domain Butterworth filter, especially in the low count studies. Butterworth or Wiener filtering in the frequency domain reduces noise and improves the capacity for quantitative analysis in the radionuclide images.
  • H. Shibata, M. Kohno, H. Katoh
    Journal of Toxicological Sciences 14 (2) 67 - 75 0388-1350 1989 [Refereed][Not invited]
     
    The effect of α-naphthylisothiocyanate (ANIT) on blood clearance of 99mTc-phytate (99mTc-P) in dogs was examined, and blood clearance test of 99mTc-P was compared with the cases of serum transaminase test or serum bilirubin test. Serum transaminase and bilirubin levels in dogs increased after ANIT administration, however, the degree of increase in these parameters was much lower than the cases in rats. The disappearance rate of 99mTc-P from blood in dogs decreased with the increase in dose of ANIT and with the passage of time after the ANIT administration. Changes of the blood clearance of 99mTc-P after ANIT treatment in dogs may be influenced by the disorder in the hepatocytes rather than in the bile ductule cells. The blood clearance test of 99mTc-P in dogs showed a sensitive reaction for the acute hepatic dysfunction induced by ANIT equally to the serum transaminase test or the serum bilirubin test.

Books etc

  • 消化器内視鏡技師のためのハンドブック 改訂第8版
    日本消化器内視鏡学会 (Joint work検査の実際 上部消化管検査（経口法）143-149頁)
    医学図書出版 2023/10 (ISBN: 9784865175554)
  • 加藤, 千恵次, 孫田, 惠一, 杉森, 博行 (Supervisor1-62頁)
    メジカルビュー社 2020/03 (ISBN: 9784758320191) xiv, 274p

Conference Activities & Talks

  • Clinical molecular imaging and image analysis  [Invited]
    Chietsugu Katoh
    6th. GCB (Global Center for Biomedical science and engineering) Summer School for Molecular Biomedical Science and Diagnosis, Sapporo  2023/08
  • 15O-CO2ダイナミック脳PET検査におけるディープラーニングによる脳血流定量画像の推定  [Not invited]
    奥村脩一郎, 加藤千恵次, 孫田惠一, 平田健司
    日本放射線技術学会 第79回総会学術大会、横浜市  2023/04
  • Development and validation of 2.5-dimensional superresolution convolutional neural network for whole-body PET images  [Not invited]
    Hiroki Endo, Kenji Hirata, Chietsugu Katoh, Keiichi Magota, Kousuke Kudo
    Annual Congress of the European Association of Nuclear Medicine (EANM), Barcelona, Spain  2022/10
  • Estimation of CT images from PET images without non-attenuation-corrected PET images using GAN  [Not invited]
    Mui Saito, Kentaro Nishigami, Chietsugu Katoh
    Annual Congress of the European Association of Nuclear Medicine (EANM), Barcelona, Spain  2022/10
  • Estimating attenuation-corrected PET images using GAN from non-attenuation-corrected PET images  [Not invited]
    Kentaro Nishigami, Mui Saito, Chietsugu Katoh
    Annual Congress of the European Association of Nuclear Medicine (EANM), Barcelona, Spain  2022/10
  • Improvement of the detectability of perfusable tissue fraction and myocardial flow reserve after revascularization by 15O-water ECG-gated PET  [Not invited]
    Ayaka Ochiai, Chietsugu Katoh
    Annual Congress of the European Association of Nuclear Medicine (EANM), Barcelona, Spain  2022/10
  • ディープラーニングによる非減弱補正PET画像を用いた減弱補正用CT像の推定  [Not invited]
    斉藤 道紀, 加藤千恵次
    第42回日本核医学技術学会総会学術大会、京都市  2022/09
  • GANを利用したPET減弱補正に関する検討  [Not invited]
    西上健太朗, 齊藤道紀, 加藤千恵次
    第42回日本核医学技術学会総会学術大会、京都市  2022/09
  • 18F-FDGダイナミック脳PET検査におけるCNNを用いたCMRGlc(脳局所糖代謝)の推定
    前川 楓稀, 加藤千恵次
    第42回日本核医学技術学会総会学術大会, 京都市  2022/09
  • CNNによる15O-CO2ダイナミック脳PETの非侵襲的な入力関数推定  [Not invited]
    奥村 脩一郎, 加藤千恵次
    第42回日本核医学技術学会総会学術大会, 京都市  2022/09
  • Clinical molecular imaging and image analysis  [Invited]
    Chietsugu Katoh
    5th GCB(Global Center for Biomedical science and engineering) Summer School for Medical Physics, Sapporo  2022/08
  • 15O-CO2 ダイナミック脳PET検査における非侵襲的な入力関数の推定  [Not invited]
    奥村脩一郎, 加藤千恵次, 髙木耀介, 孫田惠一, 平田健司
    日本放射線技術学会 第78回総会学術大会, 横浜  2022/04
  • 非減弱補正PET画像からのディープラーニングによる線減弱係数用CT像の推定
    齋藤道紀, 西上健太朗, 加藤千恵次, 平田健司, 孫田惠一
    日本放射線技術学会 第78回総会学術大会、横浜  2022/04
  • 非減弱補正PET画像からのGANを用いた減弱補正PET画像の推定  [Not invited]
    西上健太朗, 齋藤道紀, 加藤千恵次, 孫田惠一, 平田健司
    日本放射線技術学会 第78回総会学術大会、横浜  2022/04
  • Clinical molecular imaging and image analysis  [Invited]
    Chietsugu Katoh
    8th GI-CoRE GCB Summer School in 2022 Winter for Medical Physics, Sapporo  2022/03
  • ROI interpolation algorithms to accelerate training data preparation for AI segmentation  [Not invited]
    Hiroki Endo, Kenji Hirata, Keiichi Magota, Chietsugu Katoh
    第61回日本核医学会学術総会、名古屋  2021/11
  • Non-invasive estimation of the input function with CNN in 18F-FDG dynamic brain PET study  [Not invited]
    加藤千恵次, 石山敬悟, 孫田惠一, 平田健司
    第61回日本核医学会学術総会、名古屋  2021/11
  • GANを用いたPET画像のSUV補正  [Not invited]
    西上健太朗, 加藤千恵次
    第41回日本核医学技術学会総会学術大会、名古屋  2021/11
  • 18F-FDGダイナミック脳PETスキャンにおけるディープラーニングを用いた短時間収集画像の画質改善の試み  [Not invited]
    斉藤道紀, 加藤千恵次
    第41回日本核医学技術学会総会学術大会、名古屋  2021/11
  • 15O-CO2ダイナミック脳PET検査におけるCNNによる非侵襲的な入力関数の推定  [Not invited]
    高木 耀介, 加藤千恵次
    第41回日本核医学技術学会総会学術大会、名古屋  2021/11
  • 18F-FDG-PET/CT検査のCT画像における大動脈の物体検出  [Not invited]
    下川 裕平, 加藤千恵次
    第41回日本核医学技術学会総会学術大会、名古屋  2021/11
  • 18F-FDG dynamic brain PET study estimating the arterial plasma radioactivity curve using a convolutional neural network (CNN)  [Not invited]
    Keisuke Kawauchi, Chietsugu Katoh
    Annual Congress of the European Association of Nuclear Medicine (EANM'21) Web meeting  2021/10
  • GANを用いたPET画像の画質改善についての検討  [Not invited]
    西上 健太朗, 加藤千恵次
    第60回日本生体医工学会北海道支部大会、札幌  2021/10
  • 18F-FDGダイナミック脳PETスキャンにおけるディープラーニングを用いた短時間収集画像の画質改善のアルゴリズム開発の試み  [Not invited]
    斉藤 道紀, 加藤千恵次
    第60回日本生体医工学会北海道支部大会、札幌  2021/10
  • Strategy to estimate the time-activity curve of arterial plasma in 18F-FDG dynamic brain PET study with Convolutional Neural Network  [Not invited]
    Chietsugu Katoh, Keigo Ishiyama, Keiichi Magota, Kenji Hirata
    Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2021 annual meeting, Washington DC, USA (Web meeting)  2021/06
  • Estimation of 10-minute acquired images from 5-minute acquired images using deep learning in 18F-FDG dynamic PET scan  [Not invited]
    Mui saito, Kentaro Nishigami, Chietsugu Katoh, Kenji Hirata, Keiichi Magota
    第77回日本放射線技術学会総会学術大会、横浜  2021/04
  • Evaluation of Super-Resolution of PET Images Using Generative Adversarial Network  [Not invited]
    Kentaro Nishigami, Mui saito, Chietsugu Katoh, Keiichi Magota, Kenji Hirata
    第77回日本放射線技術学会総会学術大会  2021/04
  • Development and study of 3D super-resolution convolutional neural network for PET images  [Not invited]
    Hiroki Endo, Chietsugu Katoh, Kenji Hirata, Keiichi Magota
    第77回日本放射線技術学会総会学術大会、横浜  2021/04
  • Estimation of time-activity curve of arterial plasma in the 18F-FDG dynamic PET study using Deep-learning  [Not invited]
    Chietsugu Katoh, Keigo Ishiyama, Kenji Hirata
    The 80Th Annual Meeting of the Japanese Radiological Society  2021/04
  • Clinical molecular imaging and image analysis  [Invited]
    Chietsugu Katoh
    Summer School for Medical Physics, Global Center for Biomedical Science and Engineering;Hokkaido University, Sapporo  2021/02
  • Evaluation of Super-Resolution Convolutional Neural Network using High resolution PET  [Not invited]
    Chietsugu Katoh, Hiroki Endo
    The 60th Annual Science Meeting of Japanese Society of Nuclear Medicine  2020/11
  • PET画像におけるDeep learningとその複合技術を用いた検出精度の検討  [Not invited]
    河上壮志, 杉森博行, 平田健司, 孫田惠一, 加藤千恵次
    第40回日本核医学技術学会総会学術大会、神戸  2020/11
  • 人工知能による結節性多発動脈炎と皮膚動脈炎の皮膚生検画像の鑑別  [Not invited]
    新海隼人, 石津明洋, 加藤千恵次
    第25回日本血管病理研究会 Web会議 厚労省「難治性血管炎班」臨床病理分科会  2020/11
  • Classification of images of Arteritis Using CNN  [Not invited]
    新海隼人, 石津明洋, 加藤千恵次
    日本生体医工学会 第59回北海道支部大会、札幌  2020/10
  • PET画像におけるSuper Resolution Convolutional Neural Network（SRCNN）の開発と検討  [Not invited]
    遠藤大輝, 加藤千恵次
    第59回日本生体医工学会北海道支部大会、札幌  2020/10
  • Evaluation of Automatic Detection of Abnormal Uptake by Deep Learning and Combination Technique in FDG–PET Images  [Not invited]
    Masashi Kawakami, Hiroyuki Sugimori, Kenji Hirata, Chietsugu Katoh
    Society of Nuclear Medicine and Molecular imaging (SNMMI) 2020 Annual Meeting, Web meeting, USA  2020/07
  • Strategy to acquire high resolution PET images with Super-Resolution Convolutional Neural Network (SRCNN)  [Not invited]
    Chietsugu Katoh, Endo Daiki, Keiichi Magota, Osamu Manabe, Kenji Hirata
    Society of Nuclear Medicine and Molecular imaging (SNMMI) 2020 Annual Meeting, Web meeting, USA  2020/07
  • ECG-gated myocardial 15O-H2O PET yielded higher and robuster estimation of flow reserve in ischemic myocardium after revascularization than non-gated PET  [Not invited]
    KATOH CHIETSUGU
    第79回日本医学放射線学会総会、Web開催  2020/05
  • Estimation of PTF in ischemic myocardium after revascularization with ECGgated 15O-H2O PET  [Not invited]
    KATOH CHIETSUGU
    第59回日本核医学会学術総会、松山  2019/11
  • 15O-H2O PET検査による心筋血流測定における心電図同期収集の試み  [Not invited]
    小泉ひなの, 加藤 千恵次
    第39回日本核医学技術学会総会学術大会、松山  2019/11
  • シングルボードコンピュータを用いた独立型コンピュータ支援診断システムの開発  [Not invited]
    石山敬悟, 加藤 千恵次
    第39回日本核医学技術学会総会学術大会、松山  2019/11
  • 深層学習を用いたFDG PET/CTに対する患者誤認事故防止システムの検討  [Not invited]
    杉山泰樹, 川内敬介, 加藤千恵次
    第39回日本核医学技術学会総会学術大会、松山  2019/11
  • CNNを用いた悪性リンパ腫のLugano分類におけるコンピュータ支援診断システムの開発  [Not invited]
    松倉吉彦, 渡邊史郎, 平田健司, 加藤千恵次
    第39回日本核医学技術学会総会学術大会、松山  2019/11
  • Deep learningを用いたPET画像における病変や生理的集積の自動検出精度の検討  [Not invited]
    河上壮志, 平田健司, 杉森博行, 加藤千恵次
    第39回日本核医学技術学会総会学術大会、松山  2019/11
  • 小型シングルボードコンピュータによる完全独立型コンピュータ診断支援システムの開発  [Not invited]
    石山敬悟, 加藤千恵次
    日本生体医工学会第58回北海道支部大会、札幌  2019/10
  • 人工知能は結節性多発動脈炎と皮膚動脈炎の皮膚生検組織所見を区別した  [Not invited]
    新海隼人, 加藤千恵次, 石津明洋
    第52回北海道病理談話会、旭川  2019/10
  • Strategy to improve the detectability of Myocardial Flow Reserve in the ischemic myocardial lesion after revascularization using ECG-gated dynamic myocardial PET with 15O-H2O: Comparison with non-gated PET  [Not invited]
    CHIETSUGU KATOH
    2019 Society of Nuclear Medicine and Molecular imaging (SNMMI) Annual Meeting, Anaheim, California, USA  2019/06
  • Development of a CNN-based computer-aided diagnosis system for Lugano classification of malignant lymphoma by using whole-body FDG PET-CT  [Not invited]
    MATSUKURA YOSHIHIKO, HIRATA KENJI, KATOH CHIETSUGU
    2019 Society of Nuclear Medicine and Molecular imaging (SNMMI) Annual Meeting, Anaheim, California, USA  2019/06
  • ECG-gated dynamic myocardial PET with 15O-H2O estimated higher perfusable tissue fraction in the ischemic myocardial lesions after revascularization: compared with conventional non-gated PET  [Not invited]
    CHIETSUGU KATOH
    2019 Society of Nuclear Medicine and Molecular imaging (SNMMI) Annual Meeting, Anaheim, California, USA  2019/06
  • Improvement of Estimation of Coronary Flow Reserve in the Ischemic Myocardial Lesion with ECG-gated Dynamic Myocardial PET with 15O-H2O: Comparison with Conventional Non-gated PET  [Not invited]
    CHIETSUGU KATOH
    The 78th Annual Meeting of the Japan Radiological Society  2019/04
  • CT image reconstruntion using Deep learning: Strategy for reducing metal artifact  [Not invited]
    YUJI TANAKA, KENJI HIRATA, CHIETSUGU KATOH
    The 75th Annual Meeting of the Japanese Society of Radiological Technology (JSRT)  2019/04
  • Development of Computer-aided Diagnosis System for Staging of Malignant Lymphoma  [Not invited]
    YOSHIHIKO MATSUKURA, KENJI HIRATA, CHIETSUGU KATOH
    The 75th Annual Meeting of the Japanese Society of Radiological Technology (JSRT)  2019/04
  • 悪性リンパ腫のステージングの自動診断支援ソフトウェアの開発  [Not invited]
    松倉吉彦, 平田健司, 加藤千恵次
    第38回日本核医学技術学会総会学術大会 沖縄  2018/11
  • Estimation of perfusable tissue fraction using ECG-gated dynamic heart PET with 15O-H2O  [Not invited]
    KATOH CHIETSUGU
    The 58th. Annual Meeting of the Japanese Society of Nuclear Medicine  2018/11
  • 15O標識水PETを用いた冠血行再建治療前後における局所冠血流予備能の定量評価  [Not invited]
    相川忠夫, 納谷昌直, 真鍋治, 孫田惠一, 小梁川和宏, 浅川直也, 真鍋徳子, 志賀哲, 加藤千恵次, 玉木長良, 安斉俊久
    第58回日本核医学会学術総会、沖縄  2018/11
  • 15O-水 心筋血流PETにおける Monte Carlo scaling 複合型SSS散乱補正の検討  [Not invited]
    孫田惠一, 志賀哲, 真鍋治, 納谷昌直, 相川忠夫, 新山大樹, 平田健司, 加藤千恵次, 藤田勝久, 玉木長良
    第38回日本核医学技術学会総会学術大会  2018/11
  • Detection of Diastolic Myocardial Images in ECG-gated PET and Positioning the myocardial ROI using Deep Learning Algorythm  [Not invited]
    KATO SHINYA, KAWAUCHI KEISUKE, KATOH CHIETSUGU
    The 38Th Annual Meeting of the Japanese Society of Nuclear Medicine Technology  2018/11
  • Detection of Edges of Tumors using CNN Algorithm in 11C-Methionine PET images  [Not invited]
    ICHIKAWA SEIYA, HIRATA KENJI, KAWAUCHI KEISUKE, KATOH CHIETSUGU
    The 38Th Annual Meeting of the Japanese Society of Nuclear Medicine Technology  2018/11
  • Development of Computer Aided Diagnostic System with CNN in FDGPET/CT images  [Not invited]
    KAWAUCI KEISUKE, HIRATA KENJI, ICHIKAWA SEIYA, KATOH CHIETSUGU
    The 38Th Annual Meeting of the Japanese Society of Nuclear Medicine Technology  2018/11
  • FDG PET/CTに対する深層学習を用いた患者誤認事故防止システムの検討  [Not invited]
    杉山泰樹, 平田健司, 川内敬介, 市川晟也, 加藤千恵次
    第38回日本核医学技術学会総会学術大会  2018/11
  • Segmentation of PET images using Deep Learning  [Not invited]
    TANAKA YUJI
    第38回日本核医学技術学会総会学術大会 沖縄  2018/11
  • CT image Reconstraction using Deep Learning Algorythm and strategy to Decrease Metal Artifacts  [Not invited]
    TANAKA YUJI, HIRATA KENJI, KATOH CHIETSUGU, KAWAUCHI KEISUKE
    The 57th Hokkaido Branch of Japanese Society of Medical and Biological Engineering  2018/10
  • FDG PET/CTに対する深層学習を用いた患者誤認事故防止システムの検討  [Not invited]
    杉山泰樹, 川内敬介, 平田健司, 市川晟也, 加藤千恵次
    第57回日本生体医工学会北海道支部大会 札幌  2018/10
  • Error Detection System using Deep Learning Algorythm in FDGPET/CT study  [Not invited]
    KAWAUCHI KEISUKE, HIRATA KENJI, ICHIKAWA SEIYA, KATOH CHIETSUGU
    Japanese Society of Artificial Intelligence in Medical Imaging  2018/10
  • Development of automatic extraction system for brain tumor ROI of 11C-methionine PET  [Not invited]
    ICHIKAWA SEIYA, HIRATA KENJI, KATOH CHIETSUGU
    Society of Nuclear medicine and Imaging (SNMMI) 2018 Annual Meeting, Philadelphia, USA  2018/06
  • Strategy to improve the detectability of CFR in the ischemic myocardial lesion with ECG-gated dynamic myocardial PET with 15O-H2O: Comparison with conventional non-gated PET  [Not invited]
    KATOH CHIETSUGU
    Society of Nuclear medicine and Imaging (SNMMI) 2018 Annual Meeting, Pennsylvania, USA  2018/06
  • Development of a system to cope with patient misunderstanding in FDG‐PET examination using convolutional neural network  [Not invited]
    KAWAUCHI KEISUKE, HIRATA KENJI, KATOH CHIETSUGU
    Society of Nuclear medicine and Imaging (SNMMI) 2018 Annual Meeting, Philadelphia, USA  2018/06
  • Comparison of electrocardiogram synchronization and asynchronization in myocardial blood flow measurement with 15O-H2O PET  [Not invited]
    Shinya Kato, Keisuke Kawauchi, Chietsugu Katoh
    Society of Nuclear medicine and Imaging (SNMMI) 2018 Annual Meeting, Philadelphia, USA  2018/06
  • Strategy to develop convolutional neural network-based classifier for diagnosis of whole-body FDG PET images  [Not invited]
    KAWAUCHI KEISUKE, HIRATA KENJI, KATOH CHIETSUGU
    Society of Nuclear medicine and Imaging (SNMMI) 2018 Annual Meeting, Philadelphia, USA  2018/06
  • ECG-gated dynamic myocardial PET with 15O-H2O estimated lower perfusable tissue fraction in the ischemic myocardial lesions compared with conventional non-gated PET  [Not invited]
    KATOH CHIETSUGU
    Society of Nuclear medicine and Imaging (SNMMI) 2018 Annual Meeting, Pennsylvania, USA  2018/06
  • Discrimination of Brain Tumor of 11C Methionine PET Image by Deep Learning  [Not invited]
    ICHIKAWA SEIYA, HIRATA KENJI, KATOH CHIETSUGU
    The 74th Annual Meeting of the Japanese Society of Radiological Technology (JSRT)  2018/04
  • Comparison of electrocardiogram synchronization and asynchronization in myocardial blood flow measurement with 15O-H2O PET  [Not invited]
    KATO SHINNYA, KATOH CHIETSUGU
    The 74th Annual Meeting of the Japanese Society of Radiological Technology (JSRT)  2018/04
  • Investigation of usefulness of deep learning in FDG-PET image analysis  [Not invited]
    KAWAUCHI KEISUKE, HIRATA KENJI, KATOH CHIETSUGU
    The 74th Annual Meeting of the Japanese Society of Radiological Technology (JSRT)  2018/04
  • Quantitative evaluation of ischemic myocardium using dynamic CT: Comparison with 15O-H2O PET  [Not invited]
    KATOH CHIETSUGU
    The77th. Annual Meeting of the Japan Radiological Society  2018/04
  • 15O-H2O心筋PETによる虚血心筋病変の冠血管血流予備能定量の改良  [Not invited]
    加藤 千恵次
    第57回日本核医学会学術総会、横浜  2017/10
  • Estimation of damaged myocardial lesion using multi-detector CT as compared with 15O-H2O PET  [Not invited]
    KATOH CHIETSUGU
    The 2017 Society of Nuclear Medicine and Molecular Imaging Annual Meeting (Denver, USA)  2017/06
  • Strategy to detect ischemic myocardial lesion with 15O-H2O PET using a weighted function : Evaluation with Akaike information criterion  [Not invited]
    KATOH CHIETSUGU
    The 2017 Society of Nuclear Medicine and Molecular Imaging Annual Meeting (Denver, USA)  2017/06
  • 15O-H2O心筋PETにおける虚血病変検出能の改善：AIC法による評価  [Not invited]
    加藤 千恵次
    第76回日本医学放射線学会総会（横浜）  2017/04
  • Application of the Medical Field of Inexpensive Personal 3D printers; Modeling of Coronary Arteries and Calcified Lesions  [Not invited]
    KAWAUCHI KEISUKE, KATOH CHIETSUGU
    The 73rd Annual Meeting of the Japanese Society of Radiological Technology  2017/04
  • Iterative factor analysis: Strategy for estimating input function in dynamic 18F-FDG brain PET  [Not invited]
    KATOH CHIETSUGU
    Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2016 Annual Meeting (San Diego, USA)  2016/06
  • 繰返し因子分析法の開発：ダイナミックFDG脳PETにおける動脈血流放射能曲線抽出への応用  [Not invited]
    加藤 千恵次
    第75回日本医学放射線学会総会  2016/04
  • 320列CTを用いた心電図同期ダイナミック撮像による心筋血流定量と被曝量軽減の試み  [Not invited]
    加藤 千恵次
    第54回日本生体医工学会北海道支部大会  2015/10
  • Estimation of myocardial blood flow using multi-detector CT as compared with 15O-H2O PET: Strategy for reducing radiation dose in myocardial CT study  [Not invited]
    KATOH CHIETSUGU
    Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2015 Annual Meeting (Baltimore, USA)  2015/06
  • Circulality of left ventricle correlates with right ventricular function and pulmonary hemodynamics in patients with pulmonary hypertension using 11C-acetate PET  [Not invited]
    KATOH CHIETSUGU
    第73回日本医学放射線学会  2014/04
  • Errors in attenuation correction with ECG-gated myocardial PET/CT images: Evaluation with phantom study  [Not invited]
    KATOH CHIETSUGU
    第72回日本医学放射線学会総会（横浜）  2013/04
  • The algorithm to quantify the myocardial sympathetic nerve function with 11C-Hydroxyephedrine （HED） and 3D-PET  [Not invited]
    KATOH CHIETSUGU
    The 2012 Society of Nuclear Medicine and Molecular Imaging Annual Meeting (Miami, USA)  2012/06
  • Quantification of Myocardial Blood Flow with 11C-Acetate PET dynamic image: Comparison with 15O-H2O PET  [Not invited]
    KATOH CHIETSUGU
    Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2012 Annual Meeting (Miami, USA)  2012/06
  • The algorithm to quantify the myocardial sympathetic nerve function with 11C -Hydroxyephedrine and 3D-PET  [Not invited]
    KATOH CHIETSUGU
    The 71st Annual Meeting of the Japan Radiological Society  2012/04
  • 3D収集 82Rb心筋PET における 心筋血流定量の安定化 ： 荷重関数を利用した血液成分補正法  [Not invited]
    加藤 千恵次
    第50回日本核医学会学術総会  2011/11
  • 11C-HED心筋PETにおける 交感神経機能定量プログラムの開発  [Not invited]
    加藤 千恵次
    第 51 回日本核医学会学術総会 （つくば市）  2011/10
  • A new algorithm to suppress spillover fraction for 11C-Hydroxyephedrine myocardial 3D PET: Non-uniform least squared method with a weighted function using blood time-activity curve  [Not invited]
    KATOH CHIETSUGU
    The 2011 Society of Nuclear Medicine and Molecular Imaging Annual Meeting (San Antonio, USA)  2011/06
  • Development of a new a protocol to evaluate the pancreatic sympathetic nervous system using 11C-HED with 3D PET  [Not invited]
    KATOH CHIETSUGU
    The 2011 Society of Nuclear Medicine and Molecular Imaging Annual Meeting (San Antonio, USA)  2011/06
  • 11C-酢酸PETでの肺高血圧症の定量的診断： 右室心筋酸素代謝自動定量プログラム開発  [Not invited]
    加藤 千恵次
    第70回日本医学放射線学会総会（横浜）  2011/04
  • A new algorithm to suppress spillover fraction from the blood radioactivity for 82Rb myocardial 3D PET: Non-uniform least squared method with a weighted function using blood time-activity curve  [Not invited]
    KATOH CHIETSUGU
    Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2010 Annual Meeting (Salt Lake City, USA)  2010/06
  • ルビジウム82心筋PETにおける３次元収集による局所心筋血流定量法の開発  [Not invited]
    加藤 千恵次
    第69回日本医学放射線学会総会（横浜）  2010/04
  • New Quantification Algorithm of Regional Myocardial Blood Flow with 82Rubidium PET  [Not invited]
    KATOH CHIETSUGU
    Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2008 Annual Meeting ( USA)  2008/06
  • 15O標識ガスPETによる脳血流定量における脳血液量の影響：定常吸入法とダイナミック法の比較  [Not invited]
    加藤 千恵次
    第66回日本医学放射線学会総会（横浜）  2007/04
  • Automated Algorithm for Quantification of left ventricular ejection fraction with 15O-Water and 15O-CO using ECG-gated PET  [Not invited]
    KATOH CHIETSUGU
    Society of Nuclear Medicine 53rd Annual Meeting (San Diego, USA)  2006/06

MISC

Industrial Property Rights

  • 特願北海道大学職務発明:Hokkaido Quantitative Tool (HOQUTO): Heart Rubidium 2 dimensional myocardial blood flow  2012年/12/07
    KATOH CHIETSUGU
  • 医療用画像処理システム
    2007-043613

Awards & Honors

  • 2018/06 Seminar of Nuclear Medicine and Molecular Imaging Annual Meeting (USA, Philadelphia) International Best Abstract Award
     
    受賞者: KATOH CHIETSUGU
  • 2012/09 American Society of Nuclear Cardiology Award for the Best Technical Imaging Paper
     
    受賞者: KATOH CHIETSUGU
  • 1994/09 Japanese Sciety of Nuclear Medicine The 34th.JSNM Presentation award
     
    受賞者: KATOH CHIETSUGU

Research Grants & Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2023/04 -2026/03 
    Author : 江本 美穂, 加藤 千恵次
  • Japan Society for the Promotion of Science：Research Fee Base (C)
    Date (from‐to) : 2022/04 -2025/03 
    Author : Chietsugu Katoh
  • 半導体検出器ＰＥＴによる心電図同期ダイナミック心筋ＰＥＴ検査の開発
    Japan Society for the Promotion of Science：Development of ECG-gated dynamic myocardial PET using semiconductor PET system
    Date (from‐to) : 2019/04 -2022/03 
    Author : KATOH CHIETSUGU
  • アポトーシス標的アイソトープ治療による動脈硬化不安定プラーク制御法の開発
    日本学術振興会：科学研究費 基盤(B)
    Date (from‐to) : 2018/04 -2021/03 
    Author : 吉永恵一郎
  • 日本学術振興会：科学研究費 基盤（C)
    Date (from‐to) : 2015/04 -2018/03 
    Author : KATOH CHIETSUGU
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2014/04 -2017/03 
    Author : Oyama-Manabe Noriko, Kikuchi Yasuka
     
    By using low-dose dynamic CTP with 320-row multi-detector CT (MDCT), we have developed a comprehensive method to estimate myocardial blood flow derived from CT (MBFCT) and coronary flow reserve derived from CT (CFRCT), validated with 15O-water PET. We also hypothesized that the severity of CAD might inversely correlate with the MBFCT and CFRCT. Quantitative per-patient and per-vessel CFRCT and hyperemic MBFCT assessed with 320-row MDCT, showed a moderately good diagnostic performance for identifying patients with obstructive CAD in a clinical setting. CFRCT and MBFCT are clinically useful for evaluating CAD and may contribute to pathophysiological investigations of CAD.
  • 上腕動脈血管機能計測による動脈硬化症早期診断のための生理的機能診断システム構築
    科学研究費補助金：挑戦的萌芽研究
    Date (from‐to) : 2012/04 -2015/03 
    Author : 吉永恵一郎
  • ３テスラMRIを用いた心筋血流量および梗塞病変の定量検出
    日本学術振興会：科学研究費 基盤（C)
    Date (from‐to) : 2012/04 -2015/03 
    Author : 加藤千恵次
  • 呼吸器疾患に伴う心血管疾患の検出、治療戦略構築へのポジトロン断層撮影法の導入
    科学研究費補助金：基盤研究(B)
    Date (from‐to) : 2011/04 -2014/03 
    Author : 吉永恵一郎
  • 心臓再同期療法における酢酸、水PETを用いた心筋局所酸素代謝、心筋血流の評価
    科学研究費補助金：基盤研究(C)
    Date (from‐to) : 2010/04 -2013/03 
    Author : 千葉 知
  • 日本学術振興会：科学研究費 基盤（Ｃ）
    Date (from‐to) : 2008/04 -2010/03 
    Author : 加藤千恵次
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2008 -2010 
    Author : SHIGA Tohru, IKOMA Katsunori, TERAE Satoshi, KATOH Chietsugu, KUGE Yuji
     
    One of the aims was to analyze the sequential and spatial change of benzodiazepine receptor density, metabolism, neuronal integrity using molecular imaging such as SPECT and PET. To clarify the sequential change, we investigate the reconstruction and analyzing method for animal C-11 flumazenil using animal PET/SPECT/CT. We developed a new method for analyzing binding potential of C-11 flumazenil using rat model. Another aim was to investigate the relationship between effect of rehabilitation and neuronal integrity in patients with brain injury. First we studied the relationship between C-11 flumazenil PET findings and I-123 Iomazenil SPECT findings. Our study indicated that although IMZ SPECT has slightly lower contrast than FMZ PET, IMZ SPECT could detect loss of neuronal integrity as almost same as FMZ PET. Second, we investigate the relationship among metabolic change, loss of neuronal integrity and effect of rehabilitation. However, we could not find the relationship among those parameters.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2007 -2009 
    Author : KUBO Naoki, KATOH Chietsugu, KANEKO Jyunichi, KIMURA Ayaka, NAKAMARU Hiroshi
     
    We have investigated a new noninvasive blood-radioactivity monitor. The monitor estimates the input functions for quantitative PET by sequentially measuring the radioactivity of the radial artery. Thus, we indicated that a PET scan is more comfortable for patients.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2005 -2009 
    Author : SHIRATO Hiroki, KANEKO Junichi, NISHIYAMA Syusuke, KATOH Chietsugu, AOYAMA Hidefumi, SEKI Koh-ichi, ONIMARU Rikiya, NISHIOKA Takeshi, MORITA Koichi, DATE Hiroyuki, TAKADA Eiji, TOMIOKA Satoshi, KUDO Kohsude, ONODERA Yuya, KAMISHIMA Tamotsu, ONIMARU Rikiya, SHIMIZU Shinichi, SAKUHARA Yusuke, OYAMA Noriko, ABO Daisuke, TAGUCHI Hiroshi
     
    We developed a four-dimensional (4-D, space and time) focal positron emission localizer, FPEL, using two sets of BGO scintillators, photo-electric multiplier, and collimators. A narrow (5-mm in diameter) 45-MeV electron beam was controlled to irradiate a target with an accuracy of 0.1mm in 4D coordinates automatically if the amount of positron emitters at the target exceeds the threshold. A mouse model was established to irradiate the tumor in which FDG is accumulated. Using the FPEL, 45-MeV electron beam hit the tumor in mice which move in front of the beam exit with the amplitude resembling human respiration. Tumor without fiducial gold marker disappeared within a week after the irradiation. Basis for 4D stereotacic radiotherapy was established successfully.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2006 -2007 
    Author : TERAE Satoshi, YAMAMOTO Toru, KATOH Chietsugu, KURODA Satoshi, KUDO Kohsuke
     
    Using susceptibility-weighted imaging (SWI) of MRI (magnetic resonance imaging), we tried to develop a method to measure regional oxygen consumption of the brain. We evaluated local inhomogeneity of the magnetic field caused by deoxyhemoglobin (deoxyHb) in the cerebral vein using the phase information of SWI. We found that the local inhomogeneity observed by SWI is strongly affected by an angle between the longitudinal axis of the vein and the direction of the static magnetic field of the MRI unit. Therefore, the angle has to be incorporated to calculate local deoxyHb concentration of the vein. In normal volunteers, the phase shift increased under hyperventilation and it decreased under breath hold. Changes in oxygen saturation of the veins and in cerebral blood flow, that were calculated by using the difference in phase shift, showed the same results. This indicates that we can measure deoxyHb concentration of the cerebral veins by SWI if we can establish a reference of relationship between the amount of phase shift and deoxyHb concentration in the vein. In a patient with acute cerebral infarct, the largest local phase shift was observed in the infracted area. The phase shift was the largest immediately after the onset, and it decreased gradually during the first 20 days. In contrast, in another patient with chronically impaired blood flow and increased oxygen extraction fraction (OEF) in left anterior and middle cerebral artery territory that was caused by left internal carotid artery occlusion, there was no difference in the phase shift between the ischemic area and the contralateral healthy area. These results imply that SWI can detect increased deoxyHb in the veins of acute ischemic area, but cannot detect increased OEF in chronic phase.
  • PETを用いた心筋β受容体機能のインビボでの定量的解析に関する研究
    日本学術振興会：科学研究費 萌芽研究
    Date (from‐to) : 2004/04 -2005/03 
    Author : 加藤千恵次
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2003 -2005 
    Author : 久保 直樹, 加藤 千恵次, 玉木 長良
     
    本年度は矩形ファントムの作製と実験結果の解析を完了させた.矩形ファントムについてであるが前年度におこなったカバーグラスにスペーサを置いたものとはせずにMicroscope Cover Slips(22×22mm,プラスチック製,Fisher Scientific Co.)の四方を,別の4枚のMicroscope Cover Slipsで囲んで固定することで作製した. 対照実験として直径3mm高さ3mmの微小円柱^<99m>Tc線源を,精密微動ステージ(明立精機社製)に乗せコリメータに密着して撮像した.γカメラはデジラド社2020tcであった.(1)x方向y方向同時にセンタアライメント,(2)x方向にシフトアライメント,(3)y方向にシフトアライメント,(4)x方向y方向同時にシフトアライメントの計4種類の画像を,それぞれ2分間ずつ収集した.次に今回作製した矩形ファントムを微小円柱線源と同様の配置で3分間収集した.撮像されたファントム画像をVGC-V202RBコンピュータシステムに転送しx方向の差分およびy方向の差分を施した.差分した画像においてファントムの頂点にあたる部分を点応答関数とした. 微小円柱線源において直径3.0mmの線源が6.5mmと観察される場合があった.また円形であるにも関わらず線源の形が変化してしまい,x方向の長さとy方向の長さが大きく異なる場合があることも観察された.一方,今回の矩形ラァントムを使用することで,2次元的なセンターおよびシフトアライメントを考慮した空間分解能を評価することが可能であった.そしてこの評価結果で,先程示された微小円柱線源の形状の変化を説明することができた.またこのように矩形ファントムの頂点を微分して測定した場合,理想的な点線源になり,このことで従来の球線源とは違い,測定結果が線源の大きさの影響を受けないと考えられた.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2003 -2005 
    Author : TAMAKI Nagara, MORITA Koichi, KATOH Chietsugu
     
    Assessment of coronary atherosclerosis plays a major role for dearly detection and management of patients with coronary artery disease. Positron emission tomography (PET) using O-15 labeled water permits quantitative assessment of myocardial blood flow, and therefore, this is valuable means for measurement of myocardial flow reserve and coronary endothelial function noninvasively. In the study of patients suspected with coronary artery disease, myocardial flow reserve was reduced not only in the areas with coronary stenosis but also in the remote areas in the patients having coronary risk factors. Multivariate analysis indicated that smoking and diabetes were the only independent variables which reduced myocardial flow reserve. In addition, coronary endothelial dysfunction was identified in patients with young healthy smokers and remote stage of Kawasaki disease. Moreover, such coronary endothelial dysfunction was reversible after smoking cessation. These data indicate that O-15 labeled water PET is feasible for early detection and management of coronary atherosclerosis in clinical setting.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2001 -2003 
    Author : KUBO Naoki, TAMAKI Nagara, KATOH Chietsugu, MOTOMURA Nobutoku
     
    We have designed novel pinhole and converging collimators for cone-beam SPECT of small objects. Particularly, these collimators were designed to cope with ultrahigh energy gamma photons. Cone-beam collimators, including pinhole and converging collimators, magnify an acquired image using gamma cameras. Consequently, spatial resolution of the image is improved. For the pinhole collimator, the diameter of the knife-edge pinhole aperture was 1.3 mm and the acceptance angle was 1゜. The thickness of the lead shielding was 30 mm. In SPECT experiments, spatial resolution, expressed as full-width-at-half maximum (FWHM), was 2.4±0.4 and 3.2±0.3 mm for Tc-99m and F-18 SPECT, respectively. In calculated simulations, as the pinhole-object distance decreased, geometric sensitivity geometrically increased. However, as the pinhole-object distance decreased, field-of-view decreased linearly. SPECT of a rat using Tc-99m and F-l8 enabled successful in vivo visualization of the myocardium. The converging collimator had a focal length of 200 mm, a hole length of 110 mm at the center and a hole diameter of 1.5 mm. Magnification was 1.9 times at a source-to-collimator distance of 10 mm. Planar spatial resolution was 1.7±0.2 mm and 2.8±0.8 mm (FWHM) for Tc-99m and F-18, respectively. A small myocardial phantom was clearly visualized by both Tc-99m and F-18 SPECT. Thus, we have demonstrated that high-resolution SPECT images can be acquired at ultra-high energy using our cone-beam collimators. Moreover, the most remarkable feature of our converging collimators is applicability to conventional rotating gamma camera SPECT systems. In addition, we have evaluated the spatial resolution of a commercial converging collimator which had a very short focal length (200 mm). The spatial resolution of the converging collimator was superior to that of the parallel-hole collimator. Thyroid scintigraphy using the commercial converging collimator better visualized cold lesions than the parallel-hole collimator.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2000 -2001 
    Author : TERAE Satoshi, MIYASAKA Kazuo, KATO Chietsugu
     
    To assess accuracy of dynamic, contrast-enhanced CT perfusion imaging, we compared cerebral blood flow (CBF) measured by the CT perfusion imaging (CT-CBF) with CBF by positron emission tomography (PET-CBF) in five normal volunteers and four patients in chronic stage of ischemic cerebral diseases. For CT per fusion, 370 or 350 mgI/ml of contrast material was injected via a superficial vein using power injector at a rate of 5 ml/sec. Single slice volume (8 mm x 4-collimation) was scanned for 30 - 60 seconds with 80 kVp and 1 second/rotation. We programmed a deconvolution method to analyze the CT perfusion data on personal computer. Arterial input function was determined by measuring time-density curve at the distal end of the internal carotid artery. We also developed a software to co-register PET data to CT images. On visual impression, apparently higher CBF along the cerebral surface was seen on CT-CBF maps, as compared to PET-CBF maps. However, contrast between gray and white matter, and contrast between the ischemic area and normal brain on CT-CBF were similar to those on PET-CBF. After exclusion of pixels that included relatively large vessels from CT-CBF, calculated CBF values by perfusion CT were almost identical to those by PET for the entire slice. The difference was +3 to +12% for the affected hemisphere, and -3 to +9% for the contralateral hemisphere in the patients. Linear regression analysis of CBF values between the CT-CBF and the PET-CBF maps showed relatively good correlation with a correlation coefficient (γ) varying in rang from 0.62 to 0.72. Dynamic, contrast-enhanced CT perfusion imaging is a promising technique for the accurate measurement of cerebral blood perfusion, and will provide valuable information on the severity of ischemic lesions.

Educational Activities

Teaching Experience

  • physiologyphysiology School of Medicine, Hokkaido University, Department of Health Sciences
  • Research and Development of Medical Devices
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 医療機器、医学物理、画像診断、機能診断、放射線治療、粒子線治療
  • Basic Physics for Diagnostic Radiology and Nuclear Medicine
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 放射線診断、画像診断、核医学、放射線撮像装置基礎原理
  • Advanced Physics for Diagnostic Radiology and Nuclear Medicine
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 放射線診断、画像診断、核医学、放射線撮像装置の応用技術
  • General Research on Biomedical Science and Engineering I
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 放射線診断、画像処理、プログラミング
  • General Research on Biomedical Science and Engineering II
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 放射線診断、画像処理、プログラミング
  • Inter-Graduate School Classes(General Subject):Natural and Applied Sciences
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : radiation treatment, particle therapy, medical physics, radiobiology, radiomics
  • Inter-Graduate School Classes(General Subject):Natural and Applied Sciences
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : Cancer imaging, Deep learning for imaging, Cancer biology, Radiotherapy for Cancer cure, Proton Beam Therapy, Theragnostics
  • Molecular Biomedical Science and Engineering School
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : Cancer imaging, Deep learning for imaging, Cancer biology, Radiotherapy for Cancer cure, Proton Beam Therapy, Theragnostics
  • Functional Imaging for Diagnosis in Biomedical Science and Engineering
    開講年度 : 2021
    課程区分 : 修士課程
    開講学部 : 医理工学院
    キーワード : 画像診断 機能画像 PET シンチグラフィ 放射性医薬品 MRI CT
  • Advanced Research on Biomedical Science and Engineering I
    開講年度 : 2021
    課程区分 : 博士後期課程
    開講学部 : 医理工学院
    キーワード : 画像解析、医用画像、病理組織像、超音波画像、核医学画像、PET画像、CT画像、MRI画像、プログラミング、C言語、 フーリエ解析、コンパートメントモデル解析、パターン認識、最小二乗法
  • Advanced Research on Biomedical Science and Engineering II
    開講年度 : 2021
    課程区分 : 博士後期課程
    開講学部 : 医理工学院
    キーワード : 放射線診断、画像処理、プログラミング
  • Medical Imaging Ⅰ
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 超音波検査、消化器領域、乳腺･甲状腺領域、循環器領域、産婦人科領域、MRI
  • Introduction to Medical Engineering
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : ME（Medical Engineering）、医用機器、オペアンプ回路、インピーダンス、電撃防止対策
  • Medical Imaging EquipmentⅡ
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : CT、 断層画像、眼底検査、超音波検査
  • Nuclear Medicine Technology
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 核医学、RI、インビボ検査、PET、SPECT、RIA
  • Laboratory Exercise in Nuclear Medicine
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 核医学、RI、SPECT、PET、画像処理
  • Introduction to Nuclear Medicine
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 放射性同位元素（RI）、核医学、放射線、情報科学、医用工学
  • Introduction to Biomedical Measurements and Instrumentation
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 人体の情報を測定する医用機器の種類と原理、および診断法の概要を学ぶ。 ME（Medical Engineering；医用工学）の基礎を学ぶ。
  • Practice in Medical Engineering
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 医用工学（ME）、電子回路、デジタル（論理）回路、ME機器管理
  • Radiological Regulations
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 医療法、診療放射線技師法 放射線障害防止法 電離放射線障害防止規則 国際放射線防護委員会（ＩＣＲＰ）勧告 放射線防護
  • Laboratory Exercise in Radiochemistry
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 放射線被曝、放射腺防護、放射線管理
  • Introduction to Nuclear Medicine
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 放射性同位元素、核医学検査、PET、SPECT
  • Introduction to Nuclear Medicine Equipment
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 医用画像処理、フィルタ処理、フーリエ変換、重畳積分、断層画像再構成法
  • Physiology
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 生理学
  • Laboratory Exercise in Radiation Protection
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 放射線被曝、放射腺防護、放射線管理
  • Nuclear Medicine
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 画像診断　PET　SPECT　IVR　画像定量化　アイソトープ治療
  • Introduction to Health Sciences and Medicine
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 医学部
    キーワード : 医学、医療、保健、福祉、医療制度、チーム医療、早期臨床体験実習

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