顔写真

シダハラ ミホ
志田原 美保
Miho Shidahara
所属
大学院工学研究科 量子エネルギー工学専攻 粒子ビーム工学講座(応用量子医工学分野)
職名
准教授
学位
  • 博士(工学)(東北大学)

  • 修士(工学)(東北大学)

経歴 8

  • 2022年10月 ~ 継続中
    東北大学 工学研究科 准教授

  • 2018年4月 ~ 2022年9月
    東北大学 工学研究科 講師

  • 2010年4月 ~ 2018年3月
    東北大学 医学系研究科 講師

  • 2006年1月 ~ 2010年3月
    放射線医学総合研究所 研究員

  • 2003年1月 ~ 2005年12月
    日本学術振興会 特別研究員PD

  • 2002年4月 ~ 2002年12月
    国立長寿医療研究センター研究所 流動研究員

  • 2000年1月 ~ 2001年8月
    国立循環器病センター研究所 放射線医学研究部 研修生

  • 1999年2月 ~ 2000年1月
    秋田県立脳血流血管研究所 放射線医学部 研修生

︎全件表示 ︎最初の5件までを表示

学歴 2

  • 東北大学 工学研究科 量子エネルギー工学専攻

    1997年4月 ~ 2002年3月

  • 東北大学 工学部 量子エネルギー工学科

    1993年4月 ~ 1997年3月

委員歴 13

  • 日本学術会議 連携会員

    2023年10月 ~ 継続中

  • 日本核医学会北日本地方会 世話人

    2023年7月 ~ 継続中

  • 公益社団法人 日本アイソトープ協会 RADIOISOTOPES誌 編集委員

    2023年4月 ~ 継続中

  • Frontiers in Nuclear Medicine Associate Editor

    2023年3月 ~ 継続中

  • IEEE Sendai Women in Engineering Chair

    2023年1月 ~ 継続中

  • 日本原子力学会東北支部 幹事

    2018年5月 ~ 継続中

  • 日本核医学会 核医学理工分科会 世話人

    2016年12月 ~ 継続中

  • 日本放射線技術学会 Radiological Physics and Technology Guest Associate editor

    2015年4月 ~ 継続中

  • 日本核医学会 ダイバーシティー推進準備委員会 委員

    2022年3月 ~ 2023年10月

  • IEEE Sendai Women in Engineering Secretary and Treasurer

    2021年1月 ~ 2022年12月

  • 日本核医学会 Annals of Nuclear Medicine 編集委員

    2017年10月 ~ 2021年10月

  • 日本核医学会 PET短寿命核種の規制にかかる小委員会 委員

    2015年12月 ~ 2018年3月

  • 日本核医学会 WG核医学用ディジタルファントムの作成 メンバー

    2005年4月 ~ 2007年3月

︎全件表示 ︎最初の5件までを表示

所属学協会 4

  • 日本核医学会(1997/10-)

  • 日本脳神経核医学研究会(2012/10-)

  • ISCBFM(2009/03-)

  • IEEE(2005/10-)

研究分野 1

  • ライフサイエンス / 医用システム /

受賞 6

  1. IEEE Senior Member 昇格

    2021年12月

  2. Frequently Cited Paper 2018

    2019年7月 Annals of Nuclear Medicine

  3. 第2回 久田賞

    2010年11月11日 日本核医学会 Annals of Nuclear Medicine機関紙論文賞

  4. 第6回日本核医学会研究奨励賞

    2009年10月 日本核医学会

  5. Finalist for the Niels Lassen Award 2009

    2009年7月 International Society for Cerebral Blood Flow

  6. Young Investigator bursary Award

    2008年6月 Neuroreceptor Mapping 2008

︎全件表示 ︎最初の5件までを表示

論文 75

  1. Preclinical Characterization of the Tau PET Tracer [<sup>18</sup>F]SNFT-1: Comparison of Tau PET Tracers 査読有り

    Ryuichi Harada, Pradith Lerdsirisuk, Yuki Shimizu, Yuka Yokoyama, Yiqing Du, Kaede Kudo, Michinori Ezura, Yoichi Ishikawa, Ren Iwata, Miho Shidahara, Aiko Ishiki, Akio Kikuchi, Yuya Hatano, Tomohiko Ishihara, Osamu Onodera, Yasushi Iwasaki, Mari Yoshida, Yasuyuki Taki, Hiroyuki Arai, Yukitsuka Kudo, Kazuhiko Yanai, Shozo Furumoto, Nobuyuki Okamura

    Journal of Nuclear Medicine jnumed.123.265593-jnumed.123.265593 2023年6月15日

    出版者・発行元:Society of Nuclear Medicine

    DOI: 10.2967/jnumed.123.265593  

    ISSN:0161-5505

    eISSN:2159-662X

  2. Brain partial volume correction with point spreading function reconstruction in high-resolution digital PET: comparison with an MR-based method in FDG imaging 査読有り

    Masanobu Ibaraki, Keisuke Matsubara, Yuki Shinohara, Miho Shidahara, Kaoru Sato, Hiroyuki Yamamoto, Toshifumi Kinoshita

    Ann Nucl Med 36 (8) 717-727 2022年8月

    DOI: 10.1007/s12149-022-01753-5  

    詳細を見る 詳細を閉じる

    OBJECTIVE: In quantitative positron emission tomography (PET) of the brain, partial volume effect due mainly to the finite spatial resolution of the PET scanner (> 3 mm full width at half maximum [FWHM]) is a primary source of error in the measurement of tracer uptake, especially in small structures such as the cerebral cortex (typically < 3 mm thickness). The aim of this study was to evaluate the partial volume correction (PVC) performance of point spread function-incorporated reconstruction (PSF reconstruction) in combination with the latest digital PET scanner. This evaluation was performed through direct comparisons with magnetic resonance imaging (MR)-based PVC (used as a reference method) in a human brain study. METHODS: Ten healthy subjects underwent brain 18F-FDG PET (30-min acquisition) on a digital PET/CT system (Siemens Biograph Vision, 3.5-mm FWHM scanner resolution at the center of the field of view) and anatomical T1-weighted MR imaging for MR-based PVC. PSF reconstruction was applied with a wide range of iterations (4 to 256; 5 subsets). FDG uptake in the cerebral cortex was evaluated using the standardized uptake value ratio (SUVR) and compared between PSF reconstruction and MR-based PVC. RESULTS: Cortical structures were visualized by PSF reconstruction with several tens of iterations and were anatomically well matched with the MR-derived cortical segments. Higher numbers of iterations resulted in higher cortical SUVRs, which approached those of MR-based PVC (1.76), although even with the maximum number of iterations they were still smaller by 16% (1.47), corresponding to approximately 1.5-mm FWHM of the effective spatial resolution. CONCLUSION: With the latest digital PET scanner, PSF reconstruction can be used as a PVC technique in brain PET, albeit with suboptimal resolution recovery. A relative advantage of PSF reconstruction is that it can be applied not only to cerebral cortical regions, but also to various small structures such as small brain nuclei that are hardly visualized on anatomical T1-weighted imaging, and thus hardly recovered by MR-based PVC.

  3. Noninvasive estimation of human radiation dosimetry of 18F-FDG by whole-body small animal PET imaging in rats. 国際誌 査読有り

    Miho Shidahara, Yoshihito Funaki, Hiroshi Watabe

    Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine 181 110071-110071 2022年3月

    DOI: 10.1016/j.apradiso.2021.110071  

    詳細を見る 詳細を閉じる

    PURPOSE: Small animal PET provides the biodistribution of administrated radiotracer in vivo and have a potential to contribute on dosimetry study. The aim of this study is to investigate the effect of region-of-interest (ROI)-delineation in whole-body rat PET image toward non-invasive estimation of human dosimetry of 18F-FDG. METHOD: After administration of 18F-FDG (averaged 11.7 MBq), 3.5-h PET and 20-min CT scans were sequentially performed for three rats by Clairvivo PET/CT system. Seven source organs, and the remainder of the body, were studied to extrapolate %ID(t) and estimate time-integrated activity coefficients [kBq-h/MBq] in human. The mean absorbed dose in each target organ and the effective dose were estimated by MIRD method. Effects of ROI-definitions on both extrapolated %ID(t) in human and estimated doses were also investigated by using (i) small ROIs of high uptake region and (ii) whole organ ROIs. RESULTS: Averaged effective doses of 18F-FDG in human by using high-uptake and whole-organ ROIs were 27.8 ± 6.54 and 19.3 ± 2.72 μSv/MBq, respectively. CONCLUSION: The use of small animal PET scanner, which allows repeatedly PET scans, have a potential to contribute on the reduction of the number of experimental animals. However, the ways of ROI drawing influences on the estimated effective dose and safe-side ROI definition may be preferred.

  4. Iterative framework for image registration and partial volume correction in brain positron emission tomography.

    Keisuke Matsubara, Masanobu Ibaraki, Miho Shidahara, Toshibumi Kinoshita

    Radiological physics and technology 13 (4) 348-357 2020年12月

    DOI: 10.1007/s12194-020-00591-2  

    詳細を見る 詳細を閉じる

    Imprecise registration between positron emission tomography (PET) and anatomical magnetic resonance (MR) images is a critical source of error in MR imaging-guided partial volume correction (MR-PVC). Here, we propose a novel framework for image registration and partial volume correction, which we term PVC-optimized registration (PoR), to address imprecise registration. The PoR framework iterates PVC and registration between uncorrected PET and smoothed PV-corrected images to obtain precise registration. We applied PoR to the [11C]PiB PET data of 92 participants obtained from the Alzheimer's Disease Neuroimaging Initiative database and compared the registration results, PV-corrected standardized uptake value (SUV) and its ratio to the cerebellum (SUVR), and intra-region coefficient of variation (CoV) between PoR and conventional registration. Significant differences in registration of as much as 2.74 mm and 3.02° were observed between the two methods (effect size <  - 0.8 or > 0.8), which resulted in considerable SUVR differences throughout the brain, reaching a maximal difference of 62.3% in the sensory motor cortex. Intra-region CoV was significantly reduced using the PoR throughout the brain. These results suggest that PoR reduces error as a result of imprecise registration in PVC and is a useful method for accurately quantifying the amyloid burden in PET.

  5. Error propagation analysis of seven partial volume correction algorithms for [18F]THK-5351 brain PET imaging. 国際誌 査読有り

    Senri Oyama, Ayumu Hosoi, Masanobu Ibaraki, Colm J McGinnity, Keisuke Matsubara, Shoichi Watanuki, Hiroshi Watabe, Manabu Tashiro, Miho Shidahara

    EJNMMI physics 7 (1) 57-57 2020年9月14日

    DOI: 10.1186/s40658-020-00324-9  

    詳細を見る 詳細を閉じる

    BACKGROUND: Novel partial volume correction (PVC) algorithms have been validated by assuming ideal conditions of image processing; however, in real clinical PET studies, the input datasets include error sources which cause error propagation to the corrected outcome. METHODS: We aimed to evaluate error propagations of seven PVCs algorithms for brain PET imaging with [18F]THK-5351 and to discuss the reliability of those algorithms for clinical applications. In order to mimic brain PET imaging of [18F]THK-5351, pseudo-observed SUVR images for one healthy adult and one adult with Alzheimer's disease were simulated from individual PET and MR images. The partial volume effect of pseudo-observed PET images were corrected by using Müller-Gärtner (MG), the geometric transfer matrix (GTM), Labbé (LABBE), regional voxel-based (RBV), iterative Yang (IY), structural functional synergy for resolution recovery (SFS-RR), and modified SFS-RR algorithms with incorporation of error sources in the datasets for PVC processing. Assumed error sources were mismatched FWHM, inaccurate image-registration, and incorrectly segmented anatomical volume. The degree of error propagations in ROI values was evaluated by percent differences (%diff) of PV-corrected SUVR against true SUVR. RESULTS: Uncorrected SUVRs were underestimated against true SUVRs (- 15.7 and - 53.7% in hippocampus for HC and AD conditions), and application of each PVC algorithm reduced the %diff. Larger FWHM mismatch led to larger %diff of PVC-SUVRs against true SUVRs for all algorithms. Inaccurate image registration showed systematic propagation for most algorithms except for SFS-RR and modified SFS-RR. Incorrect segmentation of the anatomical volume only resulted in error propagations in limited local regions. CONCLUSIONS: We demonstrated error propagation by numerical simulation of THK-PET imaging. Error propagations of 7 PVC algorithms for brain PET imaging with [18F]THK-5351 were significant. Robust algorithms for clinical applications must be carefully selected according to the study design of clinical PET data.

  6. 18F-SMBT-1: A Selective and Reversible Positron-Emission Tomography Tracer for Monoamine Oxidase-B Imaging. 国際誌 査読有り

    Ryuichi Harada, Yoshimi Hayakawa, Michinori Ezura, Pradith Lerdsirisuk, Yiqing Du, Yoichi Ishikawa, Ren Iwata, Miho Shidahara, Aiko Ishiki, Akio Kikuchi, Hiroyuki Arai, Yukitsuka Kudo, Kazuhiko Yanai, Shozo Furumoto, Nobuyuki Okamura

    Journal of nuclear medicine : official publication, Society of Nuclear Medicine 62 (2) 253-258 2020年7月9日

    DOI: 10.2967/jnumed.120.244400  

    詳細を見る 詳細を閉じる

    Reactive astrocytes play a key role in the pathogenesis of various neurodegenerative diseases. Monoamine oxidase-B (MAO-B) is one of the promising targets for the imaging of astrogliosis in the human brain. A novel selective and reversible MAO-B tracer, (S)-(2-methylpyrid-5-yl)-6-[(3-[18F]fluoro-2-hydroxy)propoxy]quinoline, (18F-SMBT-1), was successfully developed via lead optimization from first-generation tau positron-emission tomography (PET) tracer 18F-THK-5351. Methods: SMBT-1 was radiolabeled with fluorine-18 using the corresponding precursor. The binding affinity of radiolabeled compounds to MAO-B was assessed using saturation and competitive binding assays. The binding selectivity of 18F-SMBT-1 to MAO-B was evaluated by autoradiography of frozen human brain tissues. The pharmacokinetics (PK) and metabolism were assessed in normal mice after intravenous administration of 18F-SMBT-1. A 14-day toxicity study following the intravenous administration of SMBT-1 was performed using rats and mice. Results: In vitro binding assays demonstrated a high binding affinity of SMBT-1 to MAO-B (KD = 3.7 nM). In contrast, it showed low binding affinity to MAO-A and protein aggregates such as amyloid-β and tau fibrils. Autoradiographic analysis showed higher amounts of 18F-SMBT-1 binding in the Alzheimer's disease (AD) brain sections than in the control brain sections. 18F-SMBT-1 binding was completely displaced with reversible MAO-B inhibitor lazabemide, demonstrating the high selectivity of 18F-SMBT-1 for MAO-B. Furthermore, 18F-SMBT-1 showed a high uptake by brain, rapid washout, and no radiolabeled metabolites in the brain of normal mice. SMBT-1 showed no significant binding to various receptors, ion channels, and transporters, and no toxic effects related to its administration were observed in mice and rats. Conclusion:18F-SMBT-1 is a promising and selective MAO-B PET tracer candidate, which would be useful for quantitative monitoring of astrogliosis in the human brain.

  7. From the respective expert viewpoints of the ANM specialty editors

    Masayuki Inubushi, Miho Shidahara, Yasuyuki Takahashi, Mikako Ogawa, Yasushi Kiyono

    Annals of Nuclear Medicine 33 (12) 877-880 2019年12月

    出版者・発行元:Springer Science and Business Media LLC

    DOI: 10.1007/s12149-019-01421-1  

    ISSN:0914-7187

    eISSN:1864-6433

    詳細を見る 詳細を閉じる

    <title>Abstract</title>Although it may not be well known, the Annals of Nuclear Medicine (ANM) Editorial Committee includes one specialty editor of nuclear medicine physics, one of nuclear medicine technology, one of molecular imaging, and two of radiopharmacology. In addition, a statistics editor and a language editor are also on the committee. Manuscripts submitted to ANM can be peer-reviewed by such specialty editors similar to those submitted to highly ranked journals, which is a great pride and joy to us. To offer our readers a condensed global view on the high-quality research work in the field of nuclear medicine, we have published a mini-review article every year under the joint authorship of the ANM associate editors since 2016. This is our fourth serial review article written by the ANM specialty editors from their respective expert viewpoints.

  8. Altered Gender Difference in Brain Histamine H1 Receptor Binding in Patients with Irritable Bowel Syndrome: A Positron Emission Tomography Study 査読有り

    Morishita J, Shidahara M, Shoji T, Endo Y, Sato Y, Kano M, Kanazawa M, Tashiro M, Yanai K, Fukudo S

    Gastroenterology 156 (6) S-26-S-27 2019年5月

  9. Biomathematical Modeling Approach to Predict Clinical SUVRs for Amyloid PET Imaging

    Shidahara M, Seki C, Nai YH, Okamura, Furumoto S, Yanai K, Watabe H, Tashiro M

    CYRIC Annual Report 2016-2017 147-151 2019年4月

  10. Partial Volume Corrections for Tau and Amyloid PET Imaging with [18F]THK5351 and [11C]PiB

    Shidahara M, Thomas AB, Okamura N, Ibaraki M, Matsubara K, Oyama S, Ishikawa Y, Watanuki S, Iwata R, Furumoto S, Yanai K, Watabe H, Tashiro M

    CYRIC Annual Report 2016-2017 142-146 2019年4月

  11. A systematic performance evaluation of head motion correction techniques for 3 commercial PET scanners using a reproducible experimental acquisition protocol. 査読有り

    Inomata T, Watanuki S, Odagiri H, Nambu T, Karakatsanis NA, Ito H, Watabe H, Tashiro M, Shidahara M

    Annals of nuclear medicine 33 (7) 459-470 2019年3月

    出版者・発行元:None

    DOI: 10.1007/s12149-019-01353-w  

    ISSN:0914-7187

    eISSN:1864-6433

  12. Renal statistical map for positron emission tomography with [O-15] water. 国際誌 査読有り

    Mahabubur Rahman, Hiroshi Watabe, Miho Shidahara, Shoichi Watanuki, Manabu Tashiro, Takefumi Mori, Sadayoshi Ito, Yusuke Ohsaki

    American journal of nuclear medicine and molecular imaging 9 (4) 193-202 2019年

    ISSN:2160-8407

    詳細を見る 詳細を閉じる

    Image statistics are frequently used for functional and molecular imaging research in which images from a patient group with a specific diagnosis are compared with images from a healthy control group who have been matched for demographic variables. The success of image statistics for brain imaging has encouraged us to develop a method for obtaining volumetrically normalized kidney to perform image statistics so that we can locally visualize the statistical significant difference comparing voxel by voxel between certain groups in terms kidney blood flow kinetic parameters. For the development of this evolutionary process, we first volumetrically normalized all subjects, which include healthy control (HC) and chronic renal failure (CRF) patients, 15O water PET image with respect to one HC subject's MRI image using affine transformation. Then 15O kinetic parametric images of normalized kidneys were obtained through the basis function method. Finally, the statistical map of these parametric images was produced using the threshold-free cluster enhancement based permutation method. Kinetic parameters of kidney namely, uptake rate constant (K1), clearance rate constant (k2) and blood volume (Va), were found to be notably lower in CRF than those of in HC and k2 parameter was found to be more stable compared to K1 and Va. The statistical map of these parametric images allowed us to visualize local significant differences statistically (P<0.05) between HC and CRF groups. Though PET and MRI techniques have enormous potentiality for functional and molecular imaging of kidney, these are, at best, in experimental level. It is speculated that statistical mapping of kidney could play a significant role in the successful implementation of functional and molecular kidney imaging. However, more research involving a larger sample size and improved normalization technique will be needed for the robustness of the process.

  13. 頭部PET体動補正精度の装置間比較 統一実験プロトコルを用いた検討

    猪又 嵩斗, 志田原 美保, 四月朔日 聖一, 小田桐 逸人, 南部 武幸, 伊藤 浩, 田代 学, 渡部 浩司

    核医学技術 38 (予稿集) 403-403 2018年10月

    出版者・発行元:(NPO)日本核医学技術学会

    ISSN:0289-100X

  14. Error propagation properties of 5 partial volume correction algorithms for [F-18]THK5351 PET imaging 査読有り

    Oyama S, Shidahara M, Thomas B. A, Matsubara K, Ibaraki M, Watanuki S, Watabe H, Tashiro M

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 45 S300 2018年10月

    ISSN:1619-7070

  15. Biomathematical screening of amyloid radiotracers with clinical usefulness index 査読有り

    Ying-Hwey Nai, Miho Shidahara, Chie Seki, Hiroshi Watabe

    Alzheimer's and Dementia: Translational Research and Clinical Interventions 3 (4) 542-552 2017年11月1日

    出版者・発行元:Elsevier Inc

    DOI: 10.1016/j.trci.2017.08.006  

    ISSN:2352-8737

    詳細を見る 詳細を閉じる

    Introduction To facilitate radiotracers' development, a screening methodology using a biomathematical model and clinical usefulness index (CUI) was proposed to evaluate radiotracers' diagnostic capabilities. Methods A total of 31 amyloid positron emission tomography radiotracers were evaluated. A previously developed biomathematical model was used to simulate 1000 standardized uptake value ratios with population and noise simulations, which were used to determine the integrated receiver operating characteristics curve (Az), effect size (Es), and standardized uptake value ratio (Sr) of conditions-pairs of healthy control–mild cognitive impaired and mild cognitive impaired–Alzheimer's disease. CUI was obtained from the product of averaged Az(Az¯), Es(Es¯), and Sr(Sr¯). Results The relationships of Az¯, Es¯, and Sr¯ with CUI were different, suggesting that they assessed different radiotracer properties. The combination of Az, Es, and Sr complemented each other and resulted in CUI of 0.10 to 5.72, with clinically applied amyloid positron emission tomography radiotracers having CUI greater than 3.0. Discussion The CUI rankings of clinically applied radiotracers were close to their reported clinical results, attesting to the applicability of the screening methodology.

  16. ラットPETを用いたヒト内部被曝線量の非侵襲的推定手法の検討

    志田原 美保, 猪又 嵩斗, 小山 千莉, 船木 善仁, 田代 学, 古本 祥三, 谷内 一彦, 権田 幸祐, 渡部 浩司

    核医学 54 (Suppl.) S199-S199 2017年9月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  17. トレーサブル68Ge/68Ga点状線源を用いるPET装置の校正法

    小山 翔司, 長谷川 智之, 井上 優介, 菊池 敬, 宮武 比呂樹, 我妻 慧, 宮司 典明, 渡部 浩司, 志田原 美保, 四月朔日 聖一, 津田 啓介, 村松 禎久, 柳澤 かおり, 和田 康弘, 織田 圭一, 佐藤 泰

    核医学技術 37 (予稿集) 481-481 2017年9月

    出版者・発行元:(NPO)日本核医学技術学会

    ISSN:0289-100X

  18. 137Cs transmission imaging and segmented attenuation corrections in a small animal PET scanner 査読有り

    Ying-Hwey Nai, Takayuki Ose, Miho Shidahara, Hiroshi Watabe

    Radiological Physics and Technology 10 (3) 321-330 2017年9月1日

    出版者・発行元:Springer Tokyo

    DOI: 10.1007/s12194-017-0407-4  

    ISSN:1865-0341 1865-0333

    詳細を見る 詳細を閉じる

    Attenuation correction (AC) is required for accurate quantitative evaluation of small animal PET data. Our objective was to compare three AC methods in the small animal Clairvivo-PET scanner. The three AC methods involve applying attenuation coefficient maps generated by simulating a cylindrical map (SAC), segmenting the emission data (ESAC), and segmenting the transmission data (TSAC), imaged using a 137Cs single-photon source. Investigation was carried out using a 65 mm uniform cylinder and an NEMA NU4 2008 mouse phantom, filled with water or tungsten liquid, to mimic bone. Evaluation was carried out using the difference of the segmented map volume from the known cylindrical phantom volume, the recovery of the radioactivity concentration, and the line profiles. The optimal transmission scan time for achieving accurate AC using TSAC was determined using 5, 10, 15, 20, and 25 min transmission scan time. The effects of scatter correction and reconstruction algorithms on ESAC were investigated. SAC showed the best performance but was unable to correct for different tissues and the scanner bed, and faced difficulty with correct positioning of the attenuation coefficient map. ESAC was affected by scatter correction and reconstruction algorithm, and may result in poor boundary delineation, and hence was unreliable. TSAC showed reasonable performance but required further optimization of the default segmentation setting. A minimum transmission scan time of 20 min is recommended for Clairvivo-PET using 137Cs source to ensure that sufficient transmission counts are obtained to generate accurate attenuation coefficient map.

  19. Prediction of the Clinical SUV Ratio in Amyloid PET Imaging Using a Biomathematic Modeling Approach Toward the Efficient Development of a Radioligand 査読有り

    Yuma Arakawa, YingHwey Nai, Miho Shidahara, Shozo Furumoto, Chie Seki, Nobuyuki Okamura, Manabu Tashiro, Yukitsuka Kudo, Kazuhiko Yanai, Kohsuke Gonda, Hiroshi Watabe

    JOURNAL OF NUCLEAR MEDICINE 58 (8) 1285-1292 2017年8月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    DOI: 10.2967/jnumed.116.183566  

    ISSN:0161-5505

    eISSN:1535-5667

    詳細を見る 詳細を閉じる

    Our study aimed to develop a method to mathematically predict the kinetic parameters K-1 (influx rate constant), k(2) (efflux rate constant), and BPND (nondisplaceable binding potential) of amyloid PET tracers and obtain SUV ratios (SUVRs) from predicted timeactivity curves of target and reference regions. Methods: We investigated 10 clinically applied amyloid PET radioligands: C-11-Pittsburgh compound B, C-11-BF-227, C-11-AZD2184, C-11-SB-13, F-18-FACT, F-18-florbetapir, F-18-florbetaben, F-18-flutemetamol, F-18-FDDNP, and F-18-AZD4694. For each tracer, time-activity curves of both target and reference regions were generated using a simplified 1-tissue-compartment model, with an arterial plasma input function and the predicted kinetic parameters. K-1, k(2), and BPND were derived from the lipophilicity (logP), apparent volume, free fraction in plasma, free fraction in tissue, dissociation constant, and density of amyloid beta using biomathematic modeling. Density was fixed at 3 nM to represent healthy control conditions and 50 nM to represent severe Alzheimer disease (AD). Predicted SUVRs for the healthy and AD groups were then obtained by dividing the integrated time-activity curve of the target region by that of the reference region. To validate the presented method, the predicted K-1, k(2), BPND, and SUVR for the healthy and AD groups were compared with the respective clinically observed values. Results: The correlation between predicted and clinical kinetic parameters had an R-2 value of 0.73 for K-1 in the healthy group, 0.71 for K-1 in the AD group, 0.81 for k(2) in the healthy group, 0.85 for k(2) in the AD group, and 0.63 for BPND in the AD group. The regression relationship between the predicted SUVR (y) and the clinical SUVR (x) for the healthy and the AD groups was y 5 2.73x - 2.11 (R-2 = 0.72). Conclusion: The proposed method showed a good correlation between predicted and clinical SUVR for the 10 clinically applied amyloid tracers.

  20. A comparison of five partial volume correction methods for Tau and Amyloid PET imaging with [F-18]THK5351 and [C-11]PIB 査読有り

    Miho Shidahara, Benjamin A. Thomas, Nobuyuki Okamura, Masanobu Ibaraki, Keisuke Matsubara, Senri Oyama, Yoichi Ishikawa, Shoichi Watanuki, Ren Iwata, Shozo Furumoto, Manabu Tashiro, Kazuhiko Yanai, Kohsuke Gonda, Hiroshi Watabe

    ANNALS OF NUCLEAR MEDICINE 31 (7) 563-569 2017年8月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s12149-017-1185-0  

    ISSN:0914-7187

    eISSN:1864-6433

    詳細を見る 詳細を閉じる

    Purpose To suppress partial volume effect (PVE) in brain PET, there have been many algorithms proposed. However, each methodology has different property due to its assumption and algorithms. Our aim of this study was to investigate the difference among partial volume correction (PVC) method for tau and amyloid PET study. Methods We investigated two of the most commonly used PVC methods, Muller-Gartner (MG) and geometric transfer matrix (GTM) and also other three methods for clinical tau and amyloid PET imaging. One healthy control (HC) and one Alzheimer's disease (AD) PET studies of both [F-18]THK5351 and [C-11]PIB were performed using a Eminence STARGATE scanner (Shimadzu Inc., Kyoto, Japan). All PET images were corrected for PVE by MG, GTM, Labb, (LABBE), Regional voxel-based (RBV), and Iterative Yang (IY) methods, with segmented or parcellated anatomical information processed by FreeSurfer, derived from individual MR images. PVC results of 5 algorithms were compared with the uncorrected data. Results In regions of high uptake of [F-18]THK5351 and [C-11]PIB, different PVCs demonstrated different SUVRs. The degree of difference between PVE uncorrected and corrected depends on not only PVC algorithm but also type of tracer and subject condition. Conclusions Presented PVC methods are straight-forward to implement but the corrected images require careful interpretation as different methods result in different levels of recovery.

  21. Validation of a Novel Calibration Method Using a Traceable 68Ge/68Ga Point-Like Source On Eleven Types of PET Scanners 査読有り

    Koyama S, Hasegawa T, Miyatake H, Inoue Y, Kikuchi K, Wagatsuma K, Miyaji N, Watabe H, Shidahara M, Watanuki S, Tsuda K, Muramatsu Y, Yanagisawa K, Wada Y, Oda K, Sato Y, Yamada T

    MEDICAL PHYSICS 44 (6) 2017年6月

    ISSN:0094-2405

  22. F-18-THK5351: A Novel PET Radiotracer for Imaging Neurofibrillary Pathology in Alzheimer Disease 査読有り

    Ryuichi Harada, Nobuyuki Okamura, Shozo Furumoto, Katsutoshi Furukawa, Aiko Ishiki, Naoki Tomita, Tetsuro Tago, Kotaro Hiraoka, Shoichi Watanuki, Miho Shidahara, Masayasu Miyake, Yoichi Ishikawa, Rin Matsuda, Akie Inami, Takeo Yoshikawa, Yoshihito Funaki, Ren Iwata, Manabu Tashiro, Kazuhiko Yanai, Hiroyuki Arai, Yukitsuka Kudo

    JOURNAL OF NUCLEAR MEDICINE 57 (2) 208-214 2016年2月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    DOI: 10.2967/jnumed.115.164848  

    ISSN:0161-5505

    eISSN:1535-5667

    詳細を見る 詳細を閉じる

    Imaging of neurofibrillary pathology in the brain helps in diagnosing dementia, tracking disease progression, and evaluating the therapeutic efficacy of antidementia drugs. The radiotracers used in this imaging must be highly sensitive and specific for tau protein fibrils in the human brain. We developed a novel-tau PET tracer, F-18-THK5351, through compound optimization of arylquinoline derivatives. Methods: The in vitro binding properties, pharmacokinetics, and safety of F-18-THK5351 were investigated, and a clinical study on Alzheimer disease (AD) patients was performed. Results: F-18-THK5351 demonstrated higher binding affinity for hippocampal homogenates from AD brains and faster dissociation from white matter tissue than did F-18-THK5117. The THK5351 binding amount correlated with the amount of tau deposits in human brain samples. Autoradiography of brain sections revealed that THK5351 bound to neurofibrillary tangles selectively and with a higher signal-to background ratio than did THK5117. THK5351 exhibited favorable pharmacokinetics and no defluorination in mice. In first-in-human PET studies in AD patients, F-18-THK5351 demonstrated faster kinetics, higher contrast, and lower retention in subcortical white matter than F-18-THK5117. Conclusion: F-18-THK5351 is a useful PET tracer for the early detection of neurofibrillary pathology in AD patients.

  23. Performance evaluation of the small-animal PET scanner ClairvivoPET using NEMA NU 4-2008 Standards 査読有り

    K. Sato, M. Shidahara, H. Watabe, S. Watanuki, Y. Ishikawa, Y. Arakawa, Y. H. Nai, S. Furumoto, M. Tashiro, T. Shoji, K. Yanai, K. Gonda

    PHYSICS IN MEDICINE AND BIOLOGY 61 (2) 696-711 2016年1月

    出版者・発行元:IOP PUBLISHING LTD

    DOI: 10.1088/0031-9155/61/2/696  

    ISSN:0031-9155

    eISSN:1361-6560

    詳細を見る 詳細を閉じる

    The aim of this study was to evaluate the performance of ClairvivoPET using NEMA NU4 standards. The ClairvivoPET incorporates a LYSO dual depth-of-interaction detector system with 151 mm axial field of view (FOV). Spatial resolution, sensitivity, counting rate capabilities, and image quality were evaluated using NEMA NU4-2008 standards. Normal mouse imaging was also performed for 10min after intravenous injection of F-18(-)-NaF. Data were compared with 19 other preclinical PET scanners. Spatial resolution measured using full width at half maximum on FBP-ramp reconstructed images was 2.16 mm at radial offset 5 mm of the axial centre FOV. The maximum absolute sensitivity for a point source at the FOV centre was 8.72%. Peak noise equivalent counting rate (NECR) was 415kcps at 14.6MBq ml(-1). The uniformity with the image-quality phantom was 4.62%. Spillover ratios in the images of air and water filled chambers were 0.19 and 0.06, respectively. Our results were comparable with the 19 other preclinical PET scanners based on NEMA NU4 standards, with excellent sensitivity because of the large FOV. The ClairvivoPET with iterative reconstruction algorithm also provided sufficient visualization of the mouse spine. The high sensitivity and resolution of the ClairvivoPET scanner provided high quality images for preclinical studies.

  24. PET解析技術の開発

    渡部浩司, 志田原美保

    放射線 41 (4) 191-195 2016年

    出版者・発行元:応用物理学会放射線分科会

    ISSN:0285-3604

  25. Quantitative kinetic analysis of PET amyloid imaging agents [C-11]BF227 and [F-18]FACT in human brain 査読有り

    Miho Shidahara, Hiroshi Watabe, Manabu Tashiro, Nobuyuki Okamura, Shozo Furumoto, Shoichi Watanuki, Katsutoshi Furukawa, Yuma Arakawa, Yoshihito Funaki, Ren Iwata, Kohsuke Gonda, Yukitsuka Kudo, Hiroyuki Arai, Kiichi Ishiwata, Kazuhiko Yanai

    NUCLEAR MEDICINE AND BIOLOGY 42 (9) 734-744 2015年9月

    出版者・発行元:ELSEVIER SCIENCE INC

    DOI: 10.1016/j.nucmedbio.2015.05.001  

    ISSN:0969-8051

    eISSN:1872-9614

    詳細を見る 詳細を閉じる

    Introduction: The purpose of this study was to compare two amyloid imaging agents, [C-11]BF227 and [F-18]FACT (derivative from [C-11]BF227) through quantitative pharmacokinetics analysis in human brain. Methods: Positron emission tomography studies were performed on six elderly healthy control (HC) subjects and seven probable Alzheimer's disease (AD) patients with [C-11]BF227 and 10 HC subjects and 10 probable AD patients with [F-18]FACT. Data from nine regions of interest were analyzed by several approaches, namely non-linear least-squared fitting methods with arterial input functions (one-tissue compartment model(1TCM), two-tissue compartment model (2TCM)), Logan plot, and linearized methods with reference region (Reference Logan plot (RefLogan), MRTM0, MRTM2). We also evaluated SUV and SUVR for both tracers. The parameters estimated by several approaches were compared between two tracers for detectability of differences between HC and AD patients. Results: For [C-11]BF227, there were no significant difference of V-T (2TCM, 1TCM) and SUV in all regions (Student t-test; p &lt; 0.05) and significant differences in the DVRs (Logan, RefLogan, and MRTM2) and SUVRs in six neocortical regions (p &lt; 0.05) between the HC and AD groups. For [F-18]FACT, significant differences in DVRs (RefLogan, MRTM0, and MRTM2) were observed in more than four neocortical regions between the HC and AD groups (p &lt; 0.05), and the significant differences were found in SUVRs for two neocortical regions (inferior frontal coretex and lateral temporal coretex). Our results showed that both tracers can clearly distinguish between HC and AD groups although the pharmacokinetics and distribution patterns in brain for two tracers were substantially different. Conclusion: This study revealed that although the PET amyloid imaging agents [C-11]BF227 and [F-18]FACT have similar chemical and biological properties, they have different pharmacokinetics, and caution must be paid for usage of the tracers. (C) 2015 Elsevier Inc. All rights reserved.

  26. Aliased noise in X-ray CT images and band-limiting processing as a preventive measure 査読有り

    Kazuhiro Sato, Miho Shidahara, Mitsunori Goto, Isao Yanagawa, Noriyasu Homma, Issei Mori

    Radiological Physics and Technology 8 (2) 178-192 2015年7月23日

    出版者・発行元:Springer-Verlag Tokyo

    DOI: 10.1007/s12194-015-0306-5  

    ISSN:1865-0341 1865-0333

    詳細を見る 詳細を閉じる

    X-ray CT projection data often include components with frequencies that are markedly higher than the pixel Nyquist frequency fPN, which is determined by the pixel size. Noise components higher than fPN are folded back into a region lower than fPN through the backprojection process, thereby creating aliased noise. With clinical CT scanners, we evaluated the aliased noise using an aliasing prevention measure, band-limiting processing (BLP), which suppresses frequency components higher than fPN in the projection data. Indices we used to evaluate improvement by BLP were the noise power spectrum (NPS), modulation transfer function (MTF), signal-to-noise-ratio (SNR) spectrum, matched filter SNR (MF SNR), and two-alternative forced-choice (2-AFC) test. With BLP, the NPS was decreased not only beyond fPN, but also within fPN. The same level of MTF was maintained as that without BLP within fPN. No remarkable reduction in spatial resolution was observed. The SNR spectrum and the MF SNR of the BLP image nearly agreed with those of an ideal state without aliased noise. A notable improvement in the visuoperceptual image quality by BLP was recognized with a reconstruction field of view (FOV) of more than 45 cm. We then applied BLP to clinical data and confirmed that significant aliased noise of a large FOV image was removed without notable side effects. The results showed that at least some CTs suffering from aliased noise can be improved by proper band-limiting.

  27. [F-18]THK-5117 PET for assessing neurofibrillary pathology in Alzheimer's disease 査読有り

    Ryuichi Harada, Nobuyuki Okamura, Shozo Furumoto, Katsutoshi Furukawa, Aiko Ishiki, Naoki Tomita, Kotaro Hiraoka, Shoichi Watanuki, Miho Shidahara, Masayasu Miyake, Yoichi Ishikawa, Rin Matsuda, Akie Inami, Takeo Yoshikawa, Tetsuro Tago, Yoshihito Funaki, Ren Iwata, Manabu Tashiro, Kazuhiko Yanai, Hiroyuki Arai, Yukitsuka Kudo

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 42 (7) 1052-1061 2015年6月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s00259-015-3035-4  

    ISSN:1619-7070

    eISSN:1619-7089

    詳細を見る 詳細を閉じる

    Purpose Visualization of the spatial distribution of neurofibrillary tangles would help in the diagnosis, prevention and treatment of dementia. The purpose of the study was to evaluate the clinical utility of [F-18]THK-5117 as a highly selective tau imaging radiotracer. Methods We initially evaluated in vitro binding of [H-3]THK-5117 in post-mortem brain tissues from patients with Alzheimer's disease (AD). In clinical PET studies, [F-18]THK-5117 retention in eight patients with AD was compared with that in six healthy elderly controls. Ten subjects underwent an additional [C-11]PiB PET scan within 2 weeks. Results In post-mortem brain samples, THK-5117 bound selectively to neurofibrillary deposits, which differed from the binding target of PiB. In clinical PET studies, [F-18]THK-5117 binding in the temporal lobe clearly distinguished patients with AD from healthy elderly subjects. Compared with [C-11]PiB, [F-18]THK-5117 retention was higher in the medial temporal cortex. Conclusion These findings suggest that [F-18]THK-5117 provides regional information on neurofibrillary pathology in living subjects.

  28. Kinetic Models for PET/SPECT Imaging.

    Miho Shidahara, Hiroshi Watabe, Iwao Kanno

    Encyclopedia of Computational Neuroscience 2014年

    出版者・発行元:Springer

    DOI: 10.1007/978-1-4614-7320-6_526-1  

  29. Quantification of opioid receptor availability following spontaneous epileptic seizures: Correction of [11C]diprenorphine PET data for the partial-volume effect 査読有り

    Colm J. McGinnity, Miho Shidahara, Maria Feldmann, Shiva Keihaninejad, Daniela A. Riaño Barros, Ioannis S. Gousias, John S. Duncan, David J. Brooks, Rolf A. Heckemann, Federico E. Turkheimer, Alexander Hammers, Matthias J. Koepp

    NeuroImage 79 72-80 2013年10月1日

    DOI: 10.1016/j.neuroimage.2013.04.015  

    ISSN:1053-8119 1095-9572

    詳細を見る 詳細を閉じる

    Previous positron emission tomography (PET) studies in refractory temporal lobe epilepsy (TLE) using the non-selective opioid receptor antagonist [11C]diprenorphine (DPN) did not detect any changes in mesial temporal structures, despite known involvement of the hippocampus in seizure generation. Normal binding in smaller hippocampi is suggestive of increased receptor concentration in the remaining grey matter. Correction for partial-volume effect (PVE) has not been used in previous DPN PET studies. Here, we present PVE-corrected DPN-PET data quantifying post-ictal and interictal opioid receptor availability in humans with mTLE.Eight paired datasets of post-ictal and interictal DPN PET scans and eleven test/retest control datasets were available from a previously published study on opioid receptor changes in TLE following seizures (Hammers et al., 2007a). Five of the eight participants with TLE had documented hippocampal sclerosis. Data were re-analyzed using regions of interest and a novel PVE correction method (structural functional synergistic-resolution recovery (SFS-RR) (Shidahara et al., 2012)). Data were denoised, followed by application of SFS-RR, with anatomical information derived via precise anatomical segmentation of the participants' MRI (MAPER (Heckemann et al., 2010)). [11C]diprenorphine volume-of-distribution (VT) was quantified in six regions of interest.Post-ictal increases were observed in the ipsilateral fusiform gyri and lateral temporal pole. A novel finding was a post-ictal increase in [11C]DPN VT relative to the interictal state in the ipsilateral parahippocampal gyrus, not observed in uncorrected datasets. As for voxel-based (SPM) analyses, correction for global VT values was essential in order to demonstrate focal post-ictal increases in [11C]DPN VT.This study provides further direct human in vivo evidence for changes in opioid receptor availability in TLE following seizures, including changes that were not evident without PVE correction. Denoising, resolution recovery and precise anatomical segmentation can extract valuable information from PET studies that would be missed with conventional post-processing procedures. © 2013.

  30. Partial volume correction using structural-functional synergistic resolution recovery: comparison with geometric transfer matrix method 査読有り

    Euitae Kim, Miho Shidahara, Charalampos Tsoumpas, Colm J. McGinnity, Jun Soo Kwon, Oliver D. Howes, Federico E. Turkheimer

    JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM 33 (6) 914-920 2013年6月

    出版者・発行元:SAGE PUBLICATIONS INC

    DOI: 10.1038/jcbfm.2013.29  

    ISSN:0271-678X

    eISSN:1559-7016

    詳細を見る 詳細を閉じる

    We validated the use of a novel image-based method for partial volume correction (PVC), structural-functional synergistic resolution recovery (SFS-RR) for the accurate quantification of dopamine synthesis capacity measured using [F-18]DOPA positron emission tomography. The bias and reliability of SFS-RR were compared with the geometric transfer matrix (GTM) method. Both methodologies were applied to the parametric maps of [F-18]DOPA utilization rates (k(i)(cer)). Validation was first performed by measuring repeatability on test-retest scans. The precision of the methodologies instead was quantified using simulated [F-18]DOPA images. The sensitivity to the misspecification of the full-width-half-maximum (FWHM) of the scanner point-spread-function on both approaches was also assessed. In the in-vivo data, the k(i)(cer) was significantly increased by application of both PVC procedures while the reliability remained high (intraclass correlation coefficients &gt;0.85). The variability was not significantly affected by either PVC approach (&lt;10% variability in both cases). The corrected k(i)(cer) was significantly influenced by the FWHM applied in both the acquired and simulated data. This study shows that SFS-RR can effectively correct for partial volume effects to a comparable degree to GTM but with the added advantage that it enables voxelwise analyses, and that the FWHM used can affect the PVC result indicating the importance of accurately calibrating the FWHM used in the recovery model.

  31. Evaluation of the biodistribution and radiation dosimetry of the 18F-labelled amyloid imaging probe [18F]FACT in humans. 国際誌 査読有り

    Miho Shidahara, Manabu Tashiro, Nobuyuki Okamura, Shozo Furumoto, Katsutoshi Furukawa, Shoichi Watanuki, Kotaro Hiraoka, Masayasu Miyake, Ren Iwata, Hajime Tamura, Hiroyuki Arai, Yukitsuka Kudo, Kazuhiko Yanai

    EJNMMI research 3 (1) 32-32 2013年4月24日

    DOI: 10.1186/2191-219X-3-32  

    詳細を見る 詳細を閉じる

    BACKGROUND: The biodistribution and radiation dosimetry of the 18F-labelled amyloid imaging probe ([18F] FACT) was investigated in humans. METHODS: Six healthy subjects (three males and three females) were enrolled in this study. An average of 160.8 MBq of [18F] FACT was intravenously administered, and then a series of whole-body PET scans were performed. Nineteen male and 20 female source organs, and the remainder of the body, were studied to estimate time-integrated activity coefficients. The mean absorbed dose in each target organ and the effective dose were estimated from the time-integrated activity coefficients in the source organs. Biodistribution data from [18F] FACT in mice were also used to estimate absorbed doses and the effective dose in human subjects; this was compared with doses of [18F] FACT estimated from human PET data. RESULTS: The highest mean absorbed doses estimated using human PET data were observed in the gallbladder (333 ± 251 μGy/MBq), liver (77.5 ± 14.5 μGy/MBq), small intestine (33.6 ± 30.7 μGy/MBq), upper large intestine (29.8 ± 15.0 μGy/MBq) and lower large intestine (25.2 ± 12.6 μGy/MBq). The average effective dose estimated from human PET data was 18.6 ± 3.74 μSv/MBq. The highest mean absorbed dose value estimated from the mouse data was observed in the small intestine (38.5 μGy/MBq), liver (25.5 μGy/MBq) and urinary bladder wall (43.1 μGy/MBq). The effective dose estimated from the mouse data was 14.8 μSv/MBq for [18F] FACT. CONCLUSIONS: The estimated effective dose from the human PET data indicated that the [18F] FACT PET study was acceptable for clinical purposes.

  32. 呼吸性移動の影響を補正したSUV評価法に関する検討

    小笠原誠, 伊藤謙吾, 志田原美保, 土橋卓, 武田 賢, 角谷倫之, 藤田幸男, 南部武幸, 岸 和馬, 金田朋洋, 神宮啓一

    日本放射線技術学会東北部会雑誌 22 238-239 2013年1月

  33. Wavelet-based resolution recovery using an anatomical prior provides quantitative recovery for human population phantom PET [C-11]raclopride data 査読有り

    M. Shidahara, C. Tsoumpas, C. J. McGinnity, T. Kato, H. Tamura, A. Hammers, H. Watabe, F. E. Turkheimer

    PHYSICS IN MEDICINE AND BIOLOGY 57 (10) 3107-3122 2012年5月

    出版者・発行元:IOP PUBLISHING LTD

    DOI: 10.1088/0031-9155/57/10/3107  

    ISSN:0031-9155

    eISSN:1361-6560

    詳細を見る 詳細を閉じる

    The objective of this study was to evaluate a resolution recovery (RR) method using a variety of simulated human brain [C-11] raclopride positron emission tomography (PET) images. Simulated datasets of 15 numerical human phantoms were processed by a wavelet-based RR method using an anatomical prior. The anatomical prior was in the form of a hybrid segmented atlas, which combined an atlas for anatomical labelling and a PET image for functional labelling of each anatomical structure. We applied RR to both 60 min static and dynamic PET images. Recovery was quantified in 84 regions, comparing the typical 'true' value for the simulation, as obtained in normal subjects, simulated and RR PET images. The radioactivity concentration in the white matter, striatum and other cortical regions was successfully recovered for the 60 min static image of all 15 human phantoms; the dependence of the solution on accurate anatomical information was demonstrated by the difficulty of the technique to retrieve the subthalamic nuclei due to mismatch between the two atlases used for data simulation and recovery. Structural and functional synergy for resolution recovery (SFS-RR) improved quantification in the caudate and putamen, the main regions of interest, from-30.1% and-26.2% to-17.6% and-15.1%, respectively, for the 60 min static image and from-51.4% and-38.3% to-27.6% and-20.3% for the binding potential (BPND) image, respectively. The proposed methodology proved effective in the RR of small structures from brain [C-11] raclopride PET images. The improvement is consistent across the anatomical variability of a simulated population as long as accurate anatomical segmentations are provided.

  34. Wavelet-based resolution recovery using anatomical prior provides quantitative recovery for human population phantom PET [ 11C] raclopride data 査読有り

    Miho Shidahara, Charalampos Tsoumpas, Colm McGinnity, Takashi Kato, Hajime Tamura, Alexander Hammers, Hiroshi Watabe, Federico E. Turkheimer

    IEEE Nuclear Science Symposium Conference Record 3097-3101 2012年

    DOI: 10.1109/NSSMIC.2011.6152561  

    ISSN:1095-7863

    詳細を見る 詳細を閉じる

    The purpose of this study was the evaluation of a wavelet-based resolution recovery (RR) method, named structural and functional synergy for RR (SFS-RR), for a variety of simulated human brain [ 11C]raclopride PET images. Simulated datasets of 15 human phantoms were processed by SFS-RR using an anatomical prior. This anatomical information was in the form of a hybrid segmented-atlas, which combines an MRI for anatomical labelling and a PET image for functional labelling of each anatomical structure. First, the relationship between the FWHM of the original the PET image and its resolution recovered version was investigated. Then quantitative evaluation was performed by comparing caudate, putamen and cerebellum regions of the true image simulated PET image and RR image. The spatial resolution of the original PET image effected on how accurately SFS-RR recovers the image counts in striatum regions. The resolution in striatum, and cerebellum regions was successfully recovered for all the 15 human phantoms. The proposed methodology proved effective in the resolution recovery of small structures of brain [ 11C]raclopride PET images. The improvement was consistent across the anatomical variability of a simulated population, provided accurate anatomical segmentations are available. © 2011 IEEE.

  35. In vivo Measurement of Longitudinal Relaxation Time of Human Blood by Inversion-recovery Fast Gradient-echo MR Imaging at 3T 査読有り

    Kazuki Shimada, Tatsuo Nagasaka, Miho Shidahara, Yoshio Machida, Hajime Tamura

    MAGNETIC RESONANCE IN MEDICAL SCIENCES 11 (4) 265-271 2012年

    出版者・発行元:JPN SOC MAGNETIC RESONANCE IN MEDICINE

    DOI: 10.2463/mrms.11.265  

    ISSN:1347-3182

    詳細を見る 詳細を閉じる

    Purpose: Accurate longitudinal relaxation time (T-1) of arterial blood is important in evaluating blood flow in tissue by arterial spin labeling magnetic resonance (MR) imaging. Few studies have reported the T-1 of human arterial blood in vivo, especially using 3-tesla MR imaging. T-1 values of human venous blood in vivo have been reported, but they differ from those measured in vitro. We aimed to evaluate the accurate T-1 of human arterial blood in vivo. Methods: We measured T-1 values of blood in 10 healthy volunteers in vivo using an inversion-recovery fast gradient-echo sequence and 3-tesla MR imaging unit. We also measured hematocrit (Hct) values of venous blood samples. After nonselective application of the inversion pulse using a body coil, we obtained MR imaging signals of arterial blood in the abdominal aorta. Similarly, we measured the signals of venous blood in the internal jugular vein. Inversion times varied between 200 and 5000 ms for imaging of the abdominal aorta and 200 and 2500 ms for imaging of the jugular vein. We also acquired signals without the inversion pulse. We estimated T-1 values from the data by nonlinear least squares fitting of a 3-parameter model. Results: The T-1 value (mean +/- standard deviation) of arterial blood was 1779 +/- 80 ms and of venous blood, 1694 +/- 77 ms. The average Hct value was 0.47. The R-1 (=1/T-1) of arterial blood was related to the Hct value as: R-1 = (0.59 +/- 0.16)Hct + (0.29 +/- 0.07) (meant +/- standard error) s(-1). For the venous blood, R-1 = (0.70 +/- 0.11)Hct + (0.27 +/- 0.05)s(-1). Conclusion: We observed a T-1 of human arterial blood in vivo of 1779 +/- 80 ms at a mean hematocrit value of 0.47 as determined by 3T MR imaging; an even longer T-1 value is expected with a hematocrit value less than 0.47.

  36. Positron emission tomography inter-scanner differences in dopamine D-2 receptor binding measured with [C-11]FLB457 査読有り

    Fumitoshi Kodaka, Hiroshi Ito, Miho Shidahara, Harumasa Takano, Hidehiko Takahashi, Ryosuke Arakawa, Kazuhiko Nakayama, Tetsuya Suhara

    ANNALS OF NUCLEAR MEDICINE 24 (9) 671-677 2010年11月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s12149-010-0407-5  

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    It is well known that the positron emission tomography (PET) system is subject to inter-scanner differences of regional radioactivity distribution. In the present study, the effect of inter-scanner difference of regional radioactivity on estimated binding potential (BPND) of [C-11]FLB457 using the simplified reference tissue model (SRTM) was investigated. Each of the 11 subjects was given two PET scans using [C-11]FLB457, one each with both SET-3000 GCT/X (Shimadzu) and with ECAT EXACT HR+ (Siemens/CTI). In order to assess regional differences between the two scanners, estimated BPND values in six volumes of interest (VOIs) by SRTM method were compared in both individual PET space and anatomical template space after anatomical normalization. Statistical voxel-by-voxel paired t test of BPND images between SET-3000 GCT/X and ECAT EXACT HR+ was also performed. Shapes of time-activity curves of the two PET scanners were slightly different in each VOI, with estimated BPND values from ECAT EXACT HR+ appearing greater in the cerebral cortical regions and thalamus than that of SET-3000 GCT/X in both individual PET space and anatomical template space after anatomical normalization. Statistical voxel-by-voxel analysis showed similar tendency to BPND value estimation, with greater BPND values from ECAT EXACT HR+ than from SET-3000 GCT/X. We demonstrated the inter-scanner differences in dopamine D-2 receptor binding measured with [C-11]FLB457. In particular, statistically significant differences of BPND in certain regions were observed between two PET scanners, despite the subject groups being the same. Our results suggest that we reconsider the effect of the scanner model on the measurement of receptor binding.

  37. Quantitative analysis of dopamine transporters in human brain using [C-11]PE2I and positron emission tomography: evaluation of reference tissue models 査読有り

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

    ANNALS OF NUCLEAR MEDICINE 24 (4) 249-260 2010年5月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s12149-010-0364-z  

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

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

  38. Measurement error analysis for the determination of dopamine D-2 receptor occupancy using the agonist radioligand [C-11]MNPA 査読有り

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

    JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM 30 (1) 187-195 2010年1月

    出版者・発行元:NATURE PUBLISHING GROUP

    DOI: 10.1038/jcbfm.2009.193  

    ISSN:0271-678X

    詳細を見る 詳細を閉じる

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

  39. A new graphic plot analysis for determination of neuroreceptor binding in positron emission tomography studies 査読有り

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

    NEUROIMAGE 49 (1) 578-586 2010年1月

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.neuroimage.2009.07.021  

    ISSN:1053-8119

    詳細を見る 詳細を閉じる

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

  40. 卵巣癌に対するS-1およびL-OHPの抗腫瘍効果の比較検討 査読有り

    地元 佑輔, 仲田 栄子, 駒村 一樹, 長澤 陽介, 渡邊 重明, 齋藤 春夫, 森 一生, 田村 元, 町田 好男, 石橋 忠司, 千田 浩一, 志田原 美保, 小山内 実, 小倉 隆英, 細貝 良行, 川住 祐介, 土橋 卓, 高井 良尋

    東北大学医学部保健学科紀要 19 (2) 107-115 2010年

    出版者・発行元:東北大学医学部保健学科

    ISSN:1348-8899

  41. No regional difference in dopamine D-2 receptor occupancy by the second-generation antipsychotic drug risperidone in humans: a positron emission tomography study 査読有り

    Hiroshi Ito, Ryosuke Arakawa, Hidehiko Takahashi, Harumasa Takano, Masaki Okumura, Tatsui Otsuka, Yoko Ikoma, Miho Shidahara, Tetsuya Suhara

    INTERNATIONAL JOURNAL OF NEUROPSYCHOPHARMACOLOGY 12 (5) 667-675 2009年6月

    出版者・発行元:CAMBRIDGE UNIV PRESS

    DOI: 10.1017/S1461145708009577  

    ISSN:1461-1457

    詳細を見る 詳細を閉じる

    The effects of antipsychotic drugs have generally been considered to be mediated by blockade of dopamine D-2 receptors. The concept of limbic and cortical selectivity of second-generation antipsychotics, i.e. higher dopamine D-2 receptor occupancy in the cerebral cortices than in the striatum, has been Suggested to explain their clinical efficacy with lower incidence of extrapyramidal side-effects. In this study, regional distribution of dopamine D-2 receptor occupancy by risperidone was determined in order to elucidate the limbic and cortical selectivity of second-generation antipsychotics. Striatal and extrastriatal dopamine D-2 receptor binding at baseline and after oral administration of 2 mg risperidone were measured in ten healthy men by positron emission tomography (PET) using different tracers with different affinity for the receptors, [C-11]raclopride and [C-11]FLB 457, respectively. Striatal and extrastriatal occupancies of dopamine D-2 receptors were calculated for each brain region. Occupancies of dopamine D-2 receptors were about 70%, and 60% in the striatum and extrastriatum, respectively. A simulation study showed that non-negligible specific binding in the reference region (cerebellum), could cause systemic underestimation of occupancy in [C-11]FLB 457 PET studies, indicating that occupancies in both the striatum and extrastriatum may not have differed. Among the extrastriatal regions including limbic and neocortical regions, no significant regional differences in dopamine D receptor occupancy were observed. Thus, limbic and cortical selectivity was not observed by one of the second-generation antipsychotics, risperidone.

  42. Improvement of likelihood estimation in Logan graphical analysis using maximum a posteriori for neuroreceptor PET imaging 査読有り

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

    ANNALS OF NUCLEAR MEDICINE 23 (2) 163-171 2009年2月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s12149-008-0226-0  

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    To reduce variance of the total volume of distribution (V (T)) image, we improved likelihood estimation in graphical analysis (LEGA) for dynamic positron emission tomography (PET) images using maximum a posteriori (MAP). In our proposed MAP estimation in graphical analysis (MEGA), a set of time-activity curves (TACs) was formed with V (T) varying in physiological range as a template, and then the most similar TAC was sought out for a given measured TAC in a feature space. In simulation, MEGA was compared with other three methods, Logan graphical analysis (GA), multilinear analysis (MA1), and LEGA using 500 noisy TACs, under each of seven physiological conditions (from 9.9 to 61.5 of V (T)). PET studies of [(11)C]SA4503 were performed in three healthy volunteers. In clinical studies, the V (T) images estimated from MEGA were compared with region of interest (ROI) estimates from a nonlinear least square (NLS) fitting over four brain regions. In the simulation study, the estimated V (T) by GA had a large underestimation (y = 0.27x + 8.72, r (2) = 0.87). Applying the other methods (MA1, LEGA, and MEGA), these noise-induced biases were improved (y = 0.80x + 4.04, r (2) = 0.98; y = 0.85x + 3.05, r (2) = 0.99; y = 0.96x + 1.21, r (2) = 0.99, respectively). MA1 and LEGA produced increased variance of the estimated V (T) in clinical studies. However, MEGA improved signal-to-noise ratio (SNR) in V (T) images with linear correlations between ROI estimates with NLS (y = 0.87x + 5.1, r (2) = 0.96). MEGA was validated as an alternative strategy of LEGA to improve estimates of V (T) in clinical PET imaging.

  43. Functional and structural synergy for resolution recovery and partial volume correction in brain PET 査読有り

    Miho Shidahara, Charalampos Tsoumpas, Alexander Hammers, Nicolas Boussion, Dimitris Visvikis, Tetsuya Suhara, Iwao Kanno, Federico E. Turkheimer

    NEUROIMAGE 44 (2) 340-348 2009年1月

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.neuroimage.2008.09.012  

    ISSN:1053-8119

    eISSN:1095-9572

    詳細を見る 詳細を閉じる

    Purpose: Positron Emission Tomography (PET) has the unique capability of measuring brain function but its clinical potential is affected by low resolution and lack of morphological detail. Here we propose and evaluate a wavelet synergistic approach that combines functional and structural information from a number of sources (CT, MRI and anatomical probabilistic atlases) for the accurate quantitative recovery of radioactivity concentration in PET images. When the method is combined with anatomical probabilistic atlases, the outcome is a functional volume corrected for partial volume effects. Methods: The proposed method is based on the multiresolution property of the wavelet transform. First, the target PET image and the corresponding anatomical image (CT/MRI/atlas-based segmented MRI) are decomposed into several resolution elements. Secondly, high-resolution components of the PET image are replaced, in part, with those of the anatomical image after appropriate scaling. The amount of structural input is weighted by the relative high frequency signal content of the two modalities. The method was validated on a digital Zubal phantom and clinical data to evaluate its quantitative potential. Results: Simulation studies showed the expected relationship between functional recovery and the amount of correct structural detail provided, with perfect recovery achieved when true images were used as anatomical reference. The use of T1-MRI images brought significant improvements in PET image resolution. However improvements were maximized when atlas-based segmented images as anatomical references were used; these results were replicated in clinical data sets. Conclusion: The synergistic use of functional and structural data, and the incorporation of anatomical probabilistic information in particular, generates morphologically corrected PET images of exquisite quality. (C) 2008 Elsevier Inc. All rights reserved.

  44. Optimal scan time of oxygen-15-labeled gas inhalation autoradiographic method for measurement of cerebral oxygen extraction fraction and cerebral oxygen metabolic rate 査読有り

    Miho Shidahara, Hiroshi Watabe, Kyeong Min Kim, Nobuyuki Kudomi, Hiroshi Ito, Hidehiro Iida

    ANNALS OF NUCLEAR MEDICINE 22 (8) 667-675 2008年10月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s12149-008-0157-9  

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    Regional cerebral blood flow (CBF), cerebral blood volume, oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2) can be estimated from C15O, H-2 15O, and 15O(2) tracers and positron emission tomography (PET) using an autoradiographic (ARG) method. Our objective in this study was to optimize the scan time for 15O(2) gas study for accurate estimation of OEF and CMRO2. We evaluated statistical noise in OEF by varying the scan time and error caused by the tissue heterogeneity in estimated OEF and CMRO2 using computer simulations. The characteristics of statistical noise were investigated by signal-to-noise (S/N) ratio from repeated tissue time activity curves with noise, which were generated using measured averaged arterial input function and assuming CBF = 20, 50, and 80 (ml/100 g per minute). Error caused by tissue heterogeneity was also investigated by estimated OEF and CMRO2 from tissue time activity curve with mixture of gray and white matter varying fraction of mixture. In the simulations, three conditions were assumed (i) CBF in gray and white matter (CBFg and CBFw) was 80 and 20, OEF in gray and white matter (E g and E w) was 0.4 and 0.3, (ii) CBFg and CBFw decreased by 50%, and E g and E w increased by 50% when compared with conditions (i) and (iii). CBFg and CBFw decreased by 80%, and E g and E w increased by 50% when compared with condition (i). The longer scan time produced the better S/N ratio of estimated OEF value from three CBF values (20, 50, and 80). Errors of estimated OEF for three conditions owing to tissue heterogeneity decreased, as scan time took longer. Meanwhile in the case of CMRO2, 3 min of scan time was desirable. The optimal scan time of 15O(2) inhalation study with the ARG method was concluded to be 3 min from taking into account for maintaining the S/N ratio and the quantification of accurate OEF and CMRO2.

  45. Error analysis for PET measurement of dopamine D(2) receptor occupancy by antipsychotics with [(11)C]raclopride and [(11)C]FLB 457 査読有り

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

    NEUROIMAGE 42 (4) 1285-1294 2008年10月

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.neuroimage.2008.05.056  

    ISSN:1053-8119

    詳細を見る 詳細を閉じる

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

  46. Wavelet denoising for voxel-based compartmental analysis of peripheral benzodiazepine receptors with F-18-FEDAA1106 査読有り

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

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 35 (2) 416-423 2008年2月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s00259-007-0623-y  

    ISSN:1619-7070

    詳細を見る 詳細を閉じる

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

  47. Body-contour versus circular orbit acquisition in cardiac SPECT: Assessment of defect detectability with channelized Hotelling observer 査読有り

    Antti Sohlberg, Hiroshi Watabe, Miho Shidahara, Hidehiro Lida

    NUCLEAR MEDICINE COMMUNICATIONS 28 (12) 937-942 2007年12月

    出版者・発行元:LIPPINCOTT WILLIAMS & WILKINS

    DOI: 10.1097/MNM.0b013e3282f1b9a3  

    ISSN:0143-3636

    詳細を見る 詳細を閉じる

    Background The resolution of a gamma camera is depth-dependent and worsens with increasing distance to the camera resulting in a loss of fine details in SPECT images. A common approach to reduce the effects of this resolution loss is to utilize body-contour acquisition orbits. Even though body-contour orbits can improve resolution of reconstructed images their effect on lesion detection is not well known. Objective To investigate whether body-contour orbits offer better defect detection performance than circular orbits in cardiac SPECT. Methods The mathematical cardiac torso (MCAT) phantom was used to model Tc-99m-sestamibi uptake. A total of four phantoms (two male and two female) with eight defects (four locations and two sizes) were generated and projection data were simulated using an analytical projector with attenuation, scatter, collimator response and acquisition orbit modelling. The circular and body-contour projections were reconstructed using the OSEM algorithm with/without collimator response compensation. Defect detection performance was assessed by calculating area under the receiver operating characteristic (ROC) curve for channelized Hotelling observer. Results The defect detection performance of circular and body-contour acquisition was very similar and the difference in the area under the ROC curve between the orbits was not statistically significant with or without collimator response compensation. The collimator response compensation, on the other hand, was noticed to be valuable and it provided significantly better defect detection performance than reconstruction without it regardless of the acquisition orbit type. Conclusions We conclude that by replacing circular orbit with more complex body-contour orbit will not lead to statistically significant increase in defect detection performance in cardiac SPECT.

  48. Mapping of central dopamine synthesis in man, using positron emission tomography with L-[beta-C-11]DOPA 査読有り

    Hiroshi Ito, Miho Shidahara, Harurnasa Takano, Hidehiko Takahashi, Shoko Nozaki, Tetsuya Suhara

    ANNALS OF NUCLEAR MEDICINE 21 (6) 355-360 2007年8月

    出版者・発行元:JAPANESE SOCIETY NUCLEAR MEDICINE

    DOI: 10.1007/s12149-007-0033-z  

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    Objective To estimate the presynaptic function of the central dopaminergic system, positron emission tomography measurement of the endogenous dopamine synthesis rate was performed with L-[beta-C-11]DOPA. In the present study, we developed a simple method for calculating an indicator of the dopamine synthesis rate with L-[beta-C-11]DOPA on a voxel-by-voxel basis for parametric mapping. Methods After intravenous injection Of L-[beta-C-11]DOPA, dynamic scanning was performed on ten healthy men for 89 min. The dopamine synthesis ratio was calculated on a voxel-by-voxel basis as the ratio of the area under the time-activity curves of brain regions to the reference brain region, that is, occipital cortex. The overall uptake rate constant as an indicator of dopamine synthesis was also calculated by kinetic and graphical analyses. Results The dopamine synthesis ratio calculated by the present method was in good agreement with the indicators of dopamine synthesis calculated by kinetic and graphical analyses, although a systemic underestimation was observed, especially when the integration interval was set in the early phase of the scan duration. In particular, underestimations were prominent in brain regions with relatively lower influx rate constant K-1. Conclusions By this method, regional dopamine synthesis could be estimated on a voxel-by-voxel basis. This method does not need an arterial input function and should prove to be useful for clinical research.

  49. 高齢健常人におけるbaPWVと脳の形態変化との相関

    大沢 伸一郎, 瀧 靖之, 後藤 了以, 佐藤 和則, 井上 健太郎, 岡田 賢, 内田 信也, 志田原 美保, 木之村 重男, 福田 寛

    Radiation Medicine 25 (Suppl.I) 29-29 2007年4月

    出版者・発行元:(公社)日本医学放射線学会

    ISSN:0288-2043

    eISSN:1862-5274

  50. Omission of serial arterial blood sampling for quantitative analysis of monkey PET data using independent component analysis-based method 査読有り

    Mika Naganawa, Hideo Tsukada, Hiroyuki Ohba, Kiichi Ishiwata, Chie Seki, Miho Shidahara, Yuichi Kimura

    IEEE Nuclear Science Symposium Conference Record 6 4510-4512 2007年

    DOI: 10.1109/NSSMIC.2007.4437112  

    ISSN:1095-7863

    詳細を見る 詳細を閉じる

    Serial arterial blood sampling is required to measure a blood input function in quantitative estimation of physiological parameters in dynamic positron emission tomography (PET) studies. However, blood sampling is problematic for animal PET study due to limited amount of blood allowed. Therefore, it is of interest to obviate arterial blood sampling. We have previously proposed a method for estimating a blood input curve based on independent component analysis in human study. In this paper, we applied the method to monkey [18F]fluorodeoxyglucose studies, and validated its applicability by comparing the estimated regional cerebral metabolic rates of glucose using the estimated and the measured blood input function. Experimental results suggest that the proposed method enables quantitative analysis in PET without serial arterial blood sampling not only in human data but also in monkey data. ©2007 IEEE.

  51. Development of a digital phantom for evaluation of fundamental performance on SPECT 査読有り

    Nobutoku Motomura, Koichi Ogawa, Miho Shidahara, Hideo Onishi

    IEEE Nuclear Science Symposium Conference Record 6 4524-4527 2007年

    DOI: 10.1109/NSSMIC.2007.4437115  

    ISSN:1095-7863

    詳細を見る 詳細を閉じる

    We have developed digital phantoms to be used for a basic education on an image quality and a quantification of SPECT data. Differing from the digital phantoms developed by Castiglioni and et al, several SPECT projection data sets were generated by Monte Carlo simulations (EGS4 code) with different acquisition parameters. A physical, brain and cardiac phantoms were generated. An external shape of the physical phantom is a 200 mm diameter and 200 mm long cylinder. Three objects, each of which consists of 4 mm, 10 mm, 20 mm, 40 mm and 60 mm diameter rods (each rod is 30 mm long) , are set in. Shapes of the brain phantom were created using a MRI data set. Shapes of the cardiac phantom were created using a CT image set. Tc-99m was used for the simulations. The Monte Carlo simulations were performed, taking account of Compton scattering, photoelectric effect and degradation of a spatial resolution due to collimator aperture. SPECT acquisition parameters were collimator type, pixel length, acquired photon count, projection number and radius of detector rotation. Ideal SPECT projection data and transaxial image were generated as reference (standard) data. Several attenuation maps with different attenuation coefficients can be used for an evaluation of an attenuation correction. The triple energy window setting was used for an evaluation of a scatter correction such as the TEW method. Overall, primary and scattered photons were saved in different files. By using the proposed phantoms, spatial resolution, contrast, signal to noise ratio and quantification with SPECT data acquisition and processing parameters were evaluated. The phantoms are considered to be useful for understanding the fundamental performance on SPECT. ©2007 IEEE.

  52. Evaluation of optimal scan time by bootstrap approach for quantitative analysis in PET receptor study 査読有り

    Yoko Ikoma, Miho Shidahara, Hiroshi Ito, Chie Seki, Tetsuya Suhara, Iwao Kanno

    IEEE Nuclear Science Symposium Conference Record 4 2131-2133 2007年

    DOI: 10.1109/NSSMIC.2006.354335  

    ISSN:1095-7863

    詳細を見る 詳細を閉じる

    Quantification of the receptor binding potential (BP) in human brain has been performed with positron emission tomography. In this quantitative analysis, the uncertainty in estimated kinetic parameters depends on the SNR. Evaluation of the reliability of parameter estimates is important for the optimization of scan protocol and quantitative analysis methods. However, estimating the reliability is not easy for human data because the true noise level is not precisely known. In this study, we have evaluated a method for estimating the reliability of kinetic parameters with a bootstrap approach for both simulated and human data, and applied this method to evaluating the influence of scan time on the error in BP estimated from PET [11C]raclopride studies. As a result, it was possible to deduce the reliability of kinetic parameter estimates in region-of-interest analysis of human data using the replicated data generated by bootstrap method. In [11C]raclopride studies, the mean estimated BP value did not change when the scan time decreased from 90 to 15 min. However, the uncertainty in BP estimates became larger as the scan time became shorter. With the bootstrap method, it is possible to easily assess the reliability of parameter estimates using only the measured data, and this method can be applied to optimizing scan protocol. © 2006 IEEE.

  53. Quantitative mapping of basal and vasareactive cerebral blood flow using split-dose I-123-iodoamphetamine and single photon emission computed tomography 査読有り

    Kyeong Min Kim, Hiroshi Watabe, Takuya Hayashi, Kohei Hayashida, Tetsuro Katafuchi, Naoyuki Enomoto, Toshiyuki Ogura, Miho Shidahara, Shugo Takikawa, Stefan Eberl, Mayumi Nakazawa, Hidehiro Iida

    NEUROIMAGE 33 (4) 1126-1135 2006年12月

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.neuroimage.2006.06.064  

    ISSN:1053-8119

    詳細を見る 詳細を閉じる

    A new method has been developed for diffusible tracers, to quantify CBF at rest and after pharmacological stress from a single session of dynamic scans with dual bolus administration of a radiotracer. The calculation process consisted of three steps, including the procedures of incorporating background radioactivity contaminated from the previous scan. Feasibility of this approach was tested on clinical SPECT studies on 16 subjects. Two sequential SPECT scans, 30 min apart, were carried out on each subject, after each of two split-dose administrations of 111 MBq IMP. Of these, 11 subjects received acetazolamide at 10 min before the second IMP injection. Additional PET scans were also carried out on 6 subjects on a separate day, at rest and after acetazolamide administration. The other 5 subjects were scanned only at rest during the whole study period. Quantitative CBF obtained by this method was in a good agreement with those determined with PET (gamma(ml/100 g/min)= 1.07 x (ml/100 g/min) -1.14, r=0.94). Vasareactivity was approximately 40% over the whole cerebral area on healthy controls, which was consistent with a literature value. Reproducibility of CBF determined in the rest-rest study was 1.5 +/- 5.7%. Noise enhancement of CBF images, particularly the second CBF, was reduced, providing reasonable image quality. Repeat assessment of quantitative CBF from a single session of scans with split-dose IMP is accurate, and may be applied to clinical research for assessing vascular reactivity in patients with chronic cerebral vascular disease. (c) 2006 Elsevier Inc. All rights reserved.

  54. 高齢健常人におけるbaPWVと脳の形態変化との相関

    大沢 伸一郎, 瀧 靖之, 後藤 了以, 佐藤 和則, 井上 健太郎, 岡田 賢, 内田 信也, 志田原 美保, 木之村 重男, 福田 寛

    核医学 43 (4) 340-340 2006年11月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  55. Predicting human performance by channelized Hotelling observer in discriminating between Alzheimer's dementia and controls using statistically processed brain perfusion SPECT 査読有り

    Miho Shidahara, Kentaro Inoue, Masahiro Maruyama, Hiroshi Watabe, Yasuyuki Taki, Ryoi Goto, Ken Okada, Shigeo Kinomura, Shinichiro Osawa, Yoshimi Onishi, Hiroshi Ito, Hiroyuki Arai, Hiroshi Fukuda

    ANNALS OF NUCLEAR MEDICINE 20 (9) 605-613 2006年11月

    出版者・発行元:JAPANESE SOCIETY NUCLEAR MEDICINE

    DOI: 10.1007/BF02984658  

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    Objective: We compared the diagnostic accuracy achieved by a human observer (nuclear medicine physician) and a channelized Hotelling (CH) observer on the basis of receiver-operating characteristics (ROC) curve for the differential diagnosis of Alzheimer's disease (AD) from SPECT images. Methods: The I-123-IMP brain perfusion SPECT images of 42 subjects (21 AD patients and 21 healthy controls) were used for an interpretation study and those of 10 healthy subjects were for a normal database. SPECT images were processed into four types: original SPECT images, three-dimensional stereotactic surface projection (3DSSP) images derived from them, Z-scores of SPECT images, and Z-scores of 3DSSP images. Five nuclear medicine physicians evaluated the test dataset sequentially as to whether the presented images were those of AD patients, which were rated using five categories of certainty: definitely, possibly, equivocally, possibly not, and definitely not. The test statistics (.) of the dataset generated by the CH observer were rated for ROC analysis. The areas under the ROC curves (Az) for the four image types interpreted by the human and CH observers were estimated and compared. Results: Among the four image types, the best performance based on Az obtained by both the CH and human observers was observed for the Z-score of 3DSSP images, and the lowest was for the original SPECT images. Conclusions: The performance of the CH observer was similar to that of the human observers, and both were dependent on the image type. This indicates that the CH observer may predict human performance in discriminating Alzheimer's dementia and can be useful for comparing and optimizing image processing methods of brain perfusion SPECT without human observers.

  56. Brain and whole body distribution of N-isopropyl-4-iodoamphetamine (I-123) in humans: Comparison of radiopharmaceuticals marketed by different companies in Japan 査読有り

    Hiroshi Ito, Tachio Sato, Hayato Odagiri, Kentaro Inoue, Miho Shidahara, Tetsuya Suhara, Jun Hatazawa, Hiroshi Fukuda

    ANNALS OF NUCLEAR MEDICINE 20 (7) 493-498 2006年8月

    出版者・発行元:JAPANESE SOCIETY NUCLEAR MEDICINE

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    Objective: Iodine-123 (I-123)-Iabeled N-isopropyl-4-iodoamphetamine (IMP) has been used as a cerebral blood flow (CBF) tracer for single-photon emission computed tomography (SPECT). An autoradiographic (ARG) method has been developed for the quantitation of CBF by IMP and SPECT. Two IMPs (IMPA and IMPB) produced by different radiopharmaceutical companies are marketed in Japan. In the present study, whole-body distributions including brain and blood of the two IMPs were compared in the same human subjects. Methods: Two brain SPECT studies using IMPA or IMPB were performed on separate days in six young healthy men. Whole-body scans were also obtained with a large field-of-view single-head gamma camera. One-point arterial blood sampling was performed at 10 min after injection of IMP to measure both the radioactivity concentrations of whole blood and of octanol-extracted components. Results: No significant differences between the two tracers were observed in body distribution, tracer kinetics in brain, or regional distribution in brain. However, the octanol extraction fraction in blood was significantly different between the two tracers. Radiochemical purity was slightly but significantly different between the tracers. Conclusions: In the ARG method, arterial input function is determined by calibration of a standard input function with the radioactivity concentration of arterial whole blood. Because the standard input function in the ARG method was obtained using IMPA, the standard input function obtained for IMPB should be used when CBF is calculated by the ARG method with IMPB.

  57. Database of normal human cerebral blood flow measured by SPECT: II. Quantification of I-123-IMP studies with ARG method and effects of partial volume correction 査読有り

    K Inoue, H Ito, M Shidahara, R Goto, S Kinomura, K Sato, Y Taki, K Okada, T Kaneda, H Fukuda

    ANNALS OF NUCLEAR MEDICINE 20 (2) 139-146 2006年2月

    出版者・発行元:JAPANESE SOCIETY NUCLEAR MEDICINE

    DOI: 10.1007/BF02985626  

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    The limited spatial resolution of SPECT causes a partial volume effect (PVE) and can lead to the significant underestimation of regional tracer concentration in the small structures surrounded by a low tracer concentration, such as the cortical gray matter of an atrophied brain. The aim of the present study was to determine, using I-123-IMP and SPECT, normal CBF of elderly subjects with and without PVE correction (PVC), and to determine regional differences in the effect of PVC and their association with the regional tissue fraction of the brain. Methods: Quantitative CBF SPECT using I-123-IMP was performed in 33 healthy elderly subjects (18 males, 15 females, 54-74 years old) using the autoradiographic method. We corrected CBF for PVE using segmented MR images, and analyzed quantitative CBF and regional differences in the effect of PVC using tissue fractions of gray matter (GM) and white matter (WM) in regions ofinterest (ROls) placed on the cortical and subcortical GM regions and deep WM regions. Results: The mean CBF in GM-ROIs were 31.7 +/- 6.6 and 41.0 +/- 8.1 ml/100 g/min for males and females, and in WM-ROIs, 18.2 +/- 0.7 and 22.9 +/- 0.8 ml/100 g/min for males and females, respectively. The mean CBF in GM-ROIs after PVC were 50.9 +/- 12.8 and 65.8 +/- 16.1 ml/100 g/min for males and females, respectively. There were statistically significant differences in the effect of PVC among ROIs, but not between genders. The effect of PVC was small in the cerebellum and parahippocampal gyrus, and it was large in the superior frontal gyrus, superior parietal lobule and precentral gyrus. Conclusion: Quantitative CBF in GM recovered significantly, but did not reach values as high as those obtained by invasive methods or in the (H2O)-O-15 PET study that used PVC. There were significant regional differences in the effect of PVC, which were considered to result from regional differences in GM tissue fraction, which is more reduced in the frontoparietal regions in the atrophied brain of the elderly.

  58. Evaluation of Optimal Scan Time by Bootstrap Approach for Quantitative Analysis in PET Receptor Study 査読有り

    Yoko Ikoma, Miho Shidahara, Hiroshi Ito, Chie Seki, Tetsuya Suhara, Iwao Kanno

    2006 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOL 1-6 2131-2133 2006年

    出版者・発行元:IEEE

    ISSN:1082-3654

    詳細を見る 詳細を閉じる

    Quantification of the receptor binding potential (BP) in human brain has been performed with positron emission tomography. In this quantitative analysis, the uncertainty in estimated kinetic parameters depends on the SNR. Evaluation of the reliability of parameter estimates is important for the optimization of scan protocol and quantitative analysis methods. However, estimating the reliability is not easy for human data because the true noise level is not precisely known. In this study, we have evaluated a method for estimating the reliability of kinetic parameters with a bootstrap approach for both simulated and human data, and applied this method to evaluating the influence of scan time on the error in BP estimated from PET [(11)C]raclopride studies. As a result, it was possible to deduce the reliability of kinetic parameter estimates in region-of-interest analysis of human data using the replicated data generated by bootstrap method. In [(11)C] raclopride studies, the mean estimated BP value did not change when the scan time decreased from 90 to 15 min. However, the uncertainty in BP estimates became larger as the scan time became shorter. With the bootstrap method, it is possible to easily assess the reliability of parameter estimates using only the measured data, and this method can be applied to optimizing scan protocol.

  59. Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method 査読有り

    M Shidahara, H Watabe, KM Kim, T Kato, S Kawatsu, R Kato, K Yoshimura, H Iida, K Ito

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 32 (10) 1193-1198 2005年10月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s00259-005-1791-2  

    ISSN:1619-7070

    詳細を見る 詳細を閉じる

    Purpose: An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with Tc-99m-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. Methods: The IBSC method corrects scatter on the reconstructed image I-AC(mu b) with Chang's attenuation correction factor. The scatter component image is estimated by convolving I-AC(mu b) with a scatter function followed by multiplication with an image- based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and Tc-99m-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Results: Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. Conclusion: The IBSC method is a simple scatter correction technique feasible for use in clinical routine.

  60. Effects of tissue heterogeneity on cerebral vascular response to acetazolamide stress measured by an I-123-IMP autoradiographic method with single-photon emission computed tomography 査読有り

    H Ito, M Shidahara, K Inoue, R Goto, S Kinomura, Y Taki, K Okada, T Kaneta, K Sato, T Sato, H Fukuda

    ANNALS OF NUCLEAR MEDICINE 19 (4) 251-260 2005年6月

    出版者・発行元:JAPANESE SOCIETY NUCLEAR MEDICINE

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    Objectives: Single-photon emission computed tomography (SPECT) with iodine-123 (I-123)-labeled N-isopropyl-p-iodoamphetamine (IMP) is widely used in measuring the cerebral blood flow (CBF) response to acetazolamide stress for assessment of cerebral vascular reserve. To quantitate CBF by means of SPECT with IMP, an autoradiographic (ARG) method has been developed and is widely used. Because the relation between the brain counts on the SPECT scan and CBF is not linear in the ARG method, a mixture of gray and white matter in a pixel causes errors in the calculation of CBF. In the present study, errors in the calculation of CBF and vascular response to acetazolamide stress by the ARG method due to tissue heterogeneity were estimated by simulation study. Correction for effects of tissue heterogeneity in SPECT data was also attempted. Methods: Images of gray and white matter fraction were obtained by voxel-based morphometry analysis of magnetic resonance (MR) imaging data set. Ideal CBF images, which were generated from gray and white matter fraction images with assumed blood flow values for gray and white matter, were compared to CBF images generated by the ARG method. Correction for effects of tissue heterogeneity in SPECT data was per-formed with gray and white matter fraction data obtained from MR images. Results: Systematic underestimation of CBF due to tissue heterogeneity was observed in all brain regions. In the neocortical regions, underestimation by -21% to -16%, -26% to -20%, -31% to -24%, and -35% to -27% was observed for gray and white matter blood flow of 80 and 20, 100 and 25, 120 and 30, and 140 and 35 ml/100 ml/min, respectively. Vascular response was also systematically underestimated in most brain regions. Vascular responses in the neocortical regions ranged from 17% to 20%, from 31% to 37%, and from 42% to 52% when ideal vascular responses were 25%, 50%, and 75%, respectively. After correction for the effects of tissue heterogeneity, values of vascular response to acetazolamide stress ranged from 64% to 116% in the neocortical regions, whereas values obtained by the ARG method ranged from 48% to 52%. Conclusion: Underestimation of the vascular response to acetazolamide stress due to tissue heterogeneity should be considered in the estimation of cerebral vascular reserve.

  61. A comparison of human observers and a channelized hotelling observer in discriminating between Alzheimer's Dementia and controls using brain perfusion SPECT 査読有り

    Miho Shidahara, Kentaro Inoue, Masahiro Maruyama, Yasuyuki Taki, Ryoi Goto, Ken Okada, Shichiro Osawa, Shigeo Kinomura, Hiroshi Ito, Hiroyuki Arai, Hiroshi Fukuda

    IEEE Nuclear Science Symposium Conference Record 4 2148-2149 2005年

    DOI: 10.1109/NSSMIC.2005.1596759  

    ISSN:1095-7863

  62. A comparison of human observers and a channelized hotelling observer in discriminating between Alzheimer's dementia and controls using brain perfusion SPECT 査読有り

    Miho Shidahara, Kentaro Inoue, Masahiro Maruyama, Yasuyuki Taki, Ryoi Goto, Ken Okada, Shinichiro Osawa, Shigeo Kinomura, Hiroshi Ito, Hiroyuki Arai, Hiroshi Fukuda

    2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 2148-2149 2005年

    出版者・発行元:IEEE

    ISSN:1082-3654

  63. Development of image-based scatter correction for brain perfusion SPECT study: Comparison with TEW method 査読有り

    M Shidahara, H Watabe, KM Kim, S Kawatsu, T Kato, H Iida

    2003 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-5 2652-2656 2004年

    出版者・発行元:IEEE

    ISSN:1082-3654

    詳細を見る 詳細を閉じる

    In order to convert scatter uncorrected into corrected SPECT image, an image-based scatter correction (IBSC) method has been developed. The aim of this study was validation of its role as image converter from scatter uncorrected into corrected images equivalent to image corrected by conventional TEW method. IBSC method is executed in the post-reconstruction process and only requires an attenuation corrected main photo-peak image with broad mu value, I-AC(mub). The scatter component image is estimated by convolving I-AC(mub) with a scatter function followed by multiplying with an image-based scatter fraction (SF) function. The IBSC method was evaluated with Monte Carlo simulations and Tc-99m-ECD SPECT human brain perfusion studies obtained from five volunteers. The noise property of the scatter corrected image using IBSC method, I-IBSC was compared with that by TEW method, I-TEW, with simulated brain phantom images. Image contrast between gray with white matter in the human study was also compared between IBSC and TEW method. The global signal-to-noise (S/N) ratio of I-IBSC was decreased to 14% compared to that of I-AC(mub), whereas that of I-TEW was decreased to 21% In human brain imaging, significant difference in image contrast between IIBSC and TEW method was not observed (p&lt;0.05). In conclusion, the IBSC method could be applied to clinical brain perfusion SPECT as conversion I-AC(mub) into a scatter corrected image equivalent to I-TEW. This achieves a better noise property than the TEW method.

  64. Impact of image-based scatter correction for (IMP)-I-123-SPECT and SPM analysis 査読有り

    M Shidahara, H Watabe, KM Kim, S Kawatsu, R Kato, T Kato, H Iida, K Ito

    QUANTITATION IN BIOMEDICAL IMAGING WITH PET AND MRI (1265) 84-88 2004年

    出版者・発行元:ELSEVIER SCIENCE BV

    DOI: 10.1016/j.ics.2004.04.027  

    ISSN:0531-5131

    詳細を見る 詳細を閉じる

    Recently, techniques for converting site-specific normal databases to other databases have been required for SPECT image statistical analysis. To implement scatter correction, we developed an image conversion technique named image-based scatter correction (IBSC). Furthermore, we evaluated the applicability of IBSC for SPM analysis. SPECT studies were performed on 28 normal volunteers and 10 patients with Alzheimer's disease (AD) using (123) I-IMP. Two sets of scatter uncorrected images, I-AC(mub), and a corrected image by TEW, I-TEW, were reconstructed with attenuation I-AC(mub) correction using Chang's method. Scatter corrected images by IBSC, I-IBSC, were generated from I-AC(mub). Normal databases of I-AC(mub) I-TEW and I-IBSC were compared by SPM analysis. The Z-score (=(mean - AD)/S.D.) Of I-TEW was compared with that of I-AC(mub) Significant differences (p&lt;0.05) between normal databases of I-AC(mub) and I-TEW observed at the global posterior cingulate and precuneus regions almost disappeared when I-TEW and I-IBSC were compared. The Z-score at the posterior cingulate by I-TEW was increased compared with that of I-AC(mub) We conclude that for SPM analysis of IMP-SPECT, IBSC can convert a normal database of scatter uncorrected images into corrected images, which is equivalent to correction by a conventional TEW method. Scatter correction may improve the ability to detect AD. (C) 2004 Elsevier B.V. All rights reserved.

  65. Contribution of scatter and attenuation compensation to SPECT images of nonuniformly distributed brain activities 査読有り

    KM Kim, A Varrone, H Watabe, M Shidahara, M Fujita, RB Innis, H Iida

    JOURNAL OF NUCLEAR MEDICINE 44 (4) 512-519 2003年4月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

    詳細を見る 詳細を閉じる

    Correction of scatter and attenuation is essential for quantitative SPECT. In this work, we evaluated the accuracy gained from a method of transmission-dependent convolution subtraction (TDCS) in the quantitation of activity that is highly concentrated in the striatum (STR). Methods: SPECT data were acquired from an I-123-containing phantom with a constant activity in the STR but differing background (BKG) activities, so as to simulate various STR/BKG ratios (19.7:1, 9.7:1, 4.8:1, 1.9:1, and 1:1). In a study of healthy humans (n = 6), a transmission scan followed by an emission scan was performed 24 h after injection of I-123-2beta-carbomethoxy-3beta-(4-iodophenyl)-tropane (I-123-beta-CIT). All SPECT data was reconstructed with ordered-subset expectation maximization. TDCS was applied for scatter correction. Values of activity in the STR and occipital lobe (for BKG) were used to calculate binding potential V-3" (= [STR - BKG]/BKG). The effect of SPECT collimator dependency on scatter correction was also evaluated for 6 collimators from 3 different SPECT cameras in the phantom experiment. Results: Scatter correction in the phantom experiment increased the measured values of STR activity (36.2%), resulting in a substantial increase in V-3" (66.1%). Scatter and attenuation corrections with recovery correction showed an overall bias of -7.3% for the STR, -4.0% for BKG activity, and -7.8% for V-3". TDCS corrections of phantom activities were relatively uniform for the 6 different collimators, with variabilities of &lt;5.5% for the STR and &lt;3.0% for BKG activities. TDCS correction of human I-123-beta-CIT images was of a similar, although slightly larger, magnitude than for the phantom data, with increased V-3" values of 9.4 +/- 2.3 and 4.9 +/- 0.6, with and without scatter correction, respectively. Conclusion: The TDSC method significantly improved the accuracy of SPECT images with a nonuniform distribution of activity highly concentrated in central regions. The value of V-3" was significantly increased in phantom and human data, with most of the improvement derived from an increase in STR activity. This scatter correction method was approximately equally useful with data from the 6 different collimators and is recommended for more accurate quantitation of nonuniformly distributed brain activities.

  66. Development of a GSO detector assembly for a continuous blood sampling system 査読有り

    N Kudomi, E Choi, S Yamamoto, H Watabe, KM Kim, M Shidahara, M Ogawa, N Teramoto, E Sakamoto, H Iida

    IEEE TRANSACTIONS ON NUCLEAR SCIENCE 50 (1) 70-73 2003年2月

    出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

    DOI: 10.1109/TNS.2002.807869  

    ISSN:0018-9499

    詳細を見る 詳細を閉じる

    A new input function monitoring system has been developed and evaluated using a GSO detector assembly for both PET and SPECT quantitative studies. Energy resolutions were 11% for 511 keV photons, 20% for 140 keV(Tc-99m) photons and 28% for 70 keV(Tl-201) photons, enabling the use of this system in SPECT studies. The paired assembly of crystals provided an absolute sensitivity of approximately 7% for PET tracers and 70% for Tc-99m and Tl-201 (SPECT tracers). Multiple arrangement of paired detectors would make it possible to correct for the transit time of radioactivity through the catheter tube. This study demonstrates that the present system can be of use in both clinical and small animal studies using SPECT and PET tracers.

  67. Simulation study of noise property of CMRO2 quantitation methods with inhalation of O-15(2) 査読有り

    N Kudomi, H Watabe, Y Miyake, KM Kim, M Shidahara, K Hayashida, H Oka, M Sagou, Y Ishida, T Hayashi, H Iida

    2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3 1116-1117 2003年

    出版者・発行元:IEEE

    ISSN:1082-3654

    詳細を見る 詳細を閉じる

    Measurements of the oxygen consumption in brain have been studied by PET. Autoradiographic method(ARG) was suggested (Mintum et al.) to yield CMRO2. This method required separately obtained information about CBF, CBV, thus time of 30-60 min. is required for three separate scans. To decrease the scan time, a new protocol was suggested as a rapid dual table method(ARG-D), in which [O-15]water injection scan and [O-15]O-2 inhalation scan are continuously carried out. Another method of weighted integration(WI) method with single 3 min. O-15(2) inhalation scan was suggested (Ohta et al.). We modified this method by taking into account the water re-circulation(WI-WR). In this study, the statistical noise properties and effects of error propagated from dispersion, delay, and volume of distribution on CMRO2 image, derived by these methods were evaluated. Tissue time activity curves was generated from typical blood time activity curves. A 80 % of noise at a peak in [O-15]water tissue time acticity curve was added to study the noise propagation and accuracy in CMRO2 image. Also dispersion, delay, and volume of distribution was varied and evaluated the error propagation. Methods of ARG, WI-WR and ARG-D, reproduce the given CMRO2 within 2% accuracy, while method WI gives CMRO2 5-15 The effect of noise in unit of %SD was 12 % for ARG, 25 % for WI and WI-WR, and 17 % for ARG-D method. On the basis of simulation study suggests that the ARG-D method developed could be used to estimate the CMRO2 values in clinic.

  68. Evaluation of a commercial PET tomograph-based system for the quantitative assessment of rCBF, rOEF and rCMRO(2) by using sequential administration of O-15-labeled compounds 査読有り

    M Shidahara, H Watabe, KM Kim, H Oka, M Sago, T Hayashi, Y Miyake, Y Ishida, K Hayashida, T Nakamura, H Iida

    ANNALS OF NUCLEAR MEDICINE 16 (5) 317-327 2002年7月

    出版者・発行元:JAPANESE SOCIETY NUCLEAR MEDICINE

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    The purpose of this study was to develop a reliable and practical strategy that generates quantitative CBF and OEF maps accurately from PET data sets obtained with O-15-tracers. Sequential sinogram data sets were acquired after the administration of O-15-tracers, and combined single-frame images were obtained. The de lay time between sampled input function and the brain was estimated from the (H2O)-O-15 study with the whole brain and the arterial time-activity curves (TACs). The whole-brain TACs were obtained from the reconstructed images (image-base method) and the sinogram data (sinogram-base method). Six methods were also evaluated for the dead-time and decay correction procedures in the process of generating a single-frame image from the dynamic sinogram. The estimated delay values were similar with both the sinogram-based and image-based methods. A lumped correction factor to a previously added single-frame sinogram caused an underestimation of CBF, OEF and CMRO2 by 16% at maximum, as compared with the correction procedure for a short sinogram. This suggested the need for a dynamic acquisition of a sinogram with a short interval. The proposed strategy provided an accurate quantification of CBF and OEF by PET with O-15-tracers.

  69. Impact of attenuation and scatter correction in SPECT for quantification of cerebral blood flow using 99mTc-ethyl cysteinate dimer 査読有り

    Miho Shidahara, Hiroshi Watabe, Kyeong Min Kim, Takenori Hachiya, Ichiro Sayama, Iwao Kanno, Takashi Nakamura, Hidehiro Iida

    IEEE Transactions on Nuclear Science 49 (1 I) 5-11 2002年2月

    DOI: 10.1109/TNS.2002.998673  

    ISSN:0018-9499

    詳細を見る 詳細を閉じる

    Attenuation and scatter of photons are the main causes that hinder the quantification of regional cerebral blood flow (rCBF) value by single photon emission computed tomography (SPECT), using 99mTc-Ethyl cysteinate dimer (ECD). We investigated the effects of attenuation correction and scatter correction on rCBF values with 99mTc-ECD SPECT. In particular, the applicability of uniform attenuation maps (μ maps) was evaluated in terms of errors on the estimated CBF values and the optimal threshold levels for extracting brain contours. SPECT scans were performed on seven subjects, in the presence of 99mTc-ECD. Quantitative K 1 images were computed using the reconstructed images and the input function obtained with the frequent arterial blood sampling method. The images were reconstructed by the ordered subset expectation maximization (OSEM) reconstruction in which uniform and segmented μ maps were used for attenuation correction with and without scatter correction. The transmission-dependent convolution subtraction technique was utilized for scatter correction. Segmented and uniform μ maps were generated from magnetic resonance (MR) images. We also produced uniform μ maps using ECD images obtained at various threshold levels and μ values (0.11, 0.15, and 0.172 cm -1). Scatter correction improved the image contrast dramatically. There were no significant differences between K 1 images with attenuation and scatter corrections assuming a uniform μ map (not 0.15 but 0.172 cm -1) and those corrected with segmented μ maps for most regions. However, in the former images, values were overestimated for deep structures (e.g., overestimation of 9.5% in the striatum and 7.3% in the central semi oval). This small but significant error was also observed in phantom studies and Monte Carlo simulations. We show that the overestimation using uniform μ maps is due to the weight of the path length in the bone. Absolute K 1 values were sensitive to the threshold level when the edge of the brain was determined from the ECD images, but the variation of the estimated K 1 was ±9.0% when the optimal threshold level was selected. This study suggests that the use of uniform attenuation μ maps provides reasonable accuracy, despite a small but significant error in deep structure regions, and that uniform μ maps may be provided from the emission data alone in this patient population.

  70. Development of a GSO detector assembly for a continuous blood sampling system 査読有り

    N Kudomi, E Choi, S Yamamoto, H Watabe, KM Kim, M Shidahara, H Iida

    2001 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORDS, VOLS 1-4 1255-1257 2002年

    出版者・発行元:IEEE

    ISSN:1082-3654

    詳細を見る 詳細を閉じる

    A new input function monitoring system has been developed using the GSO detector assembly for both PET and SPECT quantitative studies. Due to the rapid rise time of the pulse (about 10nsec), the coincidence time window can he reduced &lt; 1nsec, reducing contribution of randoms associated with the high background activity surrounding the detector. Large light output improved the energy resolution of approximately 11% for 511keV photons, and 20% at 140 keV, as compared with the BGO detector, enabling the use of this system also in SPECT studies. The paired assembly of crystals provided the absolute sensitivity of approximately 7% for PET and 75% for PET tracers. Multiple arrangement of the paired detectors provided possibility of correcting for the transit time of radioactivity through the catheter tube. This study demonstrated that the present system can be of use in both clinical and small animal studies using SPECT and PET tracers.

  71. SPECT collimator dependency of scatter and validation of transmission-dependent scatter compensation methodologies 査読有り

    Kyeong Min Kim, H. Watabe, M. Shidahara, Y. Ishida, H. Iida

    IEEE Transactions on Nuclear Science 48 (3) 689-696 2001年6月

    DOI: 10.1109/23.940148  

    ISSN:0018-9499

    詳細を見る 詳細を閉じる

    Scatter correction is important for absolute quantification in SPECT. Among the approaches taken to achieve scatter correction, some methods using transmission information for scatter estimation require the scatter models based on the physical characteristics of the scattered photons. The influence of the SPECT collimator on the characteristics of the scattered photon, however, has not been well studied yet. In this paper, we investigate the relationship between scatter and collimator design for the use of the transmission.dependent convolution subtraction (TDCS) method. Monte Carlo simulations with various collimator acceptance angles and experiments with four collimators of two SPECT cameras were performed to obtain the scatter fraction (SF) and the line-spread function (LSF) of Tc-99m. The experiments with I-123 also used six collimators of three SPECT systems to obtain the SF and the LSF. In the simulations, the SF of Tc-99m did not change with the collimator acceptance angles. The LSFs measured for Tc-99m showed an excellent agreement between collimators. In the experiments for I-123, the SF was practically the same for the six collimators, although a small difference could be observed due to the septal penetration. Also, the shape of the LSF was very similar between the collimators, and the counts in the background region of reconstructed images did not differ when using different sets of TDCS parameters. These results reveal that scatter is independent of SPECT collimator design for Tc-99m even I-123, and that the TDCS could be applicable to scatter correction of I-123 using a unique collimator-independent set of parameters.

  72. Noise reduction in PET attenuation correction using non-linear Gaussian filters 査読有り

    K Kitamura, H Iida, M Shidahara, S Miura, Kanno, I

    IEEE TRANSACTIONS ON NUCLEAR SCIENCE 47 (3) 994-999 2000年6月

    出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

    DOI: 10.1109/23.856537  

    ISSN:0018-9499

    詳細を見る 詳細を閉じる

    In a PET study, shortening of transmission scan time is highly desired for improving patient comfort and increasing scanner throughput. It necessitates a method that reduces statistical noise in attenuation correction factors (ACFs). We have evaluated non-linear Gaussian (NLG) filtering for smoothing transmission images reconstructed with filtered back-projection instead of using iterative reconstruction and segmentation methods. The NLG filtering operation is a variation of local weighted averaging in a neighborhood around a pixel, which weights are determined according to both distance in location and difference in pixel value. Several filtering steps with different NLG parameters can effectively reduce noise without losing structural information. The NLG smoothed transmission images are then forward projected to generate ACFs. Results with phantom and patient data suggested that the NLG filtering method is useful for attenuation correction using count-limited transmission data for both brain and whole-body PET studies.

  73. Internal absorbed dose estimation by a TLD method for F-18-FDG and comparison with the dose estimates from whole body PET 査読有り

    HM Deloar, T Fujiwara, M Shidahara, T Nakamura, A Yamadera, M Itoh

    PHYSICS IN MEDICINE AND BIOLOGY 44 (2) 595-606 1999年2月

    出版者・発行元:IOP PUBLISHING LTD

    DOI: 10.1088/0031-9155/44/2/021  

    ISSN:0031-9155

    詳細を見る 詳細を閉じる

    The thermoluminescent dosimeter (TLD) method has been proposed as a useful tool for estimating internal radiation absorbed dose in nuclear medicine. An efficient approach to verify the accuracy of the TLD method has been performed in this study. Under the standard protocol for 2-[F-18]fluoro-2-deoxy-D-glucose (F-18-FDG), whole body PET experiments and simultaneous body surface dose measurements by TLDs were performed on six normal volunteers. By using the body surface dose measured with TLDs, the cumulated activities of nine source organs were estimated with a mathematical unfolding technique for three different initial guesses: The accuracy of the results obtained by the TLD method was investigated by comparison with the actual cumulated activity of the same source organs measured by whole body PET. The cumulated activities of the source organs obtained by the TLD method and whole body PET show a significant correlation (correlation coefficient, r &gt; 0.98, level of confidence, p &lt; 0.001) with each other. The mean effective doses in this study are 3.2 x 10(-2) mSv MBq(-1) obtained from the TLD method and 2.9 x 10(-2) mSv MBq(-1) obtained from the whole body PET. Good agreement between the results of the TLD method and whole body PET was observed.

  74. Validation and optimization of the use of standardized arterial input function in N-isopropyl-p[ 123I]iodoamphetamine cerebral blood flow SPECT 査読有り

    Toshiyuki Ogura, Syugo Takikawa, Hisatoshi Saito, Mayumi Nakazawa, Miho Shidahara, Hidehiro Iida

    Kakuigaku 36 (8) 879-890 1999年

    ISSN:0022-7854

    詳細を見る 詳細を閉じる

    Use of a standardized arterial input function and calibrating it by a single blood sample has been proposed to assess quantitatively cerebral blood flow using N-isopropyl-p[ 123I]iodoamphetamine (IMP) and single-photon emission computed tomography. This study was intended to validate this approach using a larger number of measured arterial radioactivity curves in the clinical setting. Method: Arterial input function was measured for 50 patients at rest following the i.v. IMP, and its inter-subject variation was assessed. Difference between smokers and non-smokers in addition to effects of acetazolamide administration were particularly investigated. We also evaluated the accuracy of the calibration procedures by means of either a single blood sample or a continuous arterial blood withdrawal sampling for an early period. Results: Inter-subject variation of the observed arterial input function appeared not to show large variations among the 50 patients, thus suggesting the validity of using the standardized arterial input function for the IMP SPECT study. There was a significant difference in the shape of the arterial input function between the smokers and non-smokers, but the calibration at an optimized sampling time provided the area-under-the curve (AUC) that was not significantly different between the two groups. The arterial input function after the acetazolamide showed no significant difference as compared with the shape at rest. The calibration of the standardized input function by means of the early integration of individual curve did not show better accuracy except for a short period of AUC (i.e., &lt 20 min) for longer integration period &gt 10 min. Conclusion: Thus, use of the standardized arterial input function has been validated for the IMP SPECT study. The single blood sampling procedure for calibrating the standardized input function has also been validated, and has been shown to provide better accuracy compared with the continuous withdrawal procedure.

  75. Estimation of absorbed dose for 2-[F-18]fluoro-2-deoxy-D-glucose using whole-body positron emission tomography and magnetic resonance imaging 査読有り

    HM Deloar, T Fujiwara, M Shidahara, T Nakamura, H Watabe, Y Narita, M Itoh, M Miyake, S Watanuki

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE 25 (6) 565-574 1998年6月

    出版者・発行元:SPRINGER VERLAG

    DOI: 10.1007/s002590050257  

    ISSN:0340-6997

    詳細を見る 詳細を閉じる

    The purpose of this study was to measure the cumulated activity and absorbed dose in organs after intravenous administration of 2-[F-18]fluoro-2-deoxy-D-glucose (F-18-FDG) using whole-body positron emission tomography (PET) and magnetic resonance imaging (MRI). Whole-body dynamic emission scans for F-18-FDG were performed in six normal volunteers after transmission scans. The total activity of a source organ was obtained from the activity concentration of the organ measured by whole-body PET and the volume of that organ measured by whole-body T1-weighted MRI. The cumulated activity of each source organ was calculated from the time-activity curve. Absorbed doses to the individuals were estimated by the MIRD (medical internal radiation dosimetry) method using S-values adjusted to the individuals. Another calculation of cumulated activities and absorbed doses was performed using the organ volumes from the MIRD phantom and the "Japanese reference man'' to investigate the discrepancy of actual individual results against the phantom results. The cumulated activities of 18 source organs were calculated, and absorbed doses of 27 target organs estimated. Among the target organs, bladder wall, brain and kidney received the highest doses for the above three sets of organ volumes. Using measured individual organ volumes, the average absorbed doses for those organs were found to be 3.1x10(-1), 3.7x10(-2) and 2.8x10(-2) mGy/MBq. respectively. The mean effective doses in this study for individuals of average body weight (64.5 kg) and the MIRD phantom of 70 kg were the same, i.e. 2.9x10(-2) mSv/MBq, while for the Japanese reference man of 60 kg the effective dose was 2.1x10(-2) mSv/MBq, The results for measured organ volumes derived from MRI were comparable to those obtained for organ volumes from the MIRD phantom. Although this study considered F-18-FDG, combined use of whole-body PET and MRI might be quite effective for improving the accuracy of estimations of the cumulated activity and absorbed dose of positron-labelled radiopharmaceuticals.

︎全件表示 ︎最初の5件までを表示

MISC 65

  1. プラナー像定量のためのconjugate法における減弱・散乱線補正が定量精度に及ぼす影響の基礎検討

    佐々木里奈, 筒井亮佑, 小田桐逸人, KIM KyeongMin, 渡部浩司, 志田原美保

    核医学技術 40 2020年

    ISSN:0289-100X

  2. I-123 BMIPP経口投与による胸管シンチグラフィの基礎的検討

    高浪 健太郎, 小田桐 逸人, 志田原 美保, 高瀬 圭

    核医学 55 (Suppl.) S172-S172 2018年11月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  3. ラットPETを用いたヒト内部被曝線量の非侵襲的推定手法の検討

    志田原 美保, 猪又 嵩斗, 小山 千莉, 船木 善仁, 田代 学, 古本 祥三, 谷内 一彦, 権田 幸祐, 渡部 浩司

    核医学 54 (Suppl.) S199-S199 2017年9月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

  4. NEMA NU4-2008に基づいた小動物用PET装置ClairvivoPETの性能評価

    志田原 美保, Nai Ying Hway, 四月朔日 聖一, 石川 洋一, 田代 学, 古本 祥三, 谷内 一彦, 権田 幸祐, 渡部 浩司

    核医学 53 (Suppl.) S312-S312 2016年10月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  5. Biomathematical modeling approach to predict clinical SUVR in amyloid PET imaging towards efficient radioligand discovery and development

    Y. Arakawa, M. Shidahara, Y. Nai, S. Furumoto, C. Seki, N. Okamura, M. Tashiro, M. Tashiro, Y. Kudo, K. Yanai, K. Gonda, H. Watabe

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 42 S70-S70 2015年10月

    出版者・発行元:SPRINGER

    ISSN:1619-7070

    eISSN:1619-7089

  6. 生体数学モデルを用いたアミロイドPETイメージングにおける臨床SUVR予測

    荒川 悠真, 志田原 美保, Nai Ying Hwey, 古本 祥三, 関 千江, 岡村 信行, 田代 学, 工藤 幸司, 谷内 一彦, 権田 幸祐, 渡部 浩司

    核医学 52 (3) 260-260 2015年9月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  7. Noise Power Spectrum in PROPELLER MR Imaging 査読有り

    Magn Reson Med Sci 14 (3) 235-242 2015年

    DOI: 10.2463/mrms.2014-0071  

  8. Measurement of Free Fraction in Plasma for Biomathematical Prediction of SUVR of Amyloid PET Radiotracers

    Nai Y.-H., Shidahara M., Seki C., Watanuki S., Funaki Y., Ishikawa Y., Furumoto S., Watabe H.

    CYRIC annual report 2014 73-77 2015年

    出版者・発行元:Cyclotron and Radioisotope Center, Tohoku University

  9. タウイメージング薬剤[18F]THK-5117を用いたPET臨床試験(速報)

    田代 学, 岡村 信行, 古本 祥三, 四月朔日 聖一, 平岡 宏太良, 古川 勝敏, 志田原 美保, 石木 愛子, 冨田 尚希, 松田 林, 稲見 暁惠, 武田 和子, 三宅 正泰, 船木 善仁, 岩田 錬, 工藤 幸司, 荒井 啓行, 谷内 一彦

    核医学 51 (1) 28-28 2014年2月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  10. アミロイドイメージング用PET薬剤[18F]FACTの内部被ばく線量評価

    志田原 美保, 田代 学, 岡村 信行, 古本 祥三, 古川 勝敏, 四月朔日 聖一, 平岡 宏太良, 三宅 正泰, 岩田 錬, 田村 元, 荒井 啓行, 工藤 幸司, 谷内 一彦

    核医学 50 (2) 70-70 2013年5月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  11. フッ素標識アミロイドイメージング薬剤[18F]FACTの動態解析

    田代 学, 岡村 信行, 古本 祥三, 四月朔日 聖一, 平岡 宏太良, 古川 勝敏, 志田原 美保, 三宅 正泰, 船木 善仁, 岩田 錬, 工藤 幸司, 荒井 啓行, 谷内 一彦

    核医学 50 (2) 70-70 2013年5月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  12. Investigation of Renal Medullary Blood Flow Imaging in Human

    Ohsaki Y., Mori T., Koizumi K., Shidahara M., Yagi A., Tashiro M., Iwata R., Oba I., Furushou M., Makiko C., Tanno M., Hiraoka K., Watanuki S., Ishikawa Y., Miyake M., Ito S.

    CYRIC annual report 2012 146-148 2013年

    出版者・発行元:Cyclotron and Radioisotope Center, Tohoku University

  13. Radiation Dosimetry of the F-18 Labelled Amyloid Imaging Probe [18F]FACT in Humans

    Shidahara M., Tashiro M., Okamura N., Furumoto S., Furukawa K., Watanuki S., Hiraoka K., Miyake M., Watabe H., Iwata R., Arai H., Kudo Y., Gonda K., Tamura H., Yanai K.

    CYRIC annual report 2012 137-143 2013年

    出版者・発行元:Cyclotron and Radioisotope Center, Tohoku University

  14. Biodistribution and radiation dosimetry of F-18 labeled amyloid imaging probe [18F]FACT in humans

    M. Shidahara, M. Tashiro, N. Okamura, S. Furumoto, K. Furukawa, S. Watanuki, K. Hiraoka, M. Miyake, R. Iwata, H. Tamura, H. Arai, Y. Kudo, K. Yanai

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 39 S407-S408 2012年10月

    出版者・発行元:SPRINGER

    ISSN:1619-7070

  15. Preliminary investigation of biomathematical modeling approach to predict clinical usefulness of PET amyloid imaging probes

    M. Ito, M. Shidahara, S. Furumoto, C. Seki, N. Okamura, M. Tashiro, K. Yanai, Y. Kudo, H. Tamura

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 39 S388-S388 2012年10月

    出版者・発行元:SPRINGER

    ISSN:1619-7070

  16. Wavelet-based resolution recovery using an anatomical prior provides quantitative recovery for human population phantom PET [C-11]raclopride data

    Miho Shidahara, Charalampos Tsoumpas, Colm McGinnity, Takashi Kato, Hajime Tamura, Alexander Hammers, Hiroshi Watabe, Federico Turkheimer

    JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM 32 S138-S139 2012年8月

    出版者・発行元:NATURE PUBLISHING GROUP

    ISSN:0271-678X

  17. アミロイドイメージング用PET薬剤[18F]FACTの体内分布および内部被曝線量評価

    志田原 美保, 田代 学, 岡村 信行, 古本 祥三, 古川 勝敏, 四月朔日 聖一, 田村 元, 岩田 錬, 荒井 啓行, 工藤 幸司, 谷内 一彦

    核医学 49 (3) S239-S239 2012年8月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  18. アミロイドイメージングを用いたアルツハイマー病発症リスク予測法の実用化に関する多施設臨床研究[<sup>18</sup>F]FACTを用いたアルツハイマー病診断における定量法の検討

    田代学, 志田原美保, 志田原美保, 岡村信行, 古川勝敏, 古本祥三, 古本祥三, 平岡宏太良, 船木善仁, 四月朔日聖一, 三宅正泰, 冨田尚希, 石川洋一, 岩田錬, 田村元, 工藤幸司, 荒井啓行, 谷内一彦, 谷内一彦

    アミロイドイメージングを用いたアルツハイマー病発症リスク予測法の実用化に関する多施設臨床研究 平成23年度 総括・分担研究報告書 2012年

  19. PET脳神経受容体画像化における最尤推定を用いたグラフィカル解析法の改良

    志田原美保, 関千江, 長縄美香, 坂田宗之, 石川雅智, 伊藤浩, 菅野巌, 石渡喜一, 木村裕一

    東北医学雑誌 123 (1) 2011年

    ISSN:0040-8700

  20. 陽電子断層撮影装置(PET)を用いた脳神経受容体機能の定量解析 (東北大医学部保健学科紀要)

    志田原美保, 田村元

    東北大医学部保健学科紀要 20 (1) 1-16 2011年1月

    出版者・発行元:東北大学医学部保健学科

    ISSN:1348-8899

  21. [11C]MNPAを用いたドーパミンD2受容体占有率測定における誤差解析

    志田原 美保, 伊藤 浩, 大塚 達以, 生駒 洋子, 荒川 亮介, 小高 文聰, 関 千江, 高野 晴成, 高橋 英彦, 田村 元, 須原 哲也

    核医学 47 (3) 369-369 2010年9月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  22. Correction of [11C]diprenorphine PET data for the partial-volume effect: Quantification of opioid receptor binding following spontaneous epileptic seizures

    C. J. McGinnity, M. Shidahara, S. Keihaninejad, D. A. Riano Barros, I. S. Gousias, R. A. Heckemann, D. J. Brooks, M. J. Koepp, F. E. Turkheimer, A. Hammers

    NEUROIMAGE 52 S209-S209 2010年8月

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.neuroimage.2010.04.171  

    ISSN:1053-8119

  23. A noise reduction method for graphical analyses with KL-expansion during transient equilibrium condition

    K. Sakaguchi, M. Naganawa, M. Sakata, M. Shidahara, C. Seki, K. Ishiwata, Y. Kimura

    JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM 29 S333-S333 2009年10月

    出版者・発行元:NATURE PUBLISHING GROUP

    ISSN:0271-678X

  24. Error analysis of dopamine D-2 receptor occupancy study with agonist ligand [C-11]MNPA

    M. Shidahara, H. Ito, T. Otsuka, Y. Ikoma, C. Seki, F. Kodaka, R. Arakawa, H. Takano, H. Takahashi, Y. Kimura, I. Kanno, T. Suhara

    JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM 29 S347-S347 2009年10月

    出版者・発行元:NATURE PUBLISHING GROUP

    ISSN:0271-678X

  25. アミロイド前駆体蛋白遺伝子導入マウスにおける11C-PIB脳内結合の定量

    関 千江, 徳永 正希, 服部 聡子, 志田原 美保, 中尾 隆士, 岡内 隆, 前田 純, 樋口 真人, 木村 裕一, 須原 哲也

    核医学 46 (3) 262-262 2009年9月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  26. 抗精神病薬投与時のドーパミンD2レセプター占有率の脳内局所差に関する研究

    伊藤 浩, 須原 哲也, 高橋 英彦, 高野 晴成, 荒川 亮介, 奥村 正紀, 大塚 達以, 小高 文聰, 志田原 美保

    精神薬療研究年報 (41) 17-18 2009年3月

    出版者・発行元:(公財)先進医薬研究振興財団

    ISSN:1346-1702

  27. Logan法における主成分分析を用いた雑音低減処理の評価

    坂口和也, 長縄美香, 坂田宗之, 志田原美保, 関千江, 石渡喜一, 木村裕一

    核医学 46 (3) 2009年

    ISSN:0022-7854

  28. 連検定を用いた Logan graphical analysis の開始点決定によるPET神経受容体定量化の精度改善

    大柿 宏人, 木村 裕一, 長縄 美香, 坂田 宗之, 志田原 美保, 菅 幹生

    電子情報通信学会技術研究報告. MI, 医用画像 108 (209) 27-31 2008年9月10日

    出版者・発行元:一般社団法人電子情報通信学会

    ISSN:0913-5685

    詳細を見る 詳細を閉じる

    Logan Graphical Analysis (LGA)は、陽電子断層像を用いた神経受容体の画像化において標準的に使用されるアルゴリズムである。LGAは、血中及び組織中の放射能濃度の経時変化の間で成立する直線関係を用いるため、その成立時刻(t^*)を指定しなければならないが、雑音を多く含むPETデータにおいて全画素に対するt^*の推定は容易ではない。そこで本手法では、適切なt^*の下では、直線推定による残差の符号がランダムになることに着目し、ランダム性をノンパラメトリックに判定する連検定を用いてt^*を画素毎に決定するアルゴリズムを提案した。その結果、提案手法による神経受容体の推定精度改善が示唆された。

  29. 新しいグラフプロット法による脳神経受容体結合能の定量解析

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

    核医学 45 (3) S227-S227 2008年9月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  30. 異なるPET装置でのドーパミンD2受容体結合能の比較

    小高 文聰, 伊藤 浩, 高橋 英彦, 高野 晴成, 荒川 亮介, 奥村 正紀, 大塚 達以, 三好 美智恵, 関根 瑞穂, 志田原 美保, 須原 哲也

    核医学 45 (3) S237-S237 2008年9月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  31. 抗精神病薬投与時ドーパミンD2レセプター占有率の脳内局所差の検討

    伊藤 浩, 荒川 亮介, 高橋 英彦, 高野 晴成, 奥村 正紀, 大塚 達以, 小高 文聰, 志田原 美保, 須原 哲也

    核医学 45 (3) S229-S229 2008年9月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

    eISSN:2189-9932

  32. Regional differences in occupancy of dopamine D-2 receptors by second-generation antipsychotics in humans measured using PET

    Hiroshi Ito, R. Arakawa, H. Takahashi, H. Takano, M. Okumura, T. Otsuka, Y. Ikoma, M. Shidahara, T. Suhara

    NEUROIMAGE 41 T188-T188 2008年

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.neuroimage.2008.04.155  

    ISSN:1053-8119

  33. Quantification of C-11-PIB kinetics in mouse brain using metabolite-corrected arterial input function

    Chie Seki, M. Tokunaga, S. Haffori, M. Shidahara, R. Nakao, J. Maeda, H. Toyama, T. Irie, M. Higuchi, T. Suhara, I. Kanno, Y. Kimura

    NEUROIMAGE 41 T32-T32 2008年

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.neuroimage.2008.04.206  

    ISSN:1053-8119

  34. PET脳神経受容体画像化におけるMAP推定を用いたグラフィカル解析法の提案

    志田原美保, 関千江, 長縄美香, 坂田宗之, 石川雅智, 菅野巖, 石渡喜一, 木村裕一

    日本生体医工学会大会プログラム・論文集(CD-ROM) 47th 2008年

  35. PET脳神経受容体画像化におけるMAP推定を用いたグラフィカル解析法の提案

    志田原美保, 関千江, 長縄美香, 坂田宗之, 石川雅智, 菅野巌, 石渡喜一, 木村裕一

    核医学 45 (3) 2008年

    ISSN:0022-7854

  36. 連検定によるLogan法における開始時刻の決定

    木村裕一, 大柿宏人, 大柿宏人, 長縄美香, 志田原美保, 坂田宗之, 石渡喜一, 菅幹生

    核医学 45 (3) 2008年

    ISSN:0022-7854

  37. Reduction of noise-induced underestimation in Logan graphical analysis using scale invariant linear estimation

    Muneyuki Sakata, Y. Kimura, M. Naganawa, M. Shidahara, C. Seki, K. Oda, K. Ishii, K. Ishiwata

    NEUROIMAGE 41 T82-T82 2008年

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.neuroimage.2008.04.051  

    ISSN:1053-8119

  38. Parametric Imaging of the total volume of distrihution using MAP estimation for logan graphical analysis

    Miho Shidahara, Y. Kimura, C. Seki, M. Naganawa, M. Sakata, M. Ishikawa, H. Ito, T. Suhara, K. Ishiwata, I. Kanno

    NEUROIMAGE 41 T83-T83 2008年

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.neuroimage.2008.04.052  

    ISSN:1053-8119

  39. A new graphic plot method for determination of neuroreceptor binding in PET studies

    Hiroshi Ito, T. Yokoi, Y. Ikoma, M. Shidahara, C. Seki, H. Takahashi, H. Takano, Y. Kimura, T. Suhara

    NEUROIMAGE 41 T67-T67 2008年

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.neuroimage.2008.04.037  

    ISSN:1053-8119

  40. PET kinetic analysis: error consideration of quantitative analysis in dynamic studies

    Yoko Ikoma, Hiroshi Watabe, Miho Shidahara, Mika Naganawa, Yuichi Kimura

    ANNALS OF NUCLEAR MEDICINE 22 (1) 1-11 2008年1月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s12149-007-0083-2  

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    Positron emission tomography dynamic studies have been performed to quantify several biomedical functions. In a quantitative analysis of these studies, kinetic parameters were estimated by mathematical methods, such as a nonlinear least-squares algorithm with compartmental model and graphical analysis. In this estimation, the uncertainty in the estimated kinetic parameters depends on the signal-to-noise ratio and quantitative analysis method. This review describes the reliability of parameter estimates for various analysis methods in reversible and irreversible models.

  41. microPET Focus220を用いたサルPET検査における吸収補正に関する検討

    志田原美保, 寅松千枝, 岡内隆, 関千江, 長縄美香, 永井裕司, 伊藤浩, 大林茂, 木村裕一, 菅野巖

    核医学 44 (3) 315 2007年10月30日

    ISSN:0022-7854

  42. The effect of activity outside the field of view in estimation of human neuroreceptor binding with PET.

    T. Shiraishi, M. Shidahara, K. Tanimoto, A. Ando, T. Miyamoto, R. Koganezawa, H. Fukuda, K. Watanabe

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 34 S403-S403 2007年10月

    出版者・発行元:SPRINGER

    ISSN:1619-7070

  43. 11C-Verapamil P糖タンパク機能画像化に対するクラスタリング動態法の適用

    木村 裕一, 長縄 美香, 志田原 美保, 関 千江, 織田 圭一, 石井 賢二, 石渡 喜一

    核医学 44 (3) 314-314 2007年10月

    出版者・発行元:(一社)日本核医学会

    ISSN:0022-7854

  44. PET kinetic analysis: wavelet denoising of dynamic PET data with application to parametric imaging

    Miho Shidahara, Yoko Ikoma, Jeff Kershaw, Yuichi Kimura, Mika Naganawa, Hiroshi Watabe

    ANNALS OF NUCLEAR MEDICINE 21 (7) 379-386 2007年9月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s12149-007-0044-9  

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    Physiological functions (e.g., cerebral blood flow, glucose metabolism, and neuroreceptor binding) can be investigated as parameters estimated by kinetic modeling using dynamic positron emission tomography (PET) images. Imaging of these physiological parameters, called parametric imaging, can locate the regional distribution of functionalities. However, the most serious technical issue affecting parametric imaging is noise in dynamic PET data. This review describes wavelet denoising of dynamic PET images for improving image quality in estimated parametric images. Wavelet denoising provides significantly improved quality directly to dynamic PET images and indirectly to estimated parametric images. The application of wavelet denoising to radio-ligand and kinetic analysis is still in the development stage, but even so, it is thought that wavelet techniques will have a substantial impact on nuclear medicine in the near future.

  45. Development of a digital phantom for evaluation of fundamental performance on SPECT 査読有り

    Nobutoku Motomura, Koichi Ogawa, Miho Shidahara, Hideo Onishi

    2007 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-11 6 4524-+ 2007年

    出版者・発行元:IEEE

    ISSN:1082-3654

    詳細を見る 詳細を閉じる

    We have developed digital phantoms to be used for a basic education on an image quality and a quantification of SPECT data. Differing from the digital phantoms developed by Castiglioni and et al, several SPECT projection data sets were generated by Monte Carlo simulations (EGS4 code) with different acquisition parameters. A physical, brain and cardiac phantoms were generated. An external shape of the physical phantom is a 200 mm diameter and 200 rum long cylinder. Three objects, each of which consists of 4 mm, 10 mm, 20 rum, 40 mm and 60 mm diameter rods (each rod is 30 mm long), are set in. Shapes of the brain phantom were created using a MRI data set. Shapes of the cardiac phantom were created using a CT image set. Tc-99m was used for the simulations. The Monte Carlo simulations were performed, taking account of Compton scattering, photoelectric effect and degradation of a spatial resolution due to collimator aperture. SPECT acquisition parameters were collimator type, pixel length, acquired photon count, projection number and radius of detector rotation. Ideal SPECT projection data and transaxial image were generated as reference (standard) data. Several attenuation maps with different attenuation coefficients can be used for an evaluation of an attenuation correction. The triple energy window setting was used for an evaluation of a scatter correction such as the TEW method. Overall, primary and scattered photons were saved in different files. By using the proposed phantoms, spatial resolution, contrast, signal to noise ratio and quantification with SPECT data acquisition and processing parameters were evaluated. The phantoms are considered to be useful for understanding the fundamental performance on SPECT.

  46. PET kinetic analysis - Pitfalls and a solution for the Logan plot

    Yuichi Kimura, Mika Naganawa, Miho Shidahara, Yoko Ikoma, Hiroshi Watabe

    ANNALS OF NUCLEAR MEDICINE 21 (1) 1-8 2007年1月

    出版者・発行元:SPRINGER

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    The Logan plot is a widely used algorithm for the quantitative analysis of neuroreceptors using PET because it is easy to use and simple to implement. The Logan plot is also suitable for receptor imaging because its algorithm is fast. However, use of the Logan plot, and interpretation of the formed receptor images should be regarded with caution, because noise in PET data causes bias in the Logan plot estimates. In this paper, we describe the basic concept of the Logan plot in detail and introduce three algorithms for the Logan plot. By comparing these algorithms, we demonstrate the pitfalls of the Logan plot and discuss the solution.

  47. PET kinetic analysis - compartmental model

    Hiroshi Watabe, Yoko Ikoma, Yuichi Kimura, Mika Naganawa, Miho Shidahara

    ANNALS OF NUCLEAR MEDICINE 20 (9) 583-588 2006年11月

    出版者・発行元:JAPANESE SOCIETY NUCLEAR MEDICINE

    DOI: 10.1007/BF02984655  

    ISSN:0914-7187

    詳細を見る 詳細を閉じる

    PET enables not only visualization of the distribution of radiotracer, but also has ability to quantify several biomedical functions. Compartmental model is a basic idea to analyze dynamic PET data. This review describes the principle of the compartmental model and categorizes the techniques and approaches for the compartmental model according to various aspects: model design, experimental design, invasiveness, and mathematical solution. We also discussed advanced applications of the compartmental analysis with PET.

  48. PETによる脳内神経受容体の定量化

    生駒 洋子, 志田原 美保, 関 千江, 伊藤 浩, 高橋 英彦, 須原 哲也, 菅野 巌

    電気学会研究会資料. MBE, 医用・生体工学研究会 2006 (31) 17-20 2006年7月14日

  49. 脳血流SPECT画像を用いたアルツハイマー病患者と正常者の弁別読影精度を数値解析で予測する試み (核医学)

    志田原美保, 井上健太郎, 瀧靖之, 岡田賢, 後藤了以, 木之村重男, 福田寛, 丸山将浩, 荒井啓行

    核医学 42 (3) 313-313 2005年9月

  50. Impact of image-based scatter correction for (IMP)-I-123-SPECT and SPM analysis

    M Shidahara, H Watabe, KM Kim, T Kato, S Kawatsu, R Kato, K Yoshimura, H Iida, K Ito

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 31 S402-S402 2004年8月

    出版者・発行元:SPRINGER

    ISSN:1619-7070

  51. Usefulness of FDG-PET and AD-tsum method in diagnostic imaging of Alzheimer's disease

    T Kato, K Ito, K Herholz, G Zuendorf, Y Abe, Y Washimi, Y Arahata, K Hatano, S Kawatsu, A Nagano-Saito, M Shidahara, K Iwai, T Yamada, T Kachi

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 31 S363-S363 2004年8月

    出版者・発行元:SPRINGER

    ISSN:1619-7070

  52. Impact of image-based scatter correction for IMP-SPECT and SPM analysis.

    M Shidahara, H Watabe, K Kim, T Kato, S Kawatsu, R Kato, K Hatano, H Iida, K Ito

    JOURNAL OF NUCLEAR MEDICINE 44 (5) 263P-263P 2003年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  53. Development and application of a GSO detector assembly for a continuous blood sampling system.

    N Kudomi, E Choi, H Watabe, KM Kim, M Shidahara, M Ogawa, N Teramoto, E Sakamoto, S Yamamoto, H Iida

    JOURNAL OF NUCLEAR MEDICINE 43 (5) 229P-229P 2002年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  54. Utilization of dynamic sinogram using ECAT EXACT and 15O-labeled compounds for accurate rCBF, rOEF and rCMRO2.

    M Shidahara, H Watabe, K Hayashida, K Kim, T Nakamura, T Kato, K Ito, H Iida

    JOURNAL OF NUCLEAR MEDICINE 43 (5) 207P-208P 2002年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  55. Optimal scan time of O-15-labeled gas inhalation method for measurement of cerebral oxygen extraction fraction.

    M Shidahara, H Watabe, K Kim, T Nakamura, T Kato, K Ito, H Iida

    JOURNAL OF NUCLEAR MEDICINE 43 (5) 211P-211P 2002年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  56. Noise property of two CMRO2 quantitation methods with a short bolus inhalation of O-15(2).

    N Kudomi, H Watabe, Y Miyake, KM Kim, M Shidahara, K Hayashida, N Oka, M Sagou, Y Ishida, T Hayahsi, H Iida

    JOURNAL OF NUCLEAR MEDICINE 43 (5) 211P-211P 2002年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  57. Contribution of scatter correction in the kinetic analysis of a D2 receptor ligand with SPECT.

    KM Kim, H Watabe, M Shidahara, Y Onishi, Y Yonekura, H Iida

    JOURNAL OF NUCLEAR MEDICINE 42 (5) 217P-217P 2001年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  58. Effect of scatter correction on quantitative estimation in receptor ligand study with SPECT.

    KM Kim, H Watabe, M Shidahara, A Varrone, M Fujita, RB Innis, H Iida

    JOURNAL OF NUCLEAR MEDICINE 42 (5) 184P-184P 2001年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  59. Validation of shortening scan intervals in repeat measurement of cerebral blood flow with O-15 water and PET.

    H Watabe, Y Kondoh, KM Kim, M Shidahara, H Iida

    JOURNAL OF NUCLEAR MEDICINE 42 (5) 220P-220P 2001年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  60. Optimization and validation for quantitative brain perfusion imaging using Tc-99m ethyle cycteinate dimmer (ECD) and SPECT.

    H Iida, M Shidahara, H Watabe, K Kitamura, KM Kim, T Hachiya

    JOURNAL OF NUCLEAR MEDICINE 41 (5) 185P-185P 2000年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  61. Correction for the coincidence detections due to Compton scattering on 3-dimensional acquisition PET for the quantitative thorax measurement.

    Y Narita, M Shidahara, T Nakamura, T Fujiwara, S Watanuki, M Miyake, M Itoh

    JOURNAL OF NUCLEAR MEDICINE 39 (5) 98P-98P 1998年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  62. Internal dosimetry by TLD method and comparison with the result of whole body PET

    HM Deloar, T Fujiwara, M Shidahara, T Nakamura, H Watabe, A Yamadera, M Itoh

    JOURNAL OF NUCLEAR MEDICINE 39 (5) 187P-188P 1998年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  63. Radiation absorbed dose estimates for 2-[F-18]fluoro-2-deoxy-D-glucose by using whole body PET and MRI

    HM Deloar, M Shidahara, T Fujiwara, T Nakamura, M Miyake, S Watanuki, M Itoh

    JOURNAL OF NUCLEAR MEDICINE 38 (5) 957-957 1997年5月

    出版者・発行元:SOC NUCLEAR MEDICINE INC

    ISSN:0161-5505

  64. Compton Scattering Correction in 3D-PET Study Based on the Unfolding Method

    Shidahara M., Nakamura T., Narita Y., Miyake M., Watanuki S., Fujiwara T., Itoh M.

    CYRIC annual report 1997 117-122 1997年

    出版者・発行元:Cyclotron and Radioisotope Center, Tohoku University

    詳細を見る 詳細を閉じる

    開始ページ、終了ページ: 冊子体のページ付け

  65. Radiation Absorbed Dose Estimation of 2-[F-18]Fluoro-2-Deoxy-D-Glucose Using Whole Body PET and Measured Organ Volume MRI

    Deloar H. M., Shidahara M., Fujiwara T., Nakamura T., Miyake M., Watanuki S., Watabe H., Narita M., Itoh M.

    CYRIC annual report 1996 135-140 1996年

    出版者・発行元:Cyclotron and Radioisotope Center, Tohoku University

    詳細を見る 詳細を閉じる

    開始ページ、終了ページ: 冊子体のページ付け

︎全件表示 ︎最初の5件までを表示

書籍等出版物 5

  1. 核医学検査技術学(改訂4版) (放射線技術学シリーズ)

    大西, 英雄, 本村, 信篤, 松友, 紀和, 日本放射線技術学会

    オーム社 2022年3月15日

    ISBN: 4274228266

  2. 図解診療放射線技術実践ガイド : 第一線で必ず役立つ知識・実践のすべて

    遠藤, 啓吾, 杜下, 淳次, 小倉, 明夫, 片渕, 哲朗, 赤澤, 博之, 西谷, 源展

    文光堂 2020年1月

    ISBN: 9784830642326

  3. 放射線技術学シリーズ 核医学検査技術学 改訂3版

    大西英雄, 市原 隆, 山本智朗, 日本放射線技術学会

    オーム社 2016年5月21日

    ISBN: 4274218600

  4. Neural Metabolism In Vivo, Advances in Neurobiology, Vol. 4

    Choi In-Young, Gruetter Rolf, eds, Habib Zaidi, Miho Shidahara

    Springer 2012年1月25日

  5. Encyclopedia of Computational Neuroscience

    Shidahara M, Watabe H, Kanno I

    Springer

講演・口頭発表等 62

  1. Prediction of time-activity curves by machine learning and biomathematical model for discovery and development of CNS PET ligands

    Kyosei Sahashi, Itsuki Miyajima, Ayano Yoshikawa, Miho Shidahara

    The13th Congress of the World Federation of Nuclear Medicine and Biology

  2. Novel database of kinetic parameters in human brain for existing CNS-PET tracers

    Itsuki Miyajima, Ayano Yoshikawa, Kyosei Sahashi, Miho Shidahara

    The13th Congress of the World Federation of Nuclear Medicine and Biology

  3. Development of the methodology to predict clinical PET images for efficient CNS PET radioligand development using serotonin targeting ligands

    Ayano Yoshikawa, Itsuki Miyajima, Kyosei Sahashi, Kotaro Hiraoka, Miho Shidahara

    The13th Congress of the World Federation of Nuclear Medicine and Biology

  4. Preliminary investigation of point source tracking algorithm in planar imaging system for motion correction of moving subjects

    Moe Nishikawa, Ayano Yoshikawa, Hiroshi Watabe, Miho Shidahara

    The13th Congress of the World Federation of Nuclear Medicine and Biology

  5. 理工系から考える日本核医学会のダイバーシティ推進

    志田原美保

    第62回日本核医学会学術総会 2022年9月10日

  6. Merging Biomathematical modelling and Machine learning to predict time-activity curves for PET CNS radioligand development

    Miho Shidahara, Chie Seki, Hiroshi Watabe

    2021 VIRTUAL IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE 2021年10月23日

  7. PET創薬のための臨床画像予測技術の開発 -アミロイドPETにおける基礎検討-

    志田原美保, 阿部祥樹

    第59回日本核医学会学術総会 2019年11月3日

  8. PET創薬のための数理モデル構築の試み 招待有り

    志田原美保

    PETサマーセミナ2019 in 福島 2019年8月24日

  9. Prediction of rat brain PET image with [11C]raclopride data based on biomathematical modelling approach

    Miho Shidahara, Sotaro Momosaki, Hiroshi Watabe, Nozomi Takai, Takemi Rokukawa, Koji Abe

    Brain & Brain PET 2019 2019年7月6日

  10. Error propagation property of 5 partial volume correction algorithms for [18F]THK5351 PET imaging

    Senri Oyama, Miho Shidahara, Benjamin A. Thomas, KEisuke Matsubara, Masanobu Ibaraki, Shoichi Watanuki, Hiroshi Watabe, Manabu Tashiro

    Annual Congress of the European Association of Nuclear Medicine (EANM 2018)

  11. 脳を対象とした放射性薬剤の動態解析~基礎から最新の話題まで~ 招待有り

    志田原美保

    日本核医学技術学会第24回東北地方会 2018年9月1日

  12. PET臨床データ定量解析

    志田原 美保

    第6回画像診断セミナー 2012年2月7日

  13. 『[18F]FACTの体内分布及び内部被曝線量評価

    志田原 美保

    第1回核医学画像解析研究会 2011年11月14日

  14. 小動物用ピンホールSPECT装置の回転半径と体軸方向の有効視野の関係に関する検討

    志田原 美保, 犬伏 正幸, 田村 元, 渡部 浩司, 村井 知佳, 小泉 満, 佐賀 恒夫

    第51回日本核医学会学術総会 2011年10月28日

  15. Wavelet-based resolution recovery using anatomical prior provides quantitative recovery for human population phantom PET [11C]raclopride data 国際会議

    Shidahara M, Tsoumpas C, McGinnity CJ, Kato T, Tamura H, Hammers A, Watabe H, Turkheimer FE

    IEEE Nuclear Science Symposium and Medical Imaging Conference 2011年10月23日

  16. 縦緩和率・フリップ角空間分解能同時測定の一方法

    田村 元, 大田 英輝, 永坂 竜男, 伊藤 謙吾, 志田原 美保, 諏訪 亨, 小森 芳秋, 小原 真

    第39回日本磁気共鳴医学会大会 2011年9月29日

  17. Quantitation of Changes in Cerebral Blood Flow and Longitudinal Relaxation Rate (R1=1/T1) Induced by Mild Hyperoxia 国際会議

    Tamura H, Nagasaka T, Shimada K, Nishikata J, Shidahara M, Mugikura S, Machida Y

    Annual meeting of International Society of Magnetic Resonance in Medicine, Montreal 2011年5月5日

  18. PET臨床データ定量解析

    志田原美保

    第5回画像診断セミナー 2011年2月21日

  19. [11C]MNPAを用いたドーパミンD2受容体 占有率測定における誤差解析

    志田原 美保, 伊藤 浩, 大塚 達以, 生駒 洋子, 荒川 亮介, 小高 文聰, 関 千江, 高野 晴成, 高橋 英彦, 木村 裕一, 田村 元, 菅野 巖, 須原 哲也

    第50回日本核医学会学術総会 2010年11月11日

  20. 核医学画像における医師の読影成績を 数値解析で予測する試み

    志田原美保

    第38回日本放射線技術学会秋季学術大会第61回核医学分科会 2010年10月16日

  21. 吸入酸素によるMRI信号変化の基礎研究:ヒト脳における血流量の変化

    西片 純基, 志田原 美保, 田頭 豊, 栗田 準一郎, 永坂 竜夫, 田村 元

    第38回日本放射線技術学会秋季学術大会 2010年10月14日

  22. 脳組織の酸素濃度とMRI縦緩和時間

    田村 元, 永坂 竜夫, 島田 一生, 西片 純基, 志田原 美保

    第14回酸素ダイナミクス研究会 2010年9月4日

  23. Quantitative evaluation of 11C-PIB binding in amyloid precursor protein transgenic mouse brains 国際会議

    Seki C, Higuchi M, Tokunaga M, Hattori S, Maruyama M, Shidahara M, Okauchi T, Nakao R, Maeda J, Kimura Y, Kanno I, Suhara T

    Functional Neuroreceptor Mapping of the Living Brain (NRM2010) 2010年7月22日

  24. Correction Of [11C]Diprenorphine PET Data For The Partial-Volume Effect: Application to Quantification Of Opioid Receptor Binding Following Spontaneous Epileptic Seizures 国際会議

    McGinnity CJ, Shidahara M, Keihaninejad S, Riano Barros DA, Gousias IS, Heckemann RA, Koepp MJ, Turkheimer FE, Hammers A

    Functional Neuroreceptor Mapping of the Living Brain (NRM2010) 2010年7月22日

  25. Quantifiaction of opioid receptor availability following spontaneous epilepticseizures 国際会議

    McGinnity CJ, Shidahara M, Keihaninejad S, Riano Barros DA, Gousias IS, Heckemann RA, Koepp MJ, Turkheimer FE, Hammers A

    9th EUROPEAN CONGRESS ON EPILEPTOLOGY 2010年6月27日

  26. 画像処理技術(2)

    志田原美保

    第3回 核医学専門技師研修セミナー 2010年5月23日

  27. 脳神経受容体測定の施設間較差について―レビュー―

    志田原美保

    脳PETワークショップ 2010年4月9日

  28. PET臨床データ定量解析

    志田原美保

    第4回画像診断セミナー 2010年2月23日

  29. Functional and structural synergy for resolution recovery and partial volume correction in Brain PET 国際会議

    Shidahara Miho

    UK-Japan workshop "Multimodal Methods for Monitoring Function in the Brain 2010年1月26日

  30. 脳PET画像の部分容積効果補正を目的とした 形態画像の活用

    志田原 美保, Charalampos Tsoumpas, Alexander Hammers, Nicolas Boussion, Dimitris Visvikis, 伊藤 浩, 木村 裕一, 須原 哲也, 菅野 巖, Federico Turkheimer

    志田原美保, Charalampos Tsoumpas, Alexander Hammers,Nicolas Boussion, Dimitris Visvikis, 伊藤浩, 木村裕一, 須原哲也,菅野巖, Federico Turkheimer 2009年10月1日

  31. 単孔または5孔のピンホールコリメータを装着した小動物用SPECTシステムの実用性能評価

    犬伏 正幸, 志田原 美保, 村井 知佳, 関 千江, 辻 厚至, 小泉 満, 菅野 巌, 佐賀 恒夫

    第49回日本核医学会総会 2009年10月1日

  32. ヒトNa+/I-共輸送タンパク(hNIS)遺伝子安定発現大腸癌細胞株マウス担癌モデルのレポーター遺伝子イメージング

    村井 知佳, 犬伏 正幸, 志田原 美保, 辻 厚至, 小泉 満, 北川 善政, 佐賀 恒夫

    第49回日本核医学会総会 2009年10月1日

  33. Functional and structural synergy for resolution recovery and partial volume correction in Brain PET 国際会議

    Shidahara Miho

    UK PET SIG Meeting 2008年12月4日

  34. PET脳神経受容体画像化におけるMAP推定を用いたグラフィカル解析法の提案

    志田原 美保, 関 千江, 長縄 美香, 坂田 宗之, 菅野 巖, 石渡 喜一, 木村 裕一

    第47回日本生体医工学会大会 2008年5月8日

  35. PET臨床データ定量解

    志田原 美保

    PETデータ解析ゼミ 2008年3月19日

  36. ,『(21)PET動態解析画像の画質改善について

    志田原美保

    次世代PET研究会 2008年1月21日

  37. サル脳FDG-PET動態解析における動脈採血省略法EPICA

    長縄 美香, 塚田 秀夫, 大庭 弘行, 石渡 喜一, 関 千江, 志田原 美保, 木村 裕一

    第47回日本核医学会総会 2007年11月4日

  38. 11C-Verapamil P糖タンパク機能画像化に対するクラスタリング動態法の適用

    木村 裕一, 長縄 美香, 志田原 美保, 関 千江, 織田 圭一, 石井 賢二, 石渡 喜一

    第47回日本核医学会総会 2007年11月4日

  39. microPET Focus220を用いたサルPET検査における吸収補正に関する検討

    志田原 美保, 寅松 千枝, 岡内 隆, 関 千江, 長縄 美香, 永井 裕司, 伊藤 浩, 大林 茂, 木村 裕一, 菅野 巖

    第47回日本核医学会総会 2007年11月4日

  40. 小動物PET定量解析における採血量を考慮した採血タイミングの検討

    関 千江, 徳永 正希, 岡内 隆, 志田原 美保, 長縄 美香, 伊藤 浩, 樋口 真人, 木村 裕一

    第47回日本核医学会総会 2007年11月4日

  41. PETを用いた脳内ドーパミンD2受容体の占有率測定における精度評価

    生駒 洋子, 伊藤 浩, 志田原 美保, 関 千江, 木村 裕一, 須原 哲也, 菅野 巖

    第47回日本核医学会総会 2007年11月4日

  42. 脳内ドーパミントランスポーターリガンド[11C]PE2Iの定量評価法の検討

    関 千江, 伊藤 浩, 生駒 洋子, 志田原 美保, 高野 晶寛, 高橋 英彦, 菅野 巖, 須原 哲也

    第46回日本核医学会総会 2006年11月4日

  43. ,『[F-18]FEDAA1106によるレセプター結合能のパラメトリック画像計算の検討

    志田原 美保, 藤村 洋太, 生駒 洋子, 関 千江, 伊藤 浩, 鈴木 和年, 菅野 巖, 須原 哲也

    第46回日本核医学会総会 2006年11月4日

  44. Bootstrap法を用いたPET受容体計測における定量パラメータ推定精度の評価

    生駒 洋子, 志田原 美保, 関 千江, 伊藤 浩, 須原 哲也, 菅野 巖

    第46回日本核医学会総会 2006年11月4日

  45. PETを用いた脳内受容体結合能の定量精度評価法の検討

    生駒 洋子, 志田原 美保, 伊藤 浩, 関 千江, 菅野 巖, 須原 哲也

    第25回日本医用画像工学会大会 2006年7月21日

  46. 脳血流SPECT画像を用いたアルツハイマー病患者と正常者の弁別読影精度を数値解析で予測する試み

    志田原 美保, 井上 健太郎, 瀧 靖之, 岡田 賢, 後藤 了以, 木之村 重男, 伊藤 浩, 福田 寛, 丸山 将浩, 荒井 啓行

    第45回日本核医学会総会 2005年11月11日

  47. IMP-SPECT検査を用いたアルツハイマー病診断に散乱線補正が及ぼす影響に関する検討

    志田原 美保, 加藤 隆司, 伊藤 浩, 河津 省司, 福田 寛, 伊藤 健吾

    第44回日本核医学会総会 2004年11月4日

  48. AD-tsum法によるアルツハイマー病診断の検討

    加藤 隆司, 伊藤 健吾, 河津 省司, 齋藤 敦子, 籏野 健太郎, 志田原 美保, 桃崎 壮太郎, 川角 保広, 阿部 祐士, 鷲見 幸彦, 新畑 豊, 岩井 克成, 山田 孝子, 加知 輝彦, Kar

    第43回日本核医学会総会 2003年11月27日

  49. 安価で汎用性のあるmotion correciton 装置の開発と実用性の検討

    河津 省司, 志田原 美保, 加藤 隆司, 川角 保徳, 籏野 健太郎, 伊藤 健吾

    第43回日本核医学会総会 2003年11月27日

  50. 脳SPECT検査における画像間格差補正法の比較検討

    志田原 美保, 河津 省司, 加藤 隆司, 加藤 力雄, 長谷川 みち代, 伊藤 健吾

    第43回日本核医学会総会 2003年10月27日

  51. IMP-SPECT検査とSPM解析における画像ベース散乱線補正法の有用性の検討

    志田原 美保, 河津 省司, 加藤 隆司, 渡部 浩司, KyeongMin Kim, 飯田 秀博, 加藤 力雄, 伊藤 健吾

    第43回日本核医学会総会 2003年10月27日

  52. 脳SPECT検査における画像ベース散乱線補正法の開発

    志田原 美保, 河津 省司, 加藤 隆司, 渡部 浩司, KyeongMin Kim, 飯田 秀博, 伊藤 健吾

    第43回日本核医学会総会 2003年10月27日

  53. 健常者の脳糖代謝の加齢性変化に関する検討

    加藤 隆司, 伊藤 健吾, 河津 省司, 齋藤 敦子, 籏野 健太郎, 志田原 美保, 桃崎 壮太郎, 川角 保広, 阿部 祐士, 鷲見 幸彦, 新畑 豊, 岩井 克成, 山田 孝子, 加知 輝彦

    第43回日本核医学会総会 2003年10月27日

  54. 脳酸素摂取率測定のためのO-15標識酸素ガス吸入検査の測定時間最適化

    志田原 美保, 渡部 浩司, KyeongMin Kim, 飯田 秀博

    第42回日本核医学会総会 2002年11月4日

  55. 15O-O2ガス吸入定性早期画像の意義

    志田原 美保, 渡部 浩司, Kyeyong Kim, 飯田 秀博

    第41回日本核医学会総会 2001年10月17日

  56. ECAT EXACTを用いた15O検査システムの構築

    志田原 美保, 渡部 浩司, KyeongMin Kim, 飯田 秀博, 岡 尚嗣, 佐合 正義, 林 拓也, 三宅 義徳, 石田 良雄, 林田 孝平

    第41回日本核医学会総会 2001年10月17日

  57. 99mTc-ECD-ARG 法の再現性の検討

    蜂谷 武憲, 犬上 篤, 飯田 秀博, 志田原 美保

    第40回日本核医学会総会 2000年11月1日

  58. サブウインドウを用いた輪郭抽出法の最適化

    志田原 美保, 渡部 浩司, Kyeyong Kim, 蜂谷 武憲, 飯田 秀博

    第40回日本核医学会総会 2000年11月1日

  59. PRISM-2000 XP を用いた123I-IMP 脳血流SPECTの散乱線除去

    蜂谷 武憲, 犬上 篤, 熊谷 和子, 大村 知巳, 吉田 円, 佐藤 亜結子, 横山 絵里子, 飯田 秀博, 志田原 美保

    第18回動態核医学研究会 2000年7月29日

  60. 99mTc-ECD K1画像定量検査における吸収及び散乱線補正の効果

    志田原 美保, 飯田 秀博, 菅野 巖, 中村 尚司, 蜂谷 武憲

    第39回日本核医学会総会 1999年10月5日

  61. アンフォールディングによる3次元PETの散乱線補正

    志田原 美保, 成田 雄一郎, 藤原 竹彦, 三宅 正泰, 四月朔日, 聖, 中村 尚司

    第38回日本核医学会総会 1998年10月14日

  62. アンフォールディングによる頭部PETの散乱線補正法

    志田原 美保, 成田 雄一郎, 藤原 竹彦, 三宅 正泰, 四月朔日, 聖, 中村尚司

    第37回日本核医学会総会 1997年11月19日

︎全件表示 ︎最初の5件までを表示

産業財産権 1

  1. SPECT断層画像補正方法、システム、およびプログラム

    伊藤健吾, 加藤隆司, 河津省司, 志田原美保

    特許第3660998号

    産業財産権の種類: 特許権

共同研究・競争的資金等の研究課題 15

  1. 認知症モデルマーモセットの産出と評価

    代表, 関 和彦

    2023年4月 ~ 2024年3月

  2. PET創薬デジタルトランスフォーメーションを加速する画像予測技術開発

    志田原美保

    2021年10月 ~ 2023年9月

  3. 複数個体を対象とする動物PET体動補正で実現する無麻酔・非拘束な生体機能評価

    志田原 美保

    2021年7月9日 ~ 2023年3月31日

    詳細を見る 詳細を閉じる

    病態解明・創薬・難治疾患の治療法開発などの基礎研究を目的として、様々な動物種、遺伝子改変動物、病態モデル動物などを対象としたPET(陽電子断層撮影)検査が麻酔下/拘束条件で実施されている。本研究では、放射性マーカーのトラッキング技術と体動補正技術を融合した複数個体を対象とする動物PET検査により、麻酔・拘束具が不要な真にストレスフリー状態の小動物の統計的な生体機能評価の実現に取り組む。 令和3年度は、放射性マーカーのトラッキング基盤技術開発を行った。マーカートラッキング技術開発のため、プナラーイメージング装置で複数のNa-22の密封線源を連動・計測する基礎実験を行った。この実験で得られた2次元ダイナミック画像に含まれる放射性マーカーを画像処理により検知し時系列にマーカー位置を追跡する基本アルゴリズムの構築を行った。その結果、高検出率でマーカー追跡が可能となった。 次年度は、計画中の放射性マーカーの作成、動物用ケージの作成を行い、ストレスフリーラットの生体機能評価実験に向けた検討を進める予定である。

  4. X線透視画像上での物体特定により飛躍的な被ばく量低減を実現する新型IVRシステム

    菊池 洋平, 小谷 光司, 千田 浩一, 志田原 美保, 渡部 浩司, 狩川 大輔, 松原 佳亮, 松山 成男

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2019年4月1日 ~ 2023年3月31日

    詳細を見る 詳細を閉じる

    本研究課題では、まず、X線エネルギー分解画像を取得可能フラットパネル検出器に活用するための半導体検出器の開発を行った。ここでは、テルル化カドミウム(CdTe)、ガリウムヒ素(GaAs)のそれぞれを検出器母材としている。各材料に対しては、通常のフォトリソ技術に基づくプロセスとプリンタブルエレクトロニクス技術のそれぞれを適応しており、これらの作製プロセスの条件抽出などを行った。また、この検出器開発に関連して、検出器からの出力を増幅・処理するための集積回路開発に向けた環境整備を行った。今後、増幅率がスイッチ可能な増幅器の特定用途集積回路(ASIC)の利用可能性について調査する予定である。 また、X線エネルギー分解画像の取得に基づくIVRの低被ばく化のため、低画質X線透視画像の高画質化手法についての技術要素を開発した。この方法論は透視画像中での物体の特定に基づくため、その特定方法についての検討を行った。また、各物体の画像上での占有領域を抽出するための手法を機械学習に基づいて構築した。 本計画の最終段階においては、臨床医が上記の画質改善済み画像を閲覧して、技術全般に関しての主観的評価を実施する予定である。この準備として、視線追跡装置(アイトラッカー)を導入し、体験型実験のための実験体系の基本方針を模索した。この作業は、研究協力者である複数の医師から研究代表者らが提案する評価手法に対する意見を抽出したもので、これによって、上記の主観評価を行うための必要となる要件等が抽出できた。

  5. PET-NIRS融合イメージングによるアルツハイマー病診断の高度化と脳機能の解明

    渡部 浩司, 田代 学, 志田原 美保, 茨木 正信, 松原 佳亮

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2017年4月1日 ~ 2020年3月31日

    詳細を見る 詳細を閉じる

    本研究では、PET装置と光トポグラフィ(NIRS)装置を用いて、脳機能の同時測定を行い、マルチモダリティによる新しい脳機能診断法を開発することを目的とする。 これまで、本研究では、PET撮像とNIRS撮像を別々の時間に収集してきた。これにより、PETによる脳機能とNIRSによって測定された血流量とを同一の空間上にマッピングできることを証明した。 しかし、一つの課題として、まったく同時に測定されていなかったため、PETで測定された脳機能とNIRSで測定された脳血流値が本当に一致しているのかを確定することは不可能である。 実際に、前年度に出版した研究論文において、PETとNIRSの測定値の不一致が見られた。そこで、本年度は、可搬型のNIRS装置を用いて、PETとNIRSの同時測定を行う臨床実験を施行した。被検者にはO-15水を複数回投与し、その間、さまざまなタスクを実施した。そして、NIRSによる脳血流測定を同時に行った。この実験は世界でも初の実験となる。さらに、PETの撮像中の被検者の頭部の動きを光学式トラッキング装置でモニターし、PET画像の動き補正を行う手法と、PET/MRI同時測定装置を用いて、PET画像を同時に撮像したMRI画像をリファレンスとして動き補正を行う方法と比較した。その結果、本研究で利用している光学式トラッキング装置を用いた動き補正システムが高い精度を持っていることが明らかになった。また、アミロイドPET撮像における投与量と画質の関係を調べ、最適な投与量を推定した。特に低い投与量の場合、大きな定量値のエラーが発生することを明らかにした。

  6. アルツハイマー病診断のための脳PET画像の部分容積効果補正法の開発・評価

    志田原 美保, 茨木 正信

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2015年4月1日 ~ 2018年3月31日

    詳細を見る 詳細を閉じる

    研究目的は、アルツハイマー病の診断を目的としたPET検査において、アルツハイマー病に特徴的な病理(アミロイドβ、タウ集積)を反映する脳画像を高精度化することである。このために形態・解剖情報を用いた部分容積効果補正を行うことで画像の定量性を向上させる画像処理手法の確立に取り組んだ。その中で、形態・解剖情報を用いる様々な部分容積効果補正法の誤差伝播特性をシミュレーションで明らかにし、診断能の向上に起因する要因を明らかにし、どのようなアルゴリズムであれば、臨床上有用であるかについてシミュレーションをもとに詳細な検討を行った。解剖情報と周波数領域を利用するハイブリッドな方法が有用であると考えられた。

  7. PETとNIRSの融合による新たな認知症診断法の開発

    渡部 浩司, 田代 学, 久保 均, 四月朔日 聖一, 志田原 美保

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2014年4月1日 ~ 2017年3月31日

    詳細を見る 詳細を閉じる

    本研究は、アルツハイマー病の診断能を飛躍的に向上させるために、PETアミロイドβイメージング剤の新しい診断方法の開発およびPET画像とNIRSデータの融合システムを構築することを目的とする。薬剤の化学形から、脳内への移行しやすさを判断し、得られるPETデータを予測、その診断能を評価するCUI(clinical usefulness index)を導き出した。また、光学式トラッキング装置を用いたPET/NIRS融合測定法を開発し、その有効性を臨床実験により評価した。その結果、PETとNIRSデータが脳内の同座標系に表示され、両モダリティの解析を融合させることができた。

  8. OpenPETによる「その場」がん治療イメージング手法の研究

    山谷 泰賀, 高橋 浩之, 羽石 秀明, 菅 幹生, 河合 秀幸, 志田原 美保, 吉田 英治, 稲玉 直子, 錦戸 文彦, 平野 祥之, 伊藤 浩, 辻 厚至, 稲庭 拓, 小畠 隆行, 川平 洋

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:National Institute of Radiological Sciences

    2013年4月1日 ~ 2016年3月31日

    詳細を見る 詳細を閉じる

    未だ死亡原因一位のがんに対し、近年、陽電子断層撮影法(PET)や重粒子線がん治療などに代表されるように、がんの診断法および治療法それぞれについて大幅な技術革新が行われてきたが、診断と治療の組み合わせがもつポテンシャルについてはほとんど研究されてこなかった。本研究では、PETでみながらの放射線治療やPETでみながらの外科手術の実現を目指し、世界初の開放型PET「OpenPET」を開発した。

  9. タウ画像化プローブの精密機能解析と高性能化研究

    古本 祥三, 岡村 信行, 志田原 美保

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2013年4月1日 ~ 2016年3月31日

    詳細を見る 詳細を閉じる

    本研究では、我々がこれまでに開発を進めてきたアルツハイマー病のタウ病理を画像化するためのPETプローブについて、精密機能解析を基盤としてさらなる性能向上を目指したプローブ構造最適化に取り組んだ。結果として、従来プローブのアリール構造をピリジン構造に変え、側鎖のフロロプロパノールの立体構造をS-エナンチオマー型にすることで、脳内動態性を大幅に向上させ、白質への非特異的集積を低減させることができた。臨床PET研究により、アルツハイマー病患者で、タウ病理の好発部位である海馬傍回や下側頭回に高いプローブ集積を認めた。以上より、目的とするタウプローブの構造最適化を実現できた。

  10. PET脳機能を高精度に定量画像化する形態・解剖情報を用いた画像解析システム

    志田原 美保(古本美保)

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

    研究種目:Grant-in-Aid for Young Scientists (B)

    研究機関:Tohoku University

    2012年4月1日 ~ 2015年3月31日

    詳細を見る 詳細を閉じる

    本研究は、PET検査によって得られる様々な脳機能を高精度に定量画像化するために、形態・解剖情報を積極的に導入し脳機能推定を高精度化することを目指し、MRI画像及び脳アトラスを用いてPET画像特性を向上させるためシステム構築した。また、その有用性を、ドーパミン機能を評価する[11C]raclopride PET検査を想定した15名のヒト脳の数値シミュレーションによって実証し、臨床データにおいても[11C]racloprideの結合能の推定において提案手法が精度を向上させることを確認した。

  11. アミロイドイメージングにおける定量化、統計学的画像解析の方法の確立

    加藤 隆司, 志田原 美保, 伊藤 健吾, 藤原 謙

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:National Center for Geriatrics and Gerontology

    2010年 ~ 2012年

    詳細を見る 詳細を閉じる

    本研究は,BF-227 PETアミロイドイメージグによる脳内アミロイド蛋白集積の精確な評価方法を確立することを目標とした.MRIを使用せず,標準脳BF-227テンプレートを使ってBF-227画像単独で行う解剖学的標準化は,MRIから変換パラメータを得る方法と同等以上の精度があった.標準脳上の共通領域と各個人の組織分離閾値を組み合わせた小脳参照領域の決定方法を用いることで,各診断カテゴリ間のBF-227集積度値の分離を向上させることが出来た.空間分解能補正による部分容積効果の補正は,白質・灰白質の集積の良好な分離ができず,今後のアルゴリズムの改良が必要である.本研究で開発あるいは有効性が確認された方法は,BF-227だけではなく,PiBなど他のアミロイド・イメージング剤への応用も期待される.

  12. PET脳機能画像におけるMRI形態情報との画像シナジーシステムの開発

    志田原 美保

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

    研究種目:Grant-in-Aid for Young Scientists (B)

    研究機関:National Institute of Radiological Sciences

    2009年 ~ 2010年

    詳細を見る 詳細を閉じる

    本研究は、PET脳神経受容体機能の臨床診断において、形態異常部位、形態異常はないが機能異常がみられる部位などを今まで以上に的確に診断するために、MRIによる解剖情報を積極的に導入し様々な脳機能を高精度に画像化することを目指し、MRI画像の形態情報を用いてPET画像特性を向上させるためシステム構築した。また、その有用性を、脳を模擬した数値シミュレーションによって実証した。

  13. 微小採血及び無採血化を含むPETによるマウス神経受容体定量画像手法の構築

    木村 裕一, 外山 宏, 北村 圭司, 樋口 真人, 志田原 美保, 本谷 秀堅, 関 千江, 西本 尚弘, 和田 康弘, 長縄 美香, 坂口 和也

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:National Institute of Radiological Sciences

    2008年 ~ 2010年

    詳細を見る 詳細を閉じる

    本科研費では、小動物に対する微小体積の血中放射能濃度測定システムの開発、及び無採血化のためのデータ処理で必要となる小動物からの陽電子断層撮影画像(PET)データに対する雑音削除アルゴリズムの開発を行った。システム開発では、数[μL]の血液に対して、血漿の分離、血漿及び全血の体積の測定、放射能の測定を行うためのシステムを開発した。その結果製品として発売し得るレベルでの完成を見た。また、事後確率最大化規範に基づいた雑音除去アルゴリズムを開発し、その実用性を示した。

  14. 定量的なPET脳神経受容体機能画像化のための画像処理システム

    志田原 美保

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

    研究種目:Grant-in-Aid for Young Scientists (B)

    研究機関:National Institute of Radiological Sciences

    2007年 ~ 2008年

    詳細を見る 詳細を閉じる

    本研究は、陽電子断層撮影(PET)を用いた脳神経受容体機能定量画像の高精度化を目指し、ガウシアンノイズ除去及び部分容積効果補正に関してシステムを構築しその有用性を数値シミュレーションで実証した。また、これらの技術が必要とされている臨床例(脳内ドーパミンD2受容体結合能や脳萎縮が進行したアルツハイマー病患者の糖代謝画像など)への適応を行い、その有用性を確認した。

  15. 核医学診断のための正常者脳画像データベースの構築とその応用に関する研究

    古本 美保

    2003年 ~ 2005年

    詳細を見る 詳細を閉じる

    本研究の目的は、放射性同位元素を用いた核医学検査の高精度診断に必要不可欠な大規模な正常者脳画像データベースを構築するため、データを募る各病院施設で撮影された画像間の較差を補正する技術を開発することである。本年度は、昨年度開発した画像処理に由来する画像間格差補正法の評価、また正常者データベースを用いた健常者、疾患者の自動弁別法の開発を行った。 1)散乱線補正に由来する画像間較差に対して提案手法が利用できることを確認した。 この研究成果は、9月European Annual Meeting of Society of Nuclear Medicine(ヘルシンキ)、11月日本核医学会総会(京都)において発表され、論文として、ElsevierによるICS Congress Series 1265に掲載、European Journal of Nuclear Medicine and Molecular Imagingにacceptされた。また昨年出願した特許「SPECT断層画像補正方法,システム,およびプログラム」(出願番号2003-169809)に関しても査定が終了し特許取得が確定している。 2)正常者データベースを用いた健常者、疾患者核医学画像の自動弁別法を開発した。 本年度は、核医学画像に対応した心理物理学の手法を用いたアルゴリズムの導入及びプログラム開発をおこない、自動画像弁別システムを構築した。この自動弁別法の導入により我々が開発している画像及び施設間較差補正方法が病気の診断にどれだけ有用であるか医師の診断を客観的に予測し評価できるようになる。この研究については、臨床の健常者、疾患データを用いた評価を次年度にひきつづき行う計画であり、またIEEE Nuclear Science and Medical Imaging Conferenceにおいてその成果を報告予定である。

︎全件表示 ︎最初の5件までを表示

社会貢献活動 2

  1. 第16回核医学専門技師研修セミナー (画像処理2)

    2023年4月17日 ~ 2023年5月27日

  2. 第7回放射線治療・物理学セミナー(放射線基礎物理)

    2019年3月24日 ~

その他 3

  1. Partial volume correction using Structural-Functional Synergistic Resolution Recovery: comparison with the geometric transfer matrix method

    詳細を見る 詳細を閉じる

    Partial volume correction using Structural-Functional Synergistic Resolution Recovery: comparison with the geometric transfer matrix method

  2. Quantification of opioid receptor availability following spontaneous epileptic seizures: correction of [11C]diprenorphine PET data for the partial-volume effec

    詳細を見る 詳細を閉じる

    Quantification of opioid receptor availability following spontaneous epileptic seizures: correction of [11C]diprenorphine PET data for the partial-volume effec

  3. 核医学検査による腫瘍・血流イメージングに適応可能な汎用型自動診断法の開発

    詳細を見る 詳細を閉じる

    核医学検査による腫瘍・血流イメージングに適応可能な汎用型自動診断法の開発