博士（保健学）, 九州大学, Mar. 2018

修士（医科学）, 横浜市立大学, Mar. 2014

SPECT

神経変性疾患

分子イメージング

Nuclear medicine

PET

Neuloimaging

放射線管理学

Radiological technology

Life Science, Radiological sciences

Bachelor's degree program, Departments of Health Sciences, School of Medicine

Master's degree program, Graduate School of Biomedical Science and Engineering

Doctoral (PhD) degree program, Graduate School of Biomedical Science and Engineering

Apr. 2026, 日本放射線技術学会, 2025年度 滝内賞
我妻慧

Apr. 2025, 第81回日本放射線技術学会総会学術大会, 学生賞 優秀賞

Apr. 2024, 第80回日本放射線技術学会総会学術大会, CyPos賞 銅賞

Apr. 2024, 第80回日本放射線技術学会総会学術大会, 学生賞 優秀賞

Dec. 2023, 日本放射線技術学会東京支部・関東支部, 東京・関東支部合同研究発表大会2023優秀演題賞
我妻慧

Sep. 2023, 日本核医学技術学会, 国際研究奨励賞
我妻慧

May 2023, 日本放射線技術学会東京支部, 第76回東京支部春期学術大会 学術奨励賞

May 2023, 日本放射線技術学会東京支部, 第76回東京支部春期学術大会 新人研究奨励賞

May 2022, 日本放射線技術学会, 第78回日本放射線技術学会総会学術大会 学生賞 優秀賞

May 2022, 日本放射線技術学会東京支部, 第75回東京支部学術大会 新人研究奨励賞

Apr. 2022, 日本放射線技術学会東京支部, 東京支部 Reserch Award

Nov. 2020, 日本核医学会, 第17回日本核医学会研究奨励賞
我妻慧

May 2020, 日本放射線技術学会第76回総会学術大会, Bronze Award

May 2020, 日本放射線技術学会第76回総会学術大会, Gold Award

Jun. 2019, 米国核医学会（SNMMI）2019, Technologist Travel Grant Award 2019

Apr. 2019, 日本放射線技術学会第75回総会学術大会, Bronze Award

Oct. 2018, 日本放射線技術学会第46回秋季学術大会, 銀賞

Aug. 2018, 国際医療福祉大学学会第8回学術大会, 優秀演題賞

Jun. 2018, 米国核医学会（SNMMI）2018, Technologist Travel Grant Award 2018
我妻慧

Apr. 2018, 日本放射線技術学会第74回総会学術大会, Bronze Award
我妻慧

Apr. 2018, 第12回世界核医学会（WFNMB 2018）, Best Poster Award
我妻慧

Nov. 2017, 日本核医学会, 2017年久田賞 銀賞

Nov. 2017, 日本放射線技術学会, 平成29年度 研究奨励賞・技術賞奨励賞（核医学分野）
我妻慧

Oct. 2017, 日本放射線技術学会第45回秋季学術大会, 優秀演題賞

Apr. 2017, 日本放射線技術学会第73回総会学術大会, Gold Award
我妻慧

Apr. 2015, 日本放射線技術学会第71回総会学術大会, Bronze Award

Nov. 2014, 日本放射線技術学会, 平成26年度 研究奨励賞・技術新人賞（核医学分野）
我妻慧

Registration accuracy of amyloid/tau-PET to brain MRI using modified SPM method
Yuma Iwao; Go Akamatsu; Muneyuki Sakata; Kei Wagatsuma; Kenji Ishii; Taiga Yamaya; Miwako Takahashi
Annals of Nuclear Medicine, Springer Science and Business Media LLC, 04 Feb. 2026, [Peer-reviewed]
English, Scientific journal

Quantitative validation of data-driven motion correction for brain PET using phantom with motion generator system
Yuto Kamitaka; Muneyuki Sakata; Keiichi Oda; Akie Katsuki; Hirofumi Kawakami; Kei Wagatsuma; Masato Kobayashi; Kenji Ishii
EJNMMI Physics, 13, 1, Springer Science and Business Media LLC, 16 Dec. 2025
Scientific journal

Impact of scale point selection on absorbed dose estimation in hybrid dosimetry for 177Lu-DOTATATE therapy
Noriaki Miyaji; Kenta Miwa; Naochika Akiya; Kaito Wachi; Arata Komatsu; Masaki Masubuchi; Kosuke Yamashita; Kei Wagatsuma; Tensho Yamao; Takayuki Yagihashi; Taro Murai
Health and Technology, 16, 2, 325, 336, Springer Science and Business Media LLC, 01 Aug. 2025
Scientific journal

Innovations in clinical PET image reconstruction: advances in Bayesian penalized likelihood algorithm and deep learning
Kenta Miwa; Tensho Yamao; Fumio Hashimoto; Noriaki Miyaji; Yuto Kamitaka; Masaki Masubuchi; Taisuke Murata; Tokiya Yoshii; Rinya Kobayashi; Shohei Fukuda; Naochika Akiya; Kaito Wachi; Kei Wagatsuma
Annals of Nuclear Medicine, 39, 9, 875, 898, Springer Science and Business Media LLC, 18 Jul. 2025, [Peer-reviewed], [Invited]
English, Scientific journal, Abstract

Recent advances in PET image reconstruction have focused on achieving high image quality and quantitative accuracy. Bayesian penalized likelihood (BPL) algorithms, such as Q.Clear and HYPER Iterative that have been integrated into commercial PET systems offer robust image noise suppression and edge preservation through regularization. In parallel, methods based on deep learning such as SubtlePET, AiCE, uAI^® HYPER DLR, and Precision DL have emerged primarily as post-processing techniques. They use trained convolutional neural networks to reduce image noise while preserving lesion contrast. These methods have reduced image acquisition times or reduced radiotracer doses while maintaining diagnostic confidence. uAI^® HYPER DPR represents a hybrid approach by embedding deep learning in iterative reconstruction. This review summarizes the technical principles and the clinical performance of BPL and deep learning-based PET reconstruction algorithms, and discusses key considerations such as image quality and quantitative accuracy of PET images. This review should deepen understanding of advanced PET image reconstruction techniques and accelerate their clinical implementation across diverse PET imaging applications.

Effects of a deep learning-based image quality enhancement method on a digital-BGO PET/CT system for 18F-FDG whole-body examination
Kenta Miwa; Shin Yamagishi; Shun Kamitaki; Kouichi Anraku; Shun Sato; Tensho Yamao; Noriaki Miyaji; Kaito Wachi; Naochika Akiya; Kei Wagatsuma; Kazuhiro Oguchi
EJNMMI Physics, 12, 1, Springer Science and Business Media LLC, 28 Mar. 2025, [Peer-reviewed]
English, Scientific journal, Abstract

Background

The digital-BGO PET/CT system, Omni Legend 32, incorporates modified block sequential regularized expectation maximization (BSREM) image reconstruction and a deep learning-based time-of-flight (TOF)-like image quality enhancement process called Precision DL (PDL). The present study aimed to define the fundamental characteristics of PDL using phantom and clinical images.

Methods

A NEMA IEC body phantom was scanned using the Omni Legend 32 PET/CT system. All PET/CT images were acquired over 60 and 90 s per bed position, with a 384 × 384 matrix. Phantom images were reconstructed using OSEM + PSF and BSREM at β values of 100–1,000, combined with low (LPDL), medium (MPDL), and high (HPDL) PDL. We evaluated contrast recovery, background variability, and the contrast-to-noise ratio (CNR) of a 10 mm hot sphere. Thirty clinical whole-body ¹⁸F-FDG PET/CT examinations were included. Clinical images were reconstructed using OSEM + PSF and BSREM at β values of 200, 300, 400, 500, and 600, determined based on findings from the phantom study, combined with the three PDL models. Noise levels, mean SUV (SUV_mean), and the signal-to-noise ratio (SNR) of the liver as well as signal-to-background ratios (SBR) and maximum SUV (SUV_max) of lesions were evaluated. Two blinded readers evaluated visual image quality and rated several aspects to complement the analysis.

Results

Contrast recovery and background variability decreased as the β value increased. This trend was consistent even when PDL processing was added to BSREM. Increased strength of the PDL models led to higher CNR. Noise levels decreased as a function of increasing β values in BSREM, resulting in a higher SNR, but lower SBR. Combining PDL with BSREM resulted in all β values producing better results in terms of noise, SBR, and SNR than OSEM + PSF. As the PDL increased (LPDL < MPDL < HPDL), noise levels, SBR, and SNR became higher. The β values of 400, 200, 300, and 300 for BSREM, LPDL, MPDL, and HPDL, respectively, resulted in noise equivalent to OSEM + PSF but significantly increased the SUV_max (9%, 15%, 18%, and 27%), SBR (16%, 17%, 20%, and 32%), and SNR (17%, 19%, 31%, and 36%), respectively. The visual evaluation of image quality yielded similar scores across BSREM + PDL reconstructions, although BSREM with β = 600 combined with MPDL delivered the best overall image quality and total mean score.

Conclusion

The combination of BSREM and PDL significantly enhanced the SUV_max of lesions and image quality compared with OSEM + PSF. A combination of BSREM at β values of 500–600 and MPDL is recommended for oncological whole-body PET/CT imaging when using PDL on the Omni Legend.

Radiation Dose Considerations for Breast Sonographers Following ^99mTc-HMDP Bone Scan Administration
Ryota Tsukada; Kei Wagatsuma; Hiroaki Suzuki
Japanese Journal of Radiological Technology, 80, 9, 937, 942, Japanese Society of Radiological Technology, Sep. 2024, [Peer-reviewed]
Japanese, Scientific journal

Phantom test procedures for a new neuro-oncological amino acid PET tracer: [18F]fluciclovine
Kaede Tsuzura; Kei Wagatsuma; Yuto Kamitaka; Kenta Miwa; Noriaki Miyaji; Takashi Kamiya; Noriyo Yokotsuka; Kenji Ishii
Annals of Nuclear Medicine, Springer Science and Business Media LLC, 29 Aug. 2024, [Peer-reviewed], [Corresponding author]
English, Scientific journal

Optimization of penalization function in Bayesian penalized likelihood reconstruction algorithm for [18F]flutemetamol amyloid PET images
Shohei Fukuda; Kei Wagatsuma; Kenta Miwa; Yu Yakushiji; Yuto Kamitaka; Tensho Yamao; Noriaki Miyaji; Kenji Ishii
Physical and Engineering Sciences in Medicine, Springer Science and Business Media LLC, 12 Aug. 2024, [Peer-reviewed], [Corresponding author]
English, Scientific journal, 31628848

Development of a novel phantom for tau PET imaging
Kei Wagatsuma; Kenta Miwa; Tensho Yamao; Yuto Kamitaka; Go Akamatsu; Kanta Nakajima; Noriaki Miyaji; Kenji Ishibashi; Kenji Ishii
Physica Medica, 123, 103399, 103399, Elsevier BV, Jul. 2024, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, 31628848;42402738

Phantom and clinical evaluation of the Bayesian penalised likelihood reconstruction algorithm Q.Clear without PSF correction in amyloid PET images
Kei Wagatsuma; Muneyuki Sakata; Kenta Miwa; Yumi Hamano; Hirofumi Kawakami; Yuto Kamitaka; Tensho Yamao; Noriaki Miyaji; Kenji Ishibashi; Tetsuro Tago; Jun Toyohara; Kenji Ishii
EJNMMI Physics, 11, 1, 37, Springer Science and Business Media LLC, 22 Apr. 2024, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, Abstract

Purpose

Bayesian penalised likelihood (BPL) reconstruction, which incorporates point-spread-function (PSF) correction, provides higher signal-to-noise ratios and more accurate quantitation than conventional ordered subset expectation maximization (OSEM) reconstruction. However, applying PSF correction to brain PET imaging is controversial due to Gibbs artefacts that manifest as unpredicted cortical uptake enhancement. The present study aimed to validate whether BPL without PSF would be useful for amyloid PET imaging.

Methods

Images were acquired from Hoffman 3D brain and cylindrical phantoms for phantom study and 71 patients administered with [¹⁸F]flutemetamol in clinical study using a Discovery MI. All images were reconstructed using OSEM, BPL with PSF correction, and BPL without PSF correction. Count profile, %contrast, recovery coefficients (RCs), and image noise were calculated from the images acquired from the phantoms. Amyloid β deposition in patients was visually assessed by two physicians and quantified based on the standardised uptake value ratio (SUVR).

Results

The overestimated radioactivity in profile curves was eliminated using BPL without PSF correction. The %contrast and image noise decreased with increasing β values in phantom images. Image quality and RCs were better using BPL with, than without PSF correction or OSEM. An optimal β value of 600 was determined for BPL without PSF correction. Visual evaluation almost agreed perfectly (κ = 0.91–0.97), without depending on reconstruction methods. Composite SUVRs did not significantly differ between reconstruction methods.

Conclusion

Gibbs artefacts disappeared from phantom images using the BPL without PSF correction. Visual and quantitative evaluation of [¹⁸F]flutemetamol imaging was independent of the reconstruction method. The BPL without PSF correction could be the standard reconstruction method for amyloid PET imaging, despite being qualitatively inferior to BPL with PSF correction for [¹⁸F]flutemetamol amyloid PET imaging.

Deep Learning-Driven Estimation of Centiloid Scales from Amyloid PET Images with 11C-PiB and 18F-Labeled Tracers in Alzheimer’s Disease
Tensho Yamao; Kenta Miwa; Yuta Kaneko; Noriyuki Takahashi; Noriaki Miyaji; Koki Hasegawa; Kei Wagatsuma; Yuto Kamitaka; Hiroshi Ito; Hiroshi Matsuda
Brain Sciences, 14, 4, 406, 406, MDPI AG, 21 Apr. 2024, [Peer-reviewed]
English, Scientific journal, Background: Standard methods for deriving Centiloid scales from amyloid PET images are time-consuming and require considerable expert knowledge. We aimed to develop a deep learning method of automating Centiloid scale calculations from amyloid PET images with 11C-Pittsburgh Compound-B (PiB) tracer and assess its applicability to 18F-labeled tracers without retraining. Methods: We trained models on 231 11C-PiB amyloid PET images using a 50-layer 3D ResNet architecture. The models predicted the Centiloid scale, and accuracy was assessed using mean absolute error (MAE), linear regression analysis, and Bland–Altman plots. Results: The MAEs for Alzheimer’s disease (AD) and young controls (YC) were 8.54 and 2.61, respectively, using 11C-PiB, and 8.66 and 3.56, respectively, using 18F-NAV4694. The MAEs for AD and YC were higher with 18F-florbetaben (39.8 and 7.13, respectively) and 18F-florbetapir (40.5 and 12.4, respectively), and the error rate was moderate for 18F-flutemetamol (21.3 and 4.03, respectively). Linear regression yielded a slope of 1.00, intercept of 1.26, and R2 of 0.956, with a mean bias of −1.31 in the Centiloid scale prediction. Conclusions: We propose a deep learning means of directly predicting the Centiloid scale from amyloid PET images in a native space. Transferring the model trained on 11C-PiB directly to 18F-NAV4694 without retraining was feasible.

Impact of [11C]methionine PET with Bayesian penalized likelihood reconstruction on glioma grades based on new WHO 2021 classification
Kei Wagatsuma; Kensuke Ikemoto; Motoki Inaji; Yuto Kamitaka; Shoko Hara; Kaoru Tamura; Kenta Miwa; Kaede Tsuzura; Taisei Tsuruki; Noriaki Miyaji; Kenji Ishibashi; Kenji Ishii
Annals of Nuclear Medicine, 38, 5, 400, 407, Springer Science and Business Media LLC, 11 Mar. 2024, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal

Impact of irregular waveforms on data-driven respiratory gated PET/CT images processed using MotionFree algorithm
Noriaki Miyaji; Kenta Miwa; Kosuke Yamashita; Kazuki Motegi; Kei Wagatsuma; Yuto Kamitaka; Tensho Yamao; Mitsutomi Ishiyama; Takashi Terauchi
Annals of Nuclear Medicine, 37, 12, 665, 674, Springer Science and Business Media LLC, 05 Oct. 2023, [Peer-reviewed]
English, Scientific journal

Toward standardization of tau PET imaging corresponding to various tau PET tracers: a multicenter phantom study
Kei Wagatsuma; Kenta Miwa; Go Akamatsu; Tensho Yamao; Yuto Kamitaka; Minoru Sakurai; Naotoshi Fujita; Kohei Hanaoka; Hiroshi Matsuda; Kenji Ishii
Annals of Nuclear Medicine, 37, 9, 494, 503, Springer Science and Business Media LLC, 27 May 2023, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal

Impact of γ factor in the penalty function of Bayesian penalized likelihood reconstruction (Q.Clear) to achieve high-resolution PET images
Kenta Miwa; Tokiya Yoshii; Kei Wagatsuma; Shogo Nezu; Yuto Kamitaka; Tensho Yamao; Rinya Kobayashi; Shohei Fukuda; Yu Yakushiji; Noriaki Miyaji; Kenji Ishii
EJNMMI Physics, 10, 1, Springer Science and Business Media LLC, 22 Jan. 2023, [Peer-reviewed]
English, Scientific journal, Abstract

Background

The Bayesian penalized likelihood PET reconstruction (BPL) algorithm, Q.Clear (GE Healthcare), has recently been clinically applied to clinical image reconstruction. The BPL includes a relative difference penalty (RDP) as a penalty function. The β value that controls the behavior of RDP determines the global strength of noise suppression, whereas the γ factor in RDP controls the degree of edge preservation. The present study aimed to assess the effects of various γ factors in RDP on the ability to detect sub-centimeter lesions.

Methods

All PET data were acquired for 10 min using a Discovery MI PET/CT system (GE Healthcare). We used a NEMA IEC body phantom containing spheres with inner diameters of 10, 13, 17, 22, 28 and 37 mm and 4.0, 5.0, 6.2, 7.9, 10 and 13 mm. The target-to-background ratio of the phantom was 4:1, and the background activity concentration was 5.3 kBq/mL. We also evaluated cold spheres containing only non-radioactive water with the same background activity concentration. All images were reconstructed using BPL + time of flight (TOF). The ranges of β values and γ factors in BPL were 50–600 and 2–20, respectively. We reconstructed PET images using the Duetto toolbox for MATLAB software. We calculated the % hot contrast recovery coefficient (CRC_hot) of each hot sphere, the cold CRC (CRC_cold) of each cold sphere, the background variability (BV) and residual lung error (LE). We measured the full width at half maximum (FWHM) of the micro hollow hot spheres ≤ 13 mm to assess spatial resolution on the reconstructed PET images.

Results

The CRC_hot and CRC_cold for different β values and γ factors depended on the size of the small spheres. The CRC_hot, CRC_cold and BV increased along with the γ factor. A 6.2-mm hot sphere was obvious in BPL as lower β values and higher γ factors, whereas γ factors ≥ 10 resulted in images with increased background noise. The FWHM became smaller when the γ factor increased.

Conclusion

High and low γ factors, respectively, preserved the edges of reconstructed PET images and promoted image smoothing. The BPL with a γ factor above the default value in Q.Clear (γ factor = 2) generated high-resolution PET images, although image noise slightly diverged. Optimizing the β value and the γ factor in BPL enabled the detection of lesions ≤ 6.2 mm.

Dedicated phantom tools using traceable 68Ge/68Ga point-like sources for dedicated-breast PET and positron emission mammography scanners
Mio Okamoto; Tomoyuki Hasegawa; Keiichi Oda; Hiroki Miyatake; Kei Kikuchi; Yusuke Inoue; Yoko Satoh; Yuichi Inaoka; Masami Kawamoto; Koji Shima; Kenji Kanbayashi; Miho Yoshii; Tomoyuki Kanno; Kei Wagatsuma; Masatoshi Hashimoto
Radiological Physics and Technology, 16, 1, 49, 56, Springer Science and Business Media LLC, 09 Jan. 2023, [Peer-reviewed]
English, Scientific journal

Determination of a reliable assessment for occupational eye lens dose in nuclear medicine
Noriaki Miyaji; Kenta Miwa; Takashi Iimori; Kei Wagatsuma; Hiroyuki Tsushima; Noriyo Yokotsuka; Taisuke Murata; Tetsuharu Kasahara; Takashi Terauchi
Journal of Applied Clinical Medical Physics, 23, 8, e13713, Wiley, Jul. 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal, The most recent statement published by the International Commission on Radiological Protection describes a reduction in the maximum allowable occupational eye lens dose from 150 to 20 mSv/year (averaged over 5-year periods). Exposing the eye lens to radiation is a concern for nuclear medicine staff who handle radionuclide tracers with various levels of photon energy. This study aimed to define the optimal dosimeter and means of measuring the amount of exposure to which the eye lens is exposed during a routine nuclear medicine practice. A RANDO human phantom attached to Glass Badge and Luminess Badge for body or neck, DOSIRIS and VISION for eyes, and nanoDot for body, neck, and eyes was exposed to 99m Tc, 123 I, and 18 F radionuclides. Sealed syringe sources of each radionuclide were positioned 30 cm from the abdomen of the phantom. Estimated exposure based on measurement conditions (i.e., air kerma rate constants, conversion coefficient, distance, activity, and exposure time) was compared measured dose equivalent of each dosimeter. Differences in body, neck, and eye lens dosimeters were statistically analyzed. The 10-mm dose equivalent significantly differed between the Glass Badge and Luminess Badge for the neck, but these were almost equivalent at the body. The 0.07-mm dose equivalent for the nanoDot dosimeters was greatly overestimated compared to the estimated exposure of 99m Tc and 123 I radionuclides. Measured dose equivalents of exposure significantly differed between the body and eye lens dosimeters with respect to 18 F. Although accurately measuring radiation exposure to the eye lenses of nuclear medicine staff is conventionally monitored using dosimeters worn on the chest or abdomen, eye lens dosimeters that provide a 3-mm dose equivalent near the eye would be a more reliable means of assessing radiation doses in the mixed radiation environment of nuclear medicine.

Decreased imaging time of amyloid PET using [18F]florbetapir can maintain quantitative accuracy
Kei Wagatsuma; Kenji Ishibashi; Masashi Kameyama; Muneyuki Sakata; Kenta Miwa; Yuto Kamitaka; Kenji Ishii
Radiological Physics and Technology, 15, 2, 116, 124, Springer Science and Business Media LLC, Jun. 2022, [Peer-reviewed], [Lead author, Corresponding author], [Domestic magazines]
English, Scientific journal, Shortening the amount of time required to acquire amyloid positron emission tomography (PET) brain images while maintaining the accuracy of quantitative evaluation would help to overcome motion artifacts associated with Alzheimer's disease patients. The present study aimed to validate the quantitative accuracy of [18F]florbetapir ([18F]FBP) imaging over a shorter acquisition duration. Forty participants were injected with [18F]FBP, and PET images were acquired for 50-55, 50-60, and 50-70 min after injection. Three physicians visually assessed the reprocessed [18F]FBP images using a binary scale to classify them as amyloid β (Aβ) negative or positive. A mean composite standard uptake value ratio (cSUVR) > 1.075 was defined as Aβ-positive based on receiver operating characteristic curves. Inter-reader and inter-acquisition duration agreements with visual assessment were evaluated using Cohen's kappa (κ). Binary visual discrimination of 102 for the 120 [18F]FBP images, was consistent among the three readers. Sixteen, sixteen, and fourteen of the 40 [18F]FBP images acquired for 50-55, 50-60, and 50-70 min after injection, respectively, were deemed Aβ-positive by visual assessment. The inter-rater agreement was high, and the inter-acquisition duration agreement was almost perfect. The cSUVR did not change significantly among the acquisition durations, and the acquisition duration did not affect the outcome of discrimination based on the cSUVR cutoff. A shorter acquisition duration changed the visual assessment outcomes. Stable quantitative values were derived from [18F]FBP images acquired within 5 min. cSUVR helped to improve the performance and confidence in the outcomes of visual assessment.

Determination of optimal regularization factor in Bayesian penalized likelihood reconstruction of brain PET images using [ ¹⁸ F]FDG and [ ¹¹ C]PiB
Kei Wagatsuma; Kenta Miwa; Yuto Kamitaka; Emiya Koike; Tensho Yamao; Tokiya Yoshii; Rinya Kobayashi; Shogo Nezu; Yuta Sugamata; Noriaki Miyaji; Etsuko Imabayashi; Kenji Ishibashi; Jun Toyohara; Kenji Ishii
Medical Physics, 49, 5, 2995, 3005, Wiley, May 2022, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
English, Scientific journal, PURPOSE: The Bayesian penalized likelihood (BPL) reconstruction algorithm, Q.Clear, can achieve a higher signal-to-noise ratio on images and more accurate quantitation than ordered subset-expectation maximization (OSEM). The reconstruction parameter (β) in BPL requires optimization according to the radiopharmaceutical tracer. The present study aimed to define the optimal β value in BPL required to diagnose Alzheimer disease from brain positron emission tomography (PET) images acquired using 18 F-fluoro-2-deoxy-D-glucose ([18 F]FDG) and 11 C-labeled Pittsburg compound B ([11 C]PiB). METHODS: Images generated from Hoffman 3D brain and cylindrical phantoms were acquired using a Discovery PET/computed tomography (CT) 710 and reconstructed using OSEM + time-of-flight (TOF) under clinical conditions and BPL + TOF (β = 20-1000). Contrast was calculated from images generated by the Hoffman 3D brain phantom, and noise and uniformity were calculated from those generated by the cylindrical phantom. Five cognitively healthy controls and five patients with Alzheimer disease were assessed using [18 F]FDG and [11 C]PiB PET to validate the findings from the phantom study. The β values were restricted by the findings of the phantom study, then one certified nuclear medicine physician and two certified nuclear medicine technologists visually determined optimal β values by scoring the quality parameters of image contrast, image noise, cerebellar stability, and overall image quality of PET images from 1 (poor) to 5 (excellent). RESULTS: The contrast in BPL satisfied the Japanese Society of Nuclear Medicine (JSNM) criterion of ≥55% and exceeded that of OSEM at ranges of β = 20-450 and 20-600 for [18 F]FDG and [11 C]PiB, respectively. The image noise in BPL satisfied the JSNM criterion of ≤15% and was below that in OSEM when β = 150-1000 and 400-1000 for [18 F]FDG and [11 C]PiB, respectively. The phantom study restricted the ranges of β values to 100-300 and 300-500 for [18 F]FDG and [11 C]PiB, respectively. The BPL scores for gray-white matter contrast and image noise, exceeded those of OSEM in [18 F]FDG and [11 C]PiB images regardless of β values. Visual evaluation confirmed that the optimal β values were 200 and 450 for [18 F]FDG and [11 C]PiB, respectively. CONCLUSIONS: The BPL achieved better image contrast and less image noise than OSEM, while maintaining quantitative standardized uptake value ratios (SUVR) due to full convergence, more rigorous noise control, and edge preservation. The optimal β values for [18 F]FDG and [11 C]PiB brain PET were apparently 200 and 450, respectively. The present study provides useful information about how to determine optimal β values in BPL for brain PET imaging.

Possibility of Enlargement in Left Medial Temporal Areas Against Cerebral Amyloid Deposition Observed During Preclinical Stage
Etsuko Imabayashi; Kenji Ishii; Jun Toyohara; Kei Wagatsuma; Muneyuki Sakata; Tetsuro Tago; Kenji Ishibashi; Narumi Kojima; Noriyuki Kohda; Aya M. Tokumaru; Hunkyung Kim
Frontiers in Aging Neuroscience, 14, Frontiers Media SA, Apr. 2022, [Peer-reviewed]
Scientific journal, Neurodegenerative changes in the preclinical stage of Alzheimer’s disease (AD) have recently been the focus of attention because they may present a range of treatment opportunities. A total of 134 elderly volunteers who lived in a local community were investigated and grouped into preclinical and mild cognitive impairment stages according to the Clinical Dementia Rating test; we also estimated amyloid deposition in the brain using positron emission tomography (PET). A significant interaction between clinical stage and amyloid PET positivity on cerebral atrophy was observed in the bilateral parietal lobe, parahippocampal gyri, hippocampus, fusiform gyrus, and right superior and middle temporal gyri, as previously reported. Early AD-specific voxel of interest (VOI) analysis was also applied and averaged Z-scores in the right, left, bilateral, and right minus left medial temporal early AD specific area were computed. We defined these averaged Z-scores in the right, left, bilateral, and right minus left early AD specific VOI in medial temporal area as R-MedT-Atrophy-score, L-MedT-Atrophy-score, Bil-MedT-Atrophy-score, and R_L-MedT-Atrophy-score, respectively. It revealed that the R_L-MedT-Atrophy-scores were significantly larger in the amyloid-positive than in the amyloid-negative cognitively normal (CN) elderly group, that is, the right medial temporal areas were smaller than left in amyloid positive CN group and these left-right differences were significantly larger in amyloid positive than amyloid negative CN elderly group. The L-MedT-Atrophy-score was slightly larger (p = 0.073), that is, the left medial temporal area was smaller in the amyloid-negative CN group than in the amyloid-positive CN group. Conclusively, the left medial temporal area could be larger in CN participants with amyloid deposition than in those without amyloid deposition. The area under the receiver operating characteristic curve for differentiating amyloid positivity among CN participants using the R_L-MedT-Atrophy-scores was 0.73; the sensitivity and specificity were 0.828 and 0.606, respectively. Although not significant, a negative correlation was observed between the composite cerebral standardized uptake value ratio in amyloid PET images and L-MedT-Atrophy-score in CN group. The left medial temporal volume might become enlarged because of compensatory effects against AD pathology occurring at the beginning of the amyloid deposition.

Adenosine A 2A Receptor Occupancy by Caffeine After Coffee Intake in Parkinson's Disease
Kenji Ishibashi; Yoshiharu Miura; Kei Wagatsuma; Jun Toyohara; Kiichi Ishiwata; Kenji Ishii
Movement Disorders, 37, 4, 853, 857, Wiley, Apr. 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal, BACKGROUND: Coffee intake can decrease the risk for Parkinson's disease (PD). Its beneficial effects are allegedly mediated by caffeine through adenosine A2A receptor (A2A R) antagonist action. OBJECTIVE: We aimed to calculate occupancy rates of striatal A2A Rs by caffeine after coffee intake in PD. METHODS: Five patients with PD underwent 11 C-preladenant positron emission tomography scanning at baseline and after intake of coffee containing 129.5 mg (n = 3) or 259 mg (n = 2) of caffeine. Concurrently, serum caffeine levels were measured. RESULTS: The mean serum caffeine level (μg/mL) was 0.374 at baseline and increased to 4.48 and 8.92 by 129.5 and 259 mg of caffeine, respectively. The mean occupancy rates of striatal A2A Rs by 129.5 and 259 mg of caffeine were 54.2% and 65.1%, respectively. CONCLUSIONS: A sufficient A2A R occupancy can be obtained by drinking a cup of coffee, which is equivalent to approximately 100 mg of caffeine. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Test–retest reproducibility of cerebral adenosine A2A receptor quantification using [11C]preladenant
Jun Toyohara; Muneyuki Sakata; Kei Wagatsuma; Tetsuro Tago; Kenji Ishibashi; Kenji Ishii; Philip Elsinga; Kiichi Ishiwata
Annals of Nuclear Medicine, 36, 1, 15, 23, Springer Science and Business Media LLC, Jan. 2022, [Peer-reviewed], [Domestic magazines]
English, Scientific journal, OBJECTIVE: To evaluate the reproducibility of cerebral adenosine A2A receptor (A2AR) quantification using [11C]preladenant ([11C]PLN) and PET in a test-retest study. METHODS: Eight healthy male volunteers were enrolled. Dynamic 90 min PET scans were performed twice at the same time of the day to avoid the effect of diurnal variation. Subjects refrained from caffeine from 12 h prior to scanning, and serum caffeine was measured before radioligand injection. Arterial blood was sampled repeatedly during scanning and the fraction of the parent compound in plasma was determined. Total distribution volume (VT) was estimated using 1- and 2-tissue compartment models (1-TCM and 2-TCM, respectively) and Logan graphical analysis (Logan plot) (t* = 30 min). Plasma-free fraction (fP) of [11C]PLN was measured and used for correction of VT values. Distribution volume ratio (DVR) was calculated from VT of target and reference regions and obtained by noninvasive Logan graphical reference tissue model (LGAR) (t* = 30 min). Absolute test-retest variability (aTRV), and intra-class correlation coefficient (ICC) of VT and DVR were calculated as indexes of repeatability. Correlation between DVR and serum concentration of caffeine (a nonselective A2AR blocker) was analyzed by Pearson's correlation analysis. RESULTS: Regional time-activity curves were well described by 2-TCM models. Estimation of VT by 2-TCM produced some erroneous values; therefore, the more robust Logan plot was selected as the appropriate model. Global mean aTRV was 20% for VT and 14% for VT/fP (ICC, 0.72 for VT and 0.87 for VT/fP). Global mean aTRV of DVR was 13% for Logan plot and 10% for LGAR (ICC, 0.70 for Logan plot and 0.81 for LGAR). DVR estimates using LGAR and Logan plot were in good agreement (r2 = 0.96). Coefficients of variation for VT, VT/fP, DVR (Logan plot), and DVR (LGAR) were 47%, 47%, 27%, and 18%, respectively. Despite low serum caffeine levels, significant concentration-dependent effects on [11C]PLN binding to target regions were observed (p < 0.01). CONCLUSIONS: In this study, moderate test-retest reproducibility and large inter-subject differences were observed with [11C]PLN PET, possibly attributable to competition by baseline amount of caffeine. Analysis of plasma caffeine concentration is recommended during [11C]PLN PET studies. TRIAL REGISTRATION: UMIN000030040.

First clinical assessment of [18F]MC225, a novel fluorine-18 labelled PET tracer for measuring functional P-glycoprotein at the blood–brain barrier
Jun Toyohara; Muneyuki Sakata; Kenji Ishibashi; Pascalle Mossel; Masamichi Imai; Kei Wagatsuma; Tetsuro Tago; Etsuko Imabayashi; Nicola A. Colabufo; Gert Luurtsema; Kenji Ishii
Annals of Nuclear Medicine, 35, 11, 1240, 1252, Springer Science and Business Media LLC, Nov. 2021, [Peer-reviewed], [Domestic magazines]
English, Scientific journal, OBJECTIVE: 5-(1-(2-[18F]fluoroethoxy))-[3-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)-propyl]-5,6,7,8-tetrahydronaphthalen ([18F]MC225) is a selective substrate for P-glycoprotein (P-gp), possessing suitable properties for measuring overexpression of P-gp in the brain. This is the first-in-human study to examine safety, radiation dosimetry and P-gp function at the blood-brain barrier (BBB) of [18F]MC225 in healthy subjects. METHODS: [18F]MC225 biodistribution and dosimetry were determined in 3 healthy male subjects, using serial 2 h and intermittent 4 and 6 h whole-body PET scans acquired after [18F]MC225 injection. Dynamic [18F]MC225 brain PET (90 min) was obtained in 5 healthy male subjects. Arterial blood was sampled at various time intervals during scanning and the fraction of unchanged [18F]MC225 in plasma was determined. T1-weighted MRI was performed for anatomical coregistration. Total distribution volume (VT) was estimated using 1- and 2-tissue-compartment models (1-TCM and 2-TCM, respectively). VT was also estimated using the Logan graphical method (Logan plot) (t* = 20 min). Surrogate parameters without blood sampling (area-under the curve [AUC] of regional time-activity curves [TACs] and negative slope of calculated TACs) were compared with the VT values. RESULTS: No serious adverse events occurred throughout the study period. Although biodistribution implied hepatobiliary excretion, secretion of radioactivity from liver to small intestine through the gallbladder was very slow. Total renal excreted radioactivity recovered during 6 h after injection was < 2%ID. Absorbed dose was the highest in the pancreas (mean ± SD, 203 ± 45 μGy/MBq) followed by the liver (83 ± 11 μGy/MBq). Mean effective dose with and without urination was 17 ± 1 μSv/MBq. [18F]MC225 readily entered the brain, distributing homogeneously in grey matter regions. 2-TCM provided lower Akaike information criterion scores than did 1-TCM. VT estimated by Logan plot was well correlated with that of 2-TCM (r2 > 0.9). AUCs of TACs were positively correlated with VT (2-TCM) values (r2: AUC0-60 min = 0.61, AUC0-30 min = 0.62, AUC30-60 min = 0.59, p < 0.0001). Negative slope of SUV TACs was negatively correlated with VT (2-TCM) values (r2 = 0.53, p < 0.0001). CONCLUSIONS: This initial evaluation indicated that [18F]MC225 is a suitable and safe PET tracer for measuring P-gp function at the BBB.

Risk Communication of Radiation Exposure for Diagnosis: A Questionnaire Survey
大塚駿; 新井知大; 我妻慧; 我妻慧; 菅原康晴; 堀川大輔; 篠ヶ瀬知; 吉川宏起
日本放射線技術学会雑誌, 77, 7, 691, 699, Jul. 2021, [Peer-reviewed]
Japanese, Scientific journal

Brain 11 C-ITMM PET to longitudinally assess type 1 metabotropic glutamate receptor availability in Alzheimer's disease
Kenji Ishibashi; Yoshiharu Miura; Kei Wagatsuma; Masashi Kameyama; Kenji Ishii
Journal of Neuroimaging, 31, 5, 864, 868, Wiley, 18 Jun. 2021, [Peer-reviewed], [International Magazine]
English, Scientific journal, BACKGROUND AND PURPOSE: Little evidence exists on the role of type 1 metabotropic glutamate receptor (mGluR1) in the pathophysiology of Alzheimer's disease (AD), although mGluR1 may be involved in the regulation of neuronal excitability and synaptic plasticity. We have recently reported that mGluR1 availability in the early stage of AD is equivalent to that in healthy subjects. This study aimed to address whether mGluR1 availability changes with the progression of AD. METHODS: Eight patients with AD (79.1 ± 4.6 years) underwent a total of two positron emission tomography (PET) examinations using the mGluR1 radioligand during the early-to-middle stages of AD. The mean interval was 2.8 years. Volumes-of-interest were placed on the frontal, parietal, and temporal cortices, hippocampus, anterior and posterior lobes, and vermis in the cerebellum. The binding potential (BPND ) was calculated to estimate mGluR1 availability, applying partial volume correction to the BPND values. RESULTS: No significant difference was observed in BPND values between the first and second PET examinations in the frontal cortex (p = 0.94), parietal cortex (p = 0.67), temporal cortex (p = 0.20), hippocampus (p = 0.17), anterior lobe (p = 0.73), posterior lobe (p = 0.21), and vermis (p = 0.22). CONCLUSION: This study suggests that mGluR1 availability is unchanged in the follow-up period of a few years during the early-to-middle stages of AD.

Centiloid scale analysis for 18F-THK5351 PET imaging in Alzheimer’s disease
Tensho Yamao; Kenta Miwa; Kei Wagatsuma; Yoko Shigemoto; Noriko Sato; Go Akamatsu; Hiroshi Ito; Hiroshi Matsuda
Physica Medica, 82, 249, 254, Elsevier BV, Feb. 2021, [Peer-reviewed], [International Magazine]
English, Scientific journal, PURPOSE: A standardized method for quantification is required for analyzing PET data, but such standards have not been established for tau PET imaging. The Centiloid scale has recently been proposed as a standard method for quantifying amyloid deposition on PET imaging. Therefore, the present study aimed to apply the Centiloid scale to 18F-THK5351 PET imaging in Alzheimer's disease (AD). METHODS: We acquired 18F-THK5351 PET, 11C-PiB PET, and MR images from 47 cognitively normal (CN) individuals and 28 patients with AD with mild to moderate dementia. PET images were spatially normalized to Montreal Neurological Institute space. The PET signals were then normalized using the signal in the reference volume of interest (VOI). Target VOI for specific 18F-THK5351 retention in AD was extracted by voxel-wise comparison of PET images between the 47 CN individuals and 16 AD patients with moderate dementia. Scale anchor points were defined by the CN individuals as 0-anchor points and by that of the average of the typical AD patients as 100-anchor points. RESULTS: Specific retention of 18F-THK5351 was predominant in the angular gyrus, inferior temporal cortex, and parieto-occipital regions in patients with AD. Standardized uptake value ratio (SUVR) of 1.227 and 1.797 were defined as 0- and 100-anchor points, respectively. 18F-THK5351 PET data could be expressed using the Centiloid scale, with the SUVR of the 18F-THK5351 PET images converted to Centiloid using our VOI, the standard Centiloid reference VOI, and the following equation: Centiloid = 169.0 × SUVR-204.6. CONCLUSION: Centiloid methods can be applied to tau PET imaging using 18F-THK5351.

18F-florbetapirアミロイドPETイメージングの定量解析ソフトウェアの交差検証
我妻 慧; 三輪 建太; 坂田 宗之; 石橋 賢士; 石井 賢二
日本放射線技術学会雑誌, 77, 1, 32, 40, (公社)日本放射線技術学会, Jan. 2021, [Peer-reviewed], [Lead author, Corresponding author]
Japanese, Amygo neuroの解析結果を、臨床用の18F-florbetapir PET画像の定量解析ソフトウェアとしてすでに国内外で実績があるMIMneuroと比較して、Amygo neuroで計算されるstandardized uptake value ratio(SUVR)の精度を交差検証した。18F-florbetapirによるPET検査を施行した40名(健常者31名、アルツハイマー病疑い7名、進行性失語症2名)を対象とした。cSUVRを使用した判定において、Amygo neuroとMIMneuroともに40例中15例(37.5%)がcSUVR>1.10でAβ陽性であった。二つの解析ソフトウェアのrSUVRの相対誤差は±5%以内に収まっており、最終的なアミロイドPETの判定に使用されるcSUVRはAmygo neuroとMIMneuro間で有意差はなかった。Amygo neuroとMIMneuro間のrSUVRとcSUVRの相関係数について、すべてのSUVRが非常に良好な相関を示した。Amygo neuroは被験者のMRIを使用せずに全自動で解析ができ、解析結果のレポート出力も可能なことから診療利用が容易であると考えられた。

Direct comparison of brain [18F]FDG images acquired by SiPM-based and PMT-based PET/CT: phantom and clinical studies.
Kei Wagatsuma; Muneyuki Sakata; Kenji Ishibashi; Akira Hirayama; Hirofumi Kawakami; Kenta Miwa; Yukihisa Suzuki; Kenji Ishii
EJNMMI physics, 7, 1, 70, 70, 23 Nov. 2020, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
English, Scientific journal, BACKGROUND: Silicon photomultiplier-positron emission tomography (SiPM-PET) has better sensitivity, spatial resolution, and timing resolution than photomultiplier tube (PMT)-PET. The present study aimed to clarify the advantages of SiPM-PET in 18F-fluoro-2-deoxy-D-glucose ([18F]FDG) brain imaging in a head-to-head comparison with PMT-PET in phantom and clinical studies. METHODS: Contrast was calculated from images acquired from a Hoffman 3D brain phantom, and image noise and uniformity were calculated from images acquired from a pool phantom using SiPM- and PMT-PET. Sequential PMT-PET and SiPM-PET [18F]FDG images were acquired over a period of 10 min from 22 controls and 10 patients. All images were separately normalized to a standard [18F]FDG PET template, then the mean standardized uptake values (SUVmean) and Z-score were calculated using MIMneuro and CortexID Suite, respectively. RESULTS: Image contrast, image noise, and uniformity in SiPM-PET changed 19.2, 3.5, and - 40.0% from PMT-PET, respectively. These physical indices of both PET scanners satisfied the criteria for acceptable image quality published by the Japanese Society of Nuclear Medicine of contrast > 55%, CV ≤ 15%, and SD ≤ 0.0249, respectively. Contrast was 70.0% for SiPM-PET without TOF and 59.5% for PMT-PET without TOF. The TOF improved contrast by 3.5% in SiPM-PET. The SUVmean using SiPM-PET was significantly higher than PMT-PET and did not correlate with a time delay. Z-scores were also significantly higher in images acquired from SiPM-PET (except for the bilateral posterior cingulate) than PMT-PET because the peak signal that was extracted by the calculation of Z-score in CortexID Suite was increased. The hypometabolic area in statistical maps was reduced and localized using SiPM-PET. The trend was independent of whether the images were derived from controls or patients. CONCLUSIONS: The improved spatial resolution and sensitivity of SiPM-PET contributed to better image contrast and uniformity in brain [18F]FDG images. The SiPM-PET offers better quality and more accurate quantitation of brain PET images. The SUVmean and Z-scores were higher in SiPM-PET than PMT-PET due to improved PVE. [18F]FDG images acquired using SiPM-PET will help to improve diagnostic outcomes based on statistical image analysis because SiPM-PET would localize the distribution of glucose metabolism on Z-score maps.

Adenosine A2A Receptor Occupancy by Long-Term Istradefylline Administration in Parkinson's Disease.
Kenji Ishibashi; Yoshiharu Miura; Kei Wagatsuma; Jun Toyohara; Kiichi Ishiwata; Kenji Ishii
Movement disorders : official journal of the Movement Disorder Society, 36, 1, 268, 269, 16 Nov. 2020, [Peer-reviewed], [International Magazine]
English

Neural substrate of a cognitive intervention program using Go game: a positron emission tomography study.
Ai Iizuka; Kenji Ishii; Kei Wagatsuma; Kenji Ishibashi; Airin Onishi; Mika Tanaka; Hiroyuki Suzuki; Shuichi Awata; Yoshinori Fujiwara
Aging clinical and experimental research, 32, 11, 2349, 2355, Nov. 2020, [Peer-reviewed], [International Magazine]
English, Scientific journal, BACKGROUND: Influence of cognitive intervention programs on brain activity has not been enough explored. AIMS: The aims of the present study were to clarify changes in brain activity from a cognitive intervention program utilizing the board game "Go" and to examine the relationship between brain activity and the acquisition of Go skills. METHODS: Eighteen community-dwelling older adults were randomly assigned either to an intervention group (IG), in which members attended 12 Go lessons either in groups or individually using tablet computers, or a control group (CG), in which members attended health education lectures unrelated to Go. Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET), cognitive assessments, and Go tests were performed before and after the intervention. RESULTS: The results showed different patterns of regional FDG uptake in both groups: regional cerebral glucose metabolism was significantly increased in the left middle temporal gyrus (MTG) and bilateral putamen (p < 0.01; cluster level) in the IG, and in the left superior frontal gyrus in the CG, (p < 0.01; cluster level). Furthermore, Go test scores were significantly improved in the IG (p < 0.05), and a significant association was observed between changes in Go test scores and glucose metabolism in the left MTG (p < 0.05). CONCLUSIONS AND DISCUSSION: This study indicates that a cognitive intervention program using Go may enhance brain activity. Further studies with larger populations and longer observation periods are needed to clarify the neural mechanisms underlying our Go intervention program.

Voxel-based morphometry focusing on medial temporal lobe structures has a limited capability to detect amyloid β, an Alzheimer's disease pathology.
Masashi Kameyama; Kenji Ishibashi; Jun Toyohara; Kei Wagatsuma; Yumi Umeda-Kameyama; Keigo Shimoji; Kazutomi Kanemaru; Shigeo Murayama; Sumito Ogawa; Aya M Tokumaru; Kenji Ishii
Aging, 12, 19, 19701, 19710, 05 Oct. 2020, [Peer-reviewed], [International Magazine]
English, Scientific journal, Voxel-based morphometry (VBM) analysis of nuclear Magnetic Resonance Imaging (MRI) data allows the identification of medial temporal lobe (MTL) atrophy and is widely used to assist the diagnosis of Alzheimer's disease (AD). However, its reliability in the clinical environment has not yet been confirmed. To determine the credibility of VBM, amyloid positron emission tomography (PET) and VBM studies were compared retrospectively. Patients who underwent Pittsburgh Compound B (PiB) PET were retrospectively recruited. Ninety-seven patients were found to be amyloid negative and 116 were amyloid positive. MTL atrophy in the PiB positive group, as quantified by thin sliced 3D MRI and VBM software, was significantly more severe (p =0.0039) than in the PiB negative group. However, data histogram showed a vast overlap between the two groups. The area under the ROC curve (AUC) was 0.646. MMSE scores of patients in the amyloid negative and positive groups were also significantly different (p = 0.0028), and the AUC was 0.672. Thus, MTL atrophy could not reliably differentiate between amyloid positive and negative patients in a clinical setting, possibly due to the wide array of dementia-type diseases that exist other than AD.

Detection of sub-centimeter lesions using digital TOF-PET/CT system combined with Bayesian penalized likelihood reconstruction algorithm.
Kenta Miwa; Kei Wagatsuma; Reo Nemoto; Masaki Masubuchi; Yuto Kamitaka; Tensho Yamao; Seiya Hiratsuka; Masashi Yamaguchi; Tokiya Yoshii; Rinya Kobayashi; Noriaki Miyaji; Kenji Ishii
Annals of nuclear medicine, 34, 10, 762, 771, Oct. 2020, [Peer-reviewed], [Domestic magazines]
English, Scientific journal, OBJECTIVE: Many advances in PET/CT technology can potentially improve image quality and the ability to detect small lesions. A new digital TOF-PET/CT scanner based on silicon photomultipliers (SiPM) integrated with a Bayesian penalized likelihood (BPL) PET reconstruction algorithm (Q.Clear; GE Healthcare) has been introduced into clinical practice. The present study aimed to quantify the ability of a digital TOF-PET/CT scanner combined with BPL reconstruction to detect small lesions, and to determine the optimal penalization factor (β) in BPL to accurately detect such lesions. METHODS: All PET data were acquired from a NEMA body phantom using a Discovery MI (DMI) PET/CT system (GE Healthcare). The phantom included six spheres with diameters of 4, 5, 6, 8, 10, and 13 mm, and contained a background activity level of 5.3 kBq/mL, with target-to-background ratios (TBR) of 4:1 and 8:1. Images were reconstructed using a baseline OSEM algorithm, with OSEM + PSF, OSEM + TOF, OSEM + PSF + TOF, and BPL + PSF + TOF (β: 50-400). The matrix size was 192 × 192 and 384 × 384. Data acquired in 100-min list mode were re-binned into acquisition times ranging from 2 to 100 min. The quantitative accuracy and detectability of small hot spheres were evaluated by physical assessment of a recovery coefficient (RC) and a detectability index (DI), as well as visual assessment of PET images at each acquisition time. RESULTS: The RC and DI of sub-centimeter spheres were improved, because the digital TOF-PET/CT scanner has a larger TOF performance gain due to better timing resolution. The RC and DI were higher with BPL in sub-centimeter spheres, than with other OSEM-based types of reconstruction. The BPL for an 8-mm sphere overestimated uptake due to edge artifact overshoot induced by PSF modeling. The variability of RC and DI for acquisition times and TBR differed considerably according to β values. The RC for ~ 8-mm spheres were > 1 at β values between 50 and 100, but were close to 1 at β value of 200. The visual scores for β = 200 in BPL were maximal, whereas those for spheres that were ≥ 6 mm exceeded the criterion of 3. CONCLUSION: The BPL in the digital TOF-PET/CT scanner improved the quantitation and detectability of sub-centimeter spheres compared with OSEM-based reconstruction. Optimization of the β value in BPL might allow the detection of lesions ≤ 6 mm, although detectability depended on the TBR of lesions. A β value of 200 seemed optimal for detecting sub-centimeter lesions.

Optimization of a Bayesian penalized likelihood algorithm (Q.Clear) for 18F-NaF bone PET/CT images acquired over shorter durations using a custom-designed phantom.
Tokiya Yoshii; Kenta Miwa; Masashi Yamaguchi; Kai Shimada; Kei Wagatsuma; Tensho Yamao; Yuto Kamitaka; Seiya Hiratsuka; Rinya Kobayashi; Hajime Ichikawa; Noriaki Miyaji; Tsuyoshi Miyazaki; Kenji Ishii
EJNMMI physics, 7, 1, 56, 56, 11 Sep. 2020, [Peer-reviewed], [International Magazine]
English, Scientific journal, BACKGROUND: The Bayesian penalized likelihood (BPL) algorithm Q.Clear (GE Healthcare) allows fully convergent iterative reconstruction that results in better image quality and quantitative accuracy, while limiting image noise. The present study aimed to optimize BPL reconstruction parameters for 18F-NaF PET/CT images and to determine the feasibility of 18F-NaF PET/CT image acquisition over shorter durations in clinical practice. METHODS: A custom-designed thoracic spine phantom consisting of several inserts, soft tissue, normal spine, and metastatic bone tumor, was scanned using a Discovery MI PET/CT scanner (GE Healthcare). The phantom allows optional adjustment of activity distribution, tumor size, and attenuation. We reconstructed PET images using OSEM + PSF + TOF (2 iterations, 17 subsets, and a 4-mm Gaussian filter), BPL + TOF (β = 200 to 700), and scan durations of 30-120 s. Signal-to-noise ratios (SNR), contrast, and coefficients of variance (CV) as image quality indicators were calculated, whereas the quantitative measures were recovery coefficients (RC) and RC linearity over a range of activity. We retrospectively analyzed images from five persons without bone metastases (male, n = 1; female, n = 4), then standardized uptake values (SUV), CV, and SNR at the 4th, 5th, and 6th thoracic vertebra were calculated in BPL + TOF (β = 400) images. RESULTS: The optimal reconstruction parameter of the BPL was β = 400 when images were acquired at 120 s/bed. At 90 s/bed, the BPL with a β value of 400 yielded 24% and 18% higher SNR and contrast, respectively, than OSEM (2 iterations; 120 s acquisitions). The BPL was superior to OSEM in terms of RC and the RC linearity over a range of activity, regardless of scan duration. The SUVmax were lower in BPL, than in OSEM. The CV and vertebral SNR in BPL were superior to those in OSEM. CONCLUSIONS: The optimal reconstruction parameters of 18F-NaF PET/CT images acquired over different durations were determined. The BPL can reduce PET acquisition to 90 s/bed in 18F-NaF PET/CT imaging. Our results suggest that BPL (β = 400) on SiPM-based TOF PET/CT scanner maintained high image quality and quantitative accuracy even for shorter acquisition durations.

18F-sodium fluoride positron emission tomography may help determine better treatment for thigh pain after hip arthroplasty-A case report.
Shinya Nakamura; Shigehito Uezono; Yuko Nagai; Masakazu Kanetaka; Kei Wagatsuma; Kenji Ishii; Takeshi Kumakawa; Kensuke Yasue; Yorito Anamizu; Fumiaki Tokimura; Tsuyoshi Miyazaki
Clinical case reports, 8, 9, 1651, 1658, Sep. 2020, [Peer-reviewed], [International Magazine]
English, Thigh pain after hip arthroplasty is multifactorial; uncovering its etiology is paramount for optimal treatment. This is the first case where 18F-sodium fluoride positron emission tomography substantially helped in diagnosing the post-hip arthroplasty persistent thigh pain and appropriate treatment selection. This imaging modality warrants further study and more widespread application.

Longitudinal 18F-FDG Images in Patients With Alzheimer Disease Over More Than 9 Years From a Preclinical Stage.
Kenji Ishibashi; Airin Onishi; Kei Wagatsuma; Yoshinori Fujiwara; Kenji Ishii
Clinical nuclear medicine, 45, 4, e185-e189, Apr. 2020, [Peer-reviewed], [International Magazine]
English, Scientific journal, BACKGROUND: Brain F-FDG uptake reportedly starts to decline more than 10 years before the onset of cognitive decline in dominantly inherited Alzheimer disease (AD). We compared longitudinal F-FDG images in sporadic AD to aging data from a large sample size to expand the current knowledge of F-FDG reduction for AD progression. METHODS: Participants comprised 2 individuals (subjects A and B at ages 65 and 68 years, respectively) and 107 control subjects (67.9 [SD, 4.9] years). Subject A underwent F-FDG PET a total of 8 times over 9 years from the preclinical to early dementia stages. Subject B underwent F-FDG PET a total of 11 times over 12 years from the preclinical to mild cognitive impairment stages. Control subjects underwent F-FDG PET twice over a mean follow-up period of 7.8 years. After placing the volume of interest on the AD-related hypometabolic regions, the longitudinal F-FDG images were compared among the subjects and control subjects. RESULTS: For the control group, the rate of F-FDG reduction was 2.2% per decade (ie, aging effects). The rates of F-FDG reduction were 9.41% over 9 years and 9.07% over 12 years in subjects A and B, respectively. We estimated that F-FDG uptake started to decrease 4 and 2 years before indications of memory loss in subjects A and B, respectively. CONCLUSIONS: The present study suggests that the time between the beginning of F-FDG reduction and the onset of cognitive decline may be shorter in elderly individuals with AD compared with the recently estimated period in dominantly inherited AD.

Metabolic Network Topology of Alzheimer's Disease and Dementia with Lewy Bodies Generated Using Fluorodeoxyglucose Positron Emission Tomography.
Masamichi Imai; Mika Tanaka; Muneyuki Sakata; Kei Wagatsuma; Tetsuro Tago; Jun Toyohara; Renpei Sengoku; Yuji Nishina; Kazutomi Kanemaru; Kenji Ishibashi; Shigeo Murayama; Kenji Ishii
Journal of Alzheimer's disease : JAD, 73, 1, 197, 207, Jan. 2020, [Peer-reviewed], [International Magazine]
English, Scientific journal, BACKGROUND: Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) are often misdiagnosed with each other because of similar symptoms including progressive memory loss. The metabolic network topology that describes inter-regional metabolic connections can be generated using fluorodeoxyglucose positron emission tomography (FDG-PET) data with the graph-theoretical method. We hypothesized that different metabolic connectivity underlies the symptoms of AD patients, DLB patients, and cognitively normal (CN) individuals. OBJECTIVE: This study aimed to generate metabolic connectivity using FDG-PET data and assess the network topology to differentiate AD patients, DLB patients, and CN individuals. METHODS: This study included 45 AD patients, 18 DLB patients, and 142 CN controls. We analyzed FDG-PET data using the graph-theoretical method and generated the network topology in AD patients, DLB patients, and CN individuals. We statistically assessed the topology with global and nodal parameters. RESULTS: The whole metabolic network was preserved in CN; however, diffusely decreased connection was found in AD and partially but more deeply decreased connection was observed in DLB. The metabolic topology revealed that the right posterior cingulate and the left transverse temporal gyrus were significantly different between AD and DLB. CONCLUSION: The present findings indicate that metabolic connectivity decreased in both AD and DLB, compared with CN. DLB was characterized restricted but deeper stereotyped network disruption compared with AD. The right posterior cingulate and the left transverse temporal gyrus are significant regions in the metabolic connectivity for differentiating AD from DLB.

A pitfall of white matter reference regions used in [18F] florbetapir PET: a consideration of kinetics.
Masashi Kameyama; Kenji Ishibash; Kei Wagatsuma; Jun Toyohara; Kenji Ishii
Annals of nuclear medicine, 33, 11, 848, 854, Nov. 2019, [Peer-reviewed], [Domestic magazines]
English, Scientific journal, OBJECTIVE: Many studies have demonstrated the superiority of white matter (WM) reference regions (RR) in amyloid PET studies in comparison to cerebellar RR. However, the principle behind its improved measurement stability is yet to be elucidated. Our study aimed to determine the origin of WM stability; stability over cerebral blood flow and input function fluctuation or the greater statistical noise in the cerebellum due to its smaller size and its location in the axial periphery of the PET scanner bore. METHODS: We conducted simulations of [[Formula: see text]F] florbetapir using in-house program varying [Formula: see text] and input function, and adding statistical noise. RESULTS: Our simulations revealed that WM RR were more susceptible to CBF variation and input function fluctuation than cerebellar RR. WM RR did not gave superior measurement stability unless cerebellar statistical noise exceeded 4.55 times that in WM, a figure often surpassed in traditional amyloid PET studies. The greater statistical noise in cerebellum is likely the etiology for improved measurement stability of WM RR. CONCLUSION: A longitudinal [[Formula: see text]F] florbetapir PET study should be conducted with a long bore PET. It can also be hypothesized that a second scan with the cerebellum in the axial center of a 3D PET, using a cerebellar RR to calculate changes in tracer concentration may improve the measurement stability of longitudinal [[Formula: see text]F] florbetapir studies.

NaF PET assessment of bone metabolic changes around the femoral canal by intramedullary femoral alignment technique in total knee arthroplasty.
Soichiro Kaneko; Masakazu Kanetaka; Kei Wagatsuma; Kenji Ishii; Yorito Anamizu; Fumiaki Tokimura; Tsuyoshi Miyazaki
Clinical case reports, 7, 6, 1211, 1214, Jun. 2019, [Peer-reviewed], [International Magazine]
English, We used the NaF PET scan to assess osteometabolic changes around the distal half of the femoral canal by intramedullary (IM) drill for femoral IM guiding rod insertion in total knee arthroplasty. Gentle IM rod insertion and focused attention can minimize surgical stress-induced biological reaction of the femoral IM canal.

Pre-discard estimation of radioactivated materials in positron emission tomography cyclotron systems and concrete walls of a cyclotron vault.
Kei Wagatsuma; Kiichi Ishiwata; Fumiyoshi Nobuhara; Iwane Koumura; Masayuki Kunugi; Keiichi Oda; Kenta Miwa; Jun Toyohara; Kenji Ishii
Medical physics, 46, 5, 2457, 2467, May 2019, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
English, Scientific journal, PURPOSE: The concrete vault, cyclotron body, and peripheral equipment in a cyclotron room become radioactivated by neutrons generated by operating an unshielded cyclotron. Radionuclides and the amounts of radioactivated materials must be identified before discarding a cyclotron system. The present study aimed to reduce the amounts of concrete from cyclotron vaults, as well as cyclotron components and peripheral equipment, that will be disposed of as radioactivated waste by clarifying the nature and quantity of radioactivated materials remaining in facilities after cyclotron operations have ceased. METHODS: Cylindrical concrete cores were bored into all four walls, ceiling, and floor of a room where a Cypris 370 cyclotron had been operated for 22.8 yr and then cooled for 40 months. The accelerated particles comprised protons and deuterons with constant energy of 18 and 10 MeV, respectively. The types and amounts of radionuclides in these cores, in 38 components of the cyclotron including the yoke, and in 13 pieces of equipment in the room, were determined by γ-ray spectrometry. Concentrations of radioactivity were also calculated using an updated version of Particle and Heavy Ion Transport System and DCHAIN-SP. Amounts of materials with both measured and calculated total radioactivity concentration (ΣD) of <0.1 Bq/g were identified as being nonradioactivated. RESULTS: The major radionuclides in the concrete were 60 Co and 152 Eu. The radioactivated concrete was distributed to a depth of <38 cm. Most cyclotron components and equipment were radioactivated by neutrons. The major radionuclides in cyclotron components and equipment were 54 Mn, 60 Co, and 65 Zn. A 33% volume of the yoke was regarded as nonradioactivated. CONCLUSIONS: The estimated amount of radioactivated waste in the concrete was about 70,000 kg (12.5% of the total concrete). Most components of the cyclotron except for the 33% volume of the yoke (20% of the cyclotron body), as well as most peripheral equipment in the room, were radioactivated. Part-by-part assessments of radioactive materials using measurements and calculations could distinguish nonradioactive from radioactive materials before they are discarded.

Occupancy of adenosine A2A receptors by istradefylline in patients with Parkinson's disease using 11C-preladenant PET.
Kenji Ishibashi; Yoshiharu Miura; Kei Wagatsuma; Jun Toyohara; Kiichi Ishiwata; Kenji Ishii
Neuropharmacology, 143, 106, 112, Dec. 2018, [Peer-reviewed], [International Magazine]
English, Scientific journal, Istradefylline, an adenosine A2A receptor (A2AR) antagonist, is effective as an adjunct to levodopa and can alleviate "off" time and motor symptoms in patients with Parkinson's disease (PD). The present study aimed to calculate occupancy rates of A2ARs by administrating istradefylline 20 mg or 40 mg, which is the currently approved dose for PD in Japan. Additionally, A2AR availability was compared between patients with PD and healthy controls. Ten patients with PD under levodopa therapy and six age-matched healthy controls were included. The patients underwent a total of two 11C-preladenant positron emission tomography scans before and after the administration of istradefylline 20 mg or 40 mg (both n = 5). Binding potential (BPND) was calculated to estimate A2AR availability in the ventral striatum, caudate, and putamen. Maximal A2AR occupancy and ED50 were estimated by modeling the dose-occupancy curves. All patients were around the middle stage of PD, and their characteristics were clinically heterogeneous. Maximal A2AR occupancy and ED50 were 93.5% and 28.6 mg in the ventral striatum, 69.5% and 10.8 mg in the caudate, and 66.8% and 14.8 mg in the putamen, respectively. There were no significant differences in BPND values in the ventral striatum (P = 0.42), caudate (P = 0.72), and putamen (P = 0.43) between the PD and control groups. In conclusion, the present study shows that istradefylline binds to A2ARs dose-dependently. A sufficient occupancy of A2ARs could be obtained by administrating the approved dose of istradefylline.

Validation of scatter limitation correction to eliminate scatter correction error in oxygen-15 gas-inhalation positron emission tomography images.
Kei Wagatsuma; Keiichi Oda; Muneyuki Sakata; Motoki Inaji; Kenta Miwa; Masayuki Sasaki; Jun Toyohara; Kenji Ishii
Nuclear medicine communications, 39, 10, 936, 944, Oct. 2018, [Peer-reviewed], [Lead author], [International Magazine]
English, Scientific journal, OBJECTIVE: High levels of radioactivity inside a facemask cause scatter correction (SC) errors that appear as photopenic artifacts on quantitative oxygen-15 (O) gas-inhalation positron emission tomography (PET) images. The present study aimed to validate the ability of scatter limitation correction (SLC) to eliminate SC errors in O gas-inhalation PET images acquired from patients and a phantom. MATERIALS AND METHODS: We analyzed the SC errors in phantom images and calculated parametric images of the cerebral blood flow (CBF), cerebral blood volume, oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2). Phantoms comprised a cylinder and paper with radioactivity to simulate a facemask during (O)O2 gas inhalation. Parametric images were calculated from O gas-inhalation PET images of ten participants. All PET data were reconstructed using conventional SC as model-based SC and SLC. Images acquired from the phantoms and parametric images were assessed visually and quantitatively in the presence and absence of SC error. RESULTS: SC error was evident in images derived from the paper phantom and at the slice level of the cerebellum in CBF, OEF, and CMRO2 images. The radioactivity concentration in the cylindrical phantom with the paper phantom significantly improved with SLC. The SLC also increased the quantitative indices of CBF, OEF, and CMRO2 by 23.8, 42.2, and 44.4%, respectively. CONCLUSION: SLC visually eliminated the SC error and increased the quantitative parameters on O gas-inhalation images derived from a phantom and from patients.

Unique Angiographic Appearances of Moyamoya Disease Detected with 3-Dimensional Rotational Digital Subtraction Angiography Imaging Showing the Hemodynamic Status.
Jun Karakama; Tadashi Nariai; Shoko Hara; Shihori Hayashi; Kazutaka Sumita; Motoki Inaji; Yoji Tanaka; Kei Wagatsuma; Kenji Ishii; Shigeru Nemoto; Taketoshi Maehara
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association, 27, 8, 2147, 2157, W.B. Saunders, Aug. 2018, [Peer-reviewed], [International Magazine]
English, Scientific journal

Multicenter study of quantitative PET system harmonization using NIST-traceable 68Ge/68Ga cross-calibration kit.
Kenta Miwa; Kei Wagatsuma; Takashi Iimori; Koichi Sawada; Takashi Kamiya; Minoru Sakurai; Noriaki Miyaji; Taisuke Murata; Eisuke Sato
Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB), 52, 98, 103, Aug. 2018, [Peer-reviewed], [Lead author], [International Magazine]
English, Scientific journal, PURPOSE: The present study aimed to define the errors in SUV and demonstrate the feasibility of SUV harmonization among contemporary PET/CT scanners using a novel National Institute of Standards and Technology (NIST)-traceable 68Ge/68Ga source as the reference standard. METHODS: We used 68Ge/68Ga dose calibrator and PET sources made with same batch of 68Ge/68Ga embedded in epoxy that is traceable to the NIST standard. Bias in the amount of radioactivity and the radioactive concentrations measured by the dose calibrators and PET/CT scanners, respectively, was determined at five Japanese sites. We adjusted optimal dial setting of the dose calibrators and PET reconstruction parameters to close the actual amount of radioactivity and the radioactive concentration, respectively, of the NIST-traceable 68Ge/68Ga sources to harmonize SUV. Errors in SUV before and after harmonization were then calculated at each site. RESULTS: The average bias in the amount of radioactivity and the radioactive concentrations measured by dose calibrator and PET scanner was -4.94% and -12.22%, respectively, before, and -0.14% and -4.81%, respectively, after harmonization. Corresponding averaged errors in SUV measured under clinical conditions were underestimated by 7.66%, but improved by -4.70% under optimal conditions. CONCLUSION: Our proposed method using an NIST-traceable 68Ge/68Ga source identified bias in values obtained using dose calibrators and PET scanners, and reduced SUV variability to within 5% across different models of PET scanners at five sites. Our protocol using a standard source has considerable potential for harmonizing the SUV when contemporary PET scanners are involved in multicenter studies.

Bayesian penalized-likelihood reconstruction algorithm suppresses edge artifacts in PET reconstruction based on point-spread-function.
Shotaro Yamaguchi; Kei Wagatsuma; Kenta Miwa; Kenji Ishii; Kazumasa Inoue; Masahiro Fukushi
Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB), 47, 73, 79, Mar. 2018, [Peer-reviewed], [International Magazine]
English, Scientific journal, PURPOSE: The Bayesian penalized-likelihood reconstruction algorithm (BPL), Q.Clear, uses relative difference penalty as a regularization function to control image noise and the degree of edge-preservation in PET images. The present study aimed to determine the effects of suppression on edge artifacts due to point-spread-function (PSF) correction using a Q.Clear. METHODS: Spheres of a cylindrical phantom contained a background of 5.3 kBq/mL of [18F]FDG and sphere-to-background ratios (SBR) of 16, 8, 4 and 2. The background also contained water and spheres containing 21.2 kBq/mL of [18F]FDG as non-background. All data were acquired using a Discovery PET/CT 710 and were reconstructed using three-dimensional ordered-subset expectation maximization with time-of-flight (TOF) and PSF correction (3D-OSEM), and Q.Clear with TOF (BPL). We investigated β-values of 200-800 using BPL. The PET images were analyzed using visual assessment and profile curves, edge variability and contrast recovery coefficients were measured. RESULTS: The 38- and 27-mm spheres were surrounded by higher radioactivity concentration when reconstructed with 3D-OSEM as opposed to BPL, which suppressed edge artifacts. Images of 10-mm spheres had sharper overshoot at high SBR and non-background when reconstructed with BPL. Although contrast recovery coefficients of 10-mm spheres in BPL decreased as a function of increasing β, higher penalty parameter decreased the overshoot. CONCLUSIONS: BPL is a feasible method for the suppression of edge artifacts of PSF correction, although this depends on SBR and sphere size. Overshoot associated with BPL caused overestimation in small spheres at high SBR. Higher penalty parameter in BPL can suppress overshoot more effectively.

Response of Cerebral Blood Flow and Blood Pressure to Dynamic Exercise: A Study Using PET.
Mikio Hiura; Tadashi Nariai; Muneyuki Sakata; Akitaka Muta; Kenji Ishibashi; Kei Wagatsuma; Tetsuro Tago; Jun Toyohara; Kenji Ishii; Taketoshi Maehara
International journal of sports medicine, 39, 3, 181, 188, Georg Thieme Verlag, Feb. 2018, [Peer-reviewed], [International Magazine]
English, Scientific journal

Natural Postoperative Bone Metabolic Changes after Total Knee Arthroplasty Determined by Positron Emission Tomography Scans
Masakazu Kanetaka; Soichiro Kaneko; Kei Wagatsuma; Kenji Ishii; Kimiteru Ito; Shinya Nakamura; Hiroshi Hamaji; Yukimasa Yamato; Yorito Anamizu; Fumiaki Tokimura; Tsuyoshi Miyazaki
Open Journal of Orthopedics, 08, 12, 443, 457, Scientific Research Publishing, Inc., 2018, [Peer-reviewed]
English, Scientific journal

Dynamic Exercise Elicits Dissociated Changes Between Tissue Oxygenation and Cerebral Blood Flow in the Prefrontal Cortex: A Study Using NIRS and PET.
Mikio Hiura; Tadashi Nariai; Katsumi Takahashi; Akitaka Muta; Muneyuki Sakata; Kenji Ishibashi; Jun Toyohara; Kei Wagatsuma; Tetsuro Tago; Kenji Ishii; Taketoshi Maehara
Advances in experimental medicine and biology, 1072, 269, 274, 2018, [Peer-reviewed], [International Magazine]
English, Scientific journal, Neuronal activity causes changes in both cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow (CBF). Since the relationship between tissue oxygenation and regional CBF (rCBF) during exercise has not been elucidated, we compared the data obtained using near-infrared spectroscopy (NIRS) and rCBF examined using positron emission tomography (PET). Participants in this study comprised 26 healthy young men. Changes in concentration of oxygenated hemoglobin (ΔO2Hb) and deoxygenated hemoglobin (ΔHHb) in the prefrontal cortex (PFC) were measured using NIRS continuously during a 15-min bout of the constant-load low-intensity cycling exercise (n = 14). Under the same protocol as the NIRS study, rCBF was measured using H215O and PET by the autoradiographic method at baseline (Rest) and at 3 min (Ex1) and 13 min (Ex2) after starting exercise (n = 12). As systematic factors influenced by exercise, heart rate, end-tidal pressure of carbon dioxide (PETCO2) and blood pressure (BP) were monitored. For each region investigated by NIRS, rCBF was analyzed quantitatively using PET-MRI co-registered standardized images. Despite inter-individual differences, changing patterns of ΔO2Hb and ΔHHb in the PFC were similar between channels. Significant main effects for time point were identified in ΔO2Hb, ΔHHb and changes in rCBF. While rCBF increased from rest, ΔO2Hb was not changed at Ex1. Conversely, rCBF was unchanged from rest but ΔO2Hb was significantly increased at Ex2. Fluctuations of PETCO2 and BP evoked by exercise were not in accordance with changes in ΔO2Hb, ΔHHb and rCBF, while BP may affect the forehead skin blood flow. Given that NIRS data are a mixture of skin and brain effects, our results suggest that CMRO2 may differ between the phases in a bout of dynamic exercise. The present study indicates the utility of NIRS to examine the relationship between CMRO2 and rCBF during exercise.

O-labeled gas. The image quality with the neck shield was similar to that without the neck shield.
Kei Wagatsuma; Keiichi Oda; Kenta Miwa; Motoki Inaji; Muneyuki Sakata; Jun Toyohara; Kiichi Ishiwata; Masayuki Sasaki; Kenji Ishii
Radiol Phys Technol, 10, 4, 422, 430, Dec. 2017, [Peer-reviewed]
English

Revision with Locking Plate and Sliding Inlay Bone Graft for Hypertrophic Nonunion after Combined Treatment of Ender Nails and Teriparatide for Atypical Femoral Stress Fracture A Unique Case Report.
Koshiishi A; Hamaji H; Wada Y; Ito K; Wagatsuma K; Ishii K; Kanetaka M; Kaneko S; Uezono S; Shoda N; Anamizu Y; Tokimura F; Miyazaki T
J Orthopedics Rheumatol, 4, 2, 1, 6, Dec. 2017, [Peer-reviewed]
English

Assessment of safety, efficacy, and dosimetry of a novel 18-kDa translocator protein ligand, [11C]CB184, in healthy human volunteers.
Muneyuki Sakata; Kenji Ishibashi; Masamichi Imai; Kei Wagatsuma; Kenji Ishii; Kentaro Hatano; Kiichi Ishiwata; Jun Toyohara
EJNMMI research, 7, 1, 26, 26, Dec. 2017, [Peer-reviewed], [International Magazine]
English, Scientific journal

Effects of a novel tungsten-impregnated rubber neck shield on the quality of cerebral images acquired using 15O-labeled gas.
Kei Wagatsuma; Keiichi Oda; Kenta Miwa; Motoki Inaji; Muneyuki Sakata; Jun Toyohara; Kiichi Ishiwata; Masayuki Sasaki; Kenji Ishii
Radiological physics and technology, 10, 4, 422, 430, Springer Tokyo, Dec. 2017, [Peer-reviewed], [Lead author], [Domestic magazines]
English, Scientific journal

Optimization of a shorter variable-acquisition time for legs to achieve true whole-body PET/CT images.
Takuro Umeda; Kenta Miwa; Taisuke Murata; Noriaki Miyaji; Kei Wagatsuma; Kazuki Motegi; Takashi Terauchi; Mitsuru Koizumi
Australasian physical & engineering sciences in medicine, 40, 4, 861, 868, Dec. 2017, [Peer-reviewed], [International Magazine]
English, Scientific journal

Changes in brain amyloid-β accumulation after donepezil administration.
Kenji Ishibashi; Yoshiharu Miura; Kei Wagatsuma; Kiichi Ishiwata; Kenji Ishii
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 45, 328, 329, Nov. 2017, [Peer-reviewed], [International Magazine]
English, Scientific journal

Comparison between new-generation SiPM-based and conventional PMT-based TOF-PET/CT.
Kei Wagatsuma; Kenta Miwa; Muneyuki Sakata; Keiichi Oda; Haruka Ono; Masashi Kameyama; Jun Toyohara; Kenji Ishii
Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB), 42, 203, 210, Oct. 2017, [Peer-reviewed], [Lead author], [International Magazine]
English, Scientific journal

Initial Evaluation of an Adenosine A2A Receptor Ligand, 11C-Preladenant, in Healthy Human Subjects.
Muneyuki Sakata; Kenji Ishibashi; Masamichi Imai; Kei Wagatsuma; Kenji Ishii; Xiaoyun Zhou; Erik F J de Vries; Philip H Elsinga; Kiichi Ishiwata; Jun Toyohara
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 58, 9, 1464, 1470, Sep. 2017, [Peer-reviewed], [International Magazine]
English, Scientific journal

Age and gender effects of 11C-ITMM binding to metabotropic glutamate receptor type 1 in healthy human participants.
Muneyuki Sakata; Jun Toyohara; Kenji Ishibashi; Kei Wagatsuma; Kenji Ishii; Ming-Rong Zhang; Kiichi Ishiwata
Neurobiology of aging, 55, 72, 77, Jul. 2017, [Peer-reviewed], [International Magazine]
English, Scientific journal

Comparison of 3 Devices for Automated Infusion of Positron-Emitting Radiotracers.
Noriaki Miyaji; Kenta Miwa; Kei Wagatsuma; Taisuke Murata; Takuro Umeda; Takashi Terauchi; Mitsuru Koizumi
Journal of nuclear medicine technology, 45, 2, 91, 95, Society of Nuclear Medicine Inc., Jun. 2017, [Peer-reviewed], [International Magazine]
English, Scientific journal

Suppression of edge artifacts using a Bayesian penalized-likelihood reconstruction algorithm for oncological PET/CT imaging
Yamaguchi Shotaro; Wagatsuma Kei; Miwa Kenta; Ishii Kenji; Inoue Kazumasa; Fukushi Masahiro
JOURNAL OF NUCLEAR MEDICINE, 58, 01 May 2017, [Peer-reviewed]

Validation of Cross-calibration Schemes for Quantitative Bone SPECT/CT Using Different Sources under Various Geometric Conditions
宮司典明; 三輪建太; 茂木一樹; 梅田拓朗; 我妻慧; 深井翔平; 滝口智洋; 寺内隆司; 小泉満
日本放射線技術学会雑誌, 73, 6, 443, 450, 2017, [Peer-reviewed], [Domestic magazines]
Japanese, PURPOSE: Several cross-calibration schemes have been proposed to produce quantitative values in bone SPECT imaging. Differences in the radionuclide sources and geometric conditions can decrease the accuracy of cross-calibration factor (CCF). The present study aimed to validate the effects of calibration schemes using different sources under various geometric conditions. METHODS: Temporal variations as well as variations in acquisition counts and the shapes of 57Co standard and 99mTc point sources and a 99mTc disk source were determined. The effects of the geometric conditions of the source-to-camera distance (SCD) and lateral distance on the CCF were investigated by moving the camera or source away from the origin. The system planar sensitivity of NEMA incorporated into a Symbia Intevo SPECT/CT device (Siemens®) was defined as reference values. RESULTS: The temporal variation in CCF using the 57Co source was relatively stable within the range of 0.7% to 2.3%, whereas the 99mTc source ranged from 2.7% to 7.3%. In terms of source shape, the 57Co standard point source was the most stable. Both SCD and lateral distance decreased as a function of distance from the origin. Errors in the geometric condition were higher for the 57Co standard point source than the 99mTc disk source. CONCLUSIONS: Different calibration schemes influenced the reliability of quantitative values. The 57Co standard point source was stable over a long period, and this helped to maintain the quality of quantitative SPECT/CT imaging data. The CCF accuracy of the 99mTc source decreased depending on the preparative method. The method of calibration for quantitative SPECT should be immediately standardized to eliminate uncertainty.

Calculation Accuracy of Gross Tumor Volume at the Diaphragm Boundary Evaluated Using Respiratory-gated PET/CT
中澤脩人; 中澤脩人; 梅田拓朗; 宮司典明; 三輪建太; 我妻慧; 茂木一樹; 滝口智洋; 寺内隆司; 小泉満; 臼井桂介; 笹井啓資
日本放射線技術学会雑誌, 73, 8, 617, 625, 2017, [Peer-reviewed], [Domestic magazines]
Japanese, OBJECTIVE: The present study aimed to clarify gross tumor volume (GTV) contouring accuracy at the diaphragm boundary using respiratory-gated PET/CT. METHODS: The lung/diaphragm boundary was simulated using a phantom containing 18F solution (10.6 kBq/mL). Tumors were simulated using spheres (diameter, 11-38 mm) containing 18F and located at the positions of the lungs and liver. The tumor background ratios (TBR) were 2, 4, and 8. The phantom was moved from the superior to inferior direction with a 20-mm motion displacement at 3.6 s intervals. The recovery coefficient (RC), volume RC (VRC), and standardized uptake value (SUV) threshold were calculated using stationary, non-gated (3D), and gated (4D) PET/CT. RESULTS: In lung cancer simulation, RC and VRC in 3D PET images were, respectively, underestimated and overestimated in smaller tumors, whereas both improved in 4D PET images regardless of tumor size and TBR. The optimal SUV threshold was about 30% in 4D PET images. In liver cancer simulation, RC and VRC were, respectively, underestimated and overestimated in smaller tumors, and when the TBR was lower, but both improved in 4D PET images when tumors were >17 mm and the TBR was >4. The optimal SUV threshold tended to depend on the TBR. CONCLUSIONS: The contouring accuracy of GTV was improved by considering TBR and using an optimal SUV threshold acquired from 4D PET images.

A Comparison of Planar Sensitivity and Spatial Resolution among Different Collimators and Energy Windows on ²²³Ra Imaging
梅田拓朗; 宮司典明; 中澤脩人; 三輪建太; 我妻慧; 茂木一樹; 滝口智洋; 小泉満
日本放射線技術学会雑誌, 73, 11, 1132, 1139, 2017, [Peer-reviewed]

Evaluation of spatial dependence of point spread function-based PET reconstruction using a traceable point-like 22Na source.
Taisuke Murata; Kenta Miwa; Noriaki Miyaji; Kei Wagatsuma; Tomoyuki Hasegawa; Keiichi Oda; Takuro Umeda; Takashi Iimori; Yoshitada Masuda; Takashi Terauchi; Mitsuru Koizumi
EJNMMI physics, 3, 1, 26, 26, Springer International Publishing, Dec. 2016, [Peer-reviewed], [International Magazine]
English, Scientific journal

Preclinical and first-in-man studies of [(11)C]CB184 for imaging the 18-kDa translocator protein by positron emission tomography.
Jun Toyohara; Muneyuki Sakata; Kentaro Hatano; Shuichi Yanai; Shogo Endo; Kenji Ishibashi; Kei Wagatsuma; Kenji Ishii; Kiichi Ishiwata
Annals of nuclear medicine, 30, 8, 534, 43, Oct. 2016, [Peer-reviewed], [Domestic magazines]
English, Scientific journal

Alteration of the regional cerebral glucose metabolism in healthy subjects by glucose loading.
Kenji Ishibashi; Kei Wagatsuma; Kiichi Ishiwata; Kenji Ishii
Human brain mapping, 37, 8, 2823, 32, Aug. 2016, [Peer-reviewed], [International Magazine]
English, Scientific journal

Report of a nationwide survey on actual administered radioactivities of radiopharmaceuticals for diagnostic reference levels in Japan.
Hiroshi Watanabe; Kazunari Ishii; Makoto Hosono; Etsuko Imabayashi; Koichiro Abe; Masayuki Inubushi; Kazuko Ohno; Yasuhiro Magata; Kinya Ono; Kei Kikuchi; Kei Wagatsuma; Tadashi Takase; Kyoko Saito; Yasuyuki Takahashi
Annals of nuclear medicine, 30, 6, 435, 44, Jul. 2016, [Peer-reviewed], [Domestic magazines]
English, Scientific journal

Scatter limitation correction can avoid scatter correction error caused by a high radioactivity in the facemask in an oxygen-15 labeled gas-inhalation PET study
Wagatsuma Kei; Oda Keiichi; Inaji Motoki; Miwa Kenta; Hayashi Shihori; Sakata Muneyuki; Sasaki Masayuki; Ishiwata Kiichi; Ishii Kenji
JOURNAL OF NUCLEAR MEDICINE, 57, 01 May 2016, [Peer-reviewed]

Comparison of dosimetry between PET/CT and PET alone using (11)C-ITMM.
Kimiteru Ito; Muneyuki Sakata; Keiichi Oda; Kei Wagatsuma; Jun Toyohara; Kenji Ishibashi; Kenji Ishii; Kiichi Ishiwata
Australasian physical & engineering sciences in medicine, 39, 1, 177, 86, Mar. 2016, [Peer-reviewed], [International Magazine]
English, Scientific journal

Evaluation of scatter limitation correction: a new method of correcting photopenic artifacts caused by patient motion during whole-body PET/CT imaging.
Kenta Miwa; Takuro Umeda; Taisuke Murata; Kei Wagatsuma; Noriaki Miyaji; Takashi Terauchi; Mitsuru Koizumi; Masayuki Sasaki
Nuclear medicine communications, 37, 2, 147, 54, Feb. 2016, [Peer-reviewed], [International Magazine]
English, Scientific journal

Evaluation of a New Motion-correction Algorithm Using On-rigid Registration in Respiratory-gated PET/CT Images of Liver Tumors.
Kei Wagatsuma; Tatsufumi Osawa; Naoki Yokokawa; Kenta Miwa; Keiichi Oda; Yoshiro Kudo; Yasushi Unno; Kimiteru Ito; Kenji Ishii
Nihon Hoshasen Gijutsu Gakkai zasshi, 72, 11, 1067, 1073, 2016, [Peer-reviewed], [Lead author], [Domestic magazines]
Japanese, OBJECTIVE: The present study aimed to determine the qualitative and quantitative accuracy of the Q.Freeze algorithm in PET/CT images of liver tumors. METHODS: A body phantom and hot spheres representing liver tumors contained 5.3 and 21.2 kBq/mL of a solution containing 18F radioactivity, respectively. The phantoms were moved in the superior-inferior direction at a motion displacement of 20 mm. Conventional respiratory-gated (RG) and Q.Freeze images were sorted into 6, 10, and 13 phase-groups. The SUVave was calculated from the background of the body phantom, and the SUVmax was determined from the hot spheres of the liver tumors. Three patients with four liver tumors were also clinically assessed by whole-body and RG PET. The RG and Q.Freeze images derived from the clinical study were also sorted into 6, 10 and 13 phase-groups. Liver signal-to-noise ratio (SNR) and SUVmax were determined from the RG and Q.Freeze clinical images. RESULTS: The SUVave of Q.Freeze images was the same as those derived from the body phantom using RG. The liver SNR improved with Q.Freeze, and the SUVsmax was not overestimated when Q.Freeze was applied in both the phantom and clinical studies. Q.Freeze did not degrade the liver SNR and SUVmax even though the phase number was larger. CONCLUSIONS: Q.Freeze delivered qualitative and quantitative motion correction than conventional RG imaging even in 10-phase groups.

Evaluation of a revised version of computer-assisted diagnosis system, BONENAVI version 2.1.7, for bone scintigraphy in cancer patients.
Mitsuru Koizumi; Noriaki Miyaji; Taisuke Murata; Kazuki Motegi; Kenta Miwa; Masamichi Koyama; Takashi Terauchi; Kei Wagatsuma; Kazunori Kawakami; Jens Richter
Annals of nuclear medicine, 29, 8, 659, 65, Oct. 2015, [Peer-reviewed], [Domestic magazines]
English, Scientific journal

Effects of a novel additional neck-shield and time of flight on quality of cerebral imaging in O-15-labeled gas inhalation study
Wagatsuma Kei; Oda Keiichi; Miwa Kenta; Inaji Motoki; Hayashi Shihori; Sakata Muneyuki; Ishibashi Kenji; Toyohara Jun; Ishii Kenji; Ishiwata Kiichi
JOURNAL OF NUCLEAR MEDICINE, 56, 3, 01 May 2015, [Peer-reviewed]

Evaluation of a computer-assisted diagnosis system, BONENAVI version 2, for bone scintigraphy in cancer patients in a routine clinical setting.
Mitsuru Koizumi; Kei Wagatsuma; Noriaki Miyaji; Taisuke Murata; Kenta Miwa; Tomohiro Takiguchi; Tomoko Makino; Masamichi Koyama
Annals of nuclear medicine, 29, 2, 138, 48, Feb. 2015, [Peer-reviewed], [Domestic magazines]
English, Scientific journal

Improvement of Quantitative Accuracy Using Phase-based Respiratory-gated PET/CT in Phantom and Clinical Studies
三輪建太; 三輪建太; 我妻慧; 梅田拓朗; 宮司典明; 村田泰輔; 大澤敦; 滝口智洋; 小泉満; 佐々木雅之
日本放射線技術学会雑誌, 70, 11, 1235, 42, (公社)日本放射線技術学会, Nov. 2014, [Peer-reviewed], [Domestic magazines]
Japanese, OBJECTIVE: The present study aimed at determining the quantitative accuracy of phase-based respiratory-gated PET/CT imaging using phantom and clinical studies. METHODS: The effects of target size, target-to-background ratio (TBR), and respiratory motion on PET images were estimated using a NEMA body phantom comprising six spheres (diameter 10-37mm) in a solution of F-18 of three different TBRs (4, 6, 8). The phantom was moved in a superior-inferior direction at motion displacements of 0, 10, 20 and 30 mm. Stationary images of the phantom as well as non-gated (3D) and gated (4D) images of the phantom while moving were reconstructed and the recovery coefficient (RC) of individual spheres was calculated from each image. We then determined the RC improvement rate to evaluate improvements conferred by 4D-PET/CT. We retrospectively analyzed data from 14 patients with lung cancer who were examined by 3D- and 4D-PET/CT. Each lesion on the 3D-PET/CT and each of the five phases of the 4D-PET/CT were analyzed. RESULTS: Larger motion displacement and TBR resulted in increased RC degradation for small spheres. The RC improvement rate showed that 4D acquisition improved the RC of spheres with larger motion displacement exceeding 13 mm in diameter. 4D-PET/CT alone can reduce the effects of motion blurring, but partial volume effects may still be the dominant source of quantitative inaccuracy for small lesions. The trends of phantom and clinical studies for evaluating the improvement rate were similar. CONCLUSIONS: 4D-PET/CT significantly improved the quantitative accuracy of PET images particularly when larger motion displacement exceeded 17mm in diameter such as in lung cancer.

Optimal radiation shielding for beta and bremsstrahlung radiation emitted by (89)Sr and (90)Y: validation by empirical approach and Monte Carlo simulations.
Taisuke Murata; Kenta Miwa; Fumiyasu Matsubayashi; Kei Wagatsuma; Kenta Akimoto; Toshioh Fujibuchi; Noriaki Miyaji; Tomohiro Takiguchi; Masayuki Sasaki; Mitsuru Koizumi
Annals of nuclear medicine, 28, 7, 617, 22, Aug. 2014, [Peer-reviewed], [Domestic magazines]
English, Scientific journal

FDG uptake heterogeneity evaluated by fractal analysis improves the differential diagnosis of pulmonary nodules.
Kenta Miwa; Masayuki Inubushi; Kei Wagatsuma; Michinobu Nagao; Taisuke Murata; Masamichi Koyama; Mitsuru Koizumi; Masayuki Sasaki
European journal of radiology, 83, 4, 715, 9, Apr. 2014, [Peer-reviewed], [International Magazine]
English, Scientific journal

Comparison of ¹⁸F-fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computed Tomography Image Quality between Commercial and In-house Supply of FDG Radiopharmaceuticals
我妻慧; 三輪建太; 宮司典明; 村田泰輔; 梅田拓朗; 大澤敦; 滝口智洋; 小泉満
日本放射線技術学会雑誌, 70, 4, 339, 45, Apr. 2014, [Peer-reviewed], [Lead author], [Domestic magazines]
Japanese, OBJECTIVE: PET images are affected by scanner model, reconstruction conditions, injected dose, scan duration, patient health status and FDG radiopharmaceutical supply systems. The present study compares images of 40 patients using commercial and in-house FDG systems with one PET scanner (Aquiduo). METHODS: The PET images were evaluated using the physical indexes of NECpatient, NECdensity and SNRliver proposed by the Japanese guidelines for oncological FDG-PET/CT, and by visual assessment. RESULTS: There were no significant differences in the physical indexes between PET images generated using commercial and in-house FDG. The physical indexes were also acceptable according to the recommended Japanese guidelines. NECdensity was higher when a higher dose/body weight of commercial FDG was injected (correlation coefficient: r=0.576, p<0.001) and lower when BMI was lower and in-house FDG was injected (r=-0.786, p<0.0001). These results suggest that scan duration should be increased if the injected dose of commercial FDG/body weight is <5.5 MBq/kg, and if individuals with BMI >21.4 kg/m(2) are injected with in-house FDG. CONCLUSIONS: Scan duration should be varied depending on FDG supply systems to ensure more accurate image quality and quantitative values during evaluations of response to therapy and prognostic prediction.

Technical features and roles of cobalt-57 flood sources for daily quality control of gamma cameras
我妻慧; 三輪建太; 秋本健太; 對間博之; 宮司典明; 梅田拓朗; 村田泰輔; 滝口智洋; 小泉満
日本放射線技術学会雑誌, 70, 2, 148, 53, Feb. 2014, [Peer-reviewed], [Lead author], [Domestic magazines]
Japanese, Quality control (QC) detects changes in the performance of gamma cameras that could adversely affect interpretations of clinical studies. We used plate and sheet (57)Co flood sources to measure extrinsic uniformity during daily QC. Each source, when placed on the top of a collimated detector, allowed the acquisition of uniform images from both detectors, thus reducing the amount of time needed to perform daily QC. No serious problems with the gamma camera system were revealed by visual checks, and changes in detector sensitivity were rapidly determined by observing daily variations in the measured values of extrinsic uniformity. Furthermore, (57)Co flood sources confer advantages in that they shorten the time required for preparation of flood sources and reduce the consequent exposure of medical staff to radiation.

Quality Control of Dose Calibrator Using a Traceable Syringe-type ⁶⁸Ge/⁶⁸Ga Calibration Source
宮司典明; 三輪建太; 我妻慧; 梅田拓朗; 村田泰輔; 滝口智洋; 小泉満
日本放射線技術学会雑誌, 69, 12, 1379, 86, Dec. 2013, [Peer-reviewed], [Domestic magazines]
Japanese, OBJECTIVES: Accurate calibration of dose calibrators (DC) is required for quantitative positron emission tomography (PET) studies to generate meaningful information. Values measured by DC depend not only on the radioactive nuclide but also the environment where measurements are taken. Therefore, DC must be calibrated at each location. The present study aimed to determine appropriate calibration values, and evaluate the performance of DC using a traceable (68)Ge/(68)Ga calibration source that is available as a surrogate (18)F source. METHODS: We used a (68)Ge/(68)Ga calibration source to determine the optimal DC value for measuring (18)F activity in the operating environment. Variations in sensitivity and geometry as well as measurement uncertainty were evaluated using the (68)Ge/(68)Ga source. We adopted the criteria of the Guide for the expression of uncertainty in measurement (GUM) to evaluate DC performance. RESULTS: Although the manufacturer's recommended (18)F calibration number for the CRC-25PET is 480, we found that the optimal number was 482. Over a period of one year, the sensitivity of the DC varied <0.1%, and the expanded uncertainty of DC measurements was 2.2%. CONCLUSION: Measurements of the certified activity of a traceable national standard were corrected, and the uncertainty of measurements as well as the accuracy of a DC were determined. Calibration numbers for DC should be regularly determined using (68)Ge/(68)Ga calibration sources at each location to ensure the most accurate results.

Validation of novel calibration scheme with traceable point-like (22)Na sources on six types of PET scanners.
Tomoyuki Hasegawa; Keiichi Oda; Yasuhiro Wada; Toshiaki Sasaki; Yasushi Sato; Takahiro Yamada; Mikio Matsumoto; Hideo Murayama; Kei Kikuchi; Hiroki Miyatake; Yutaka Abe; Kenta Miwa; Kenta Akimoto; Kei Wagatsuma
Annals of nuclear medicine, 27, 4, 346, 54, May 2013, [Peer-reviewed], [Domestic magazines]
English, Scientific journal

Relationship between Image Quality and Cross-sectional Area of Phantom in Three-dimensional Positron Emission Tomography Scan
大澤敦; 三輪建太; 我妻慧; 滝口智洋; 田村慎太郎; 秋本健太
日本放射線技術学会雑誌, 68, 12, 1600, 7, 2012, [Peer-reviewed], [Domestic magazines]
Japanese, The image quality in (18)FDG PET/CT often degrades as the body size increases. The purpose of this study was to evaluate the relationship between image quality and the body size using original phantoms of variable cross-sectional areas in PET/CT. We produced five water phantoms with different cross-sectional areas. The long axis of phantom was 925 mm, and the cross-sectional area was from 324 to 1189 cm(2). These phantoms with the sphere (diameter 10 mm) were filled with (18)F-FDG solution. The radioactivity concentration of background in the phantom was 1.37, 2.73, 4.09 and 5.46 kBq/mL. The scanning duration was 30 min in list mode acquisition for each measurement. Background variability (N(10 mm)), noise equivalent count rates (NECR(phantom)), hot sphere contrast (Q(H,10 mm)) as physical evaluation and visual score of sphere detection were measured, respectively. The relationship between image quality and the various cross-sectional areas was also analyzed under the above-mentioned conditions. As cross-sectional area increased, NECR(phantom) progressively decreased. Furthermore, as cross-sectional area increased, N(10 mm) increased and Q(H,10 mm) decreased. Image quality became degraded as body weight increased because noise and contrast contributed to image quality. The visual score of sphere detection deteriorated in high background radioactivity concentration because a false positive detection in cross-sectional area of the phantom increased. However, additional increases in scanning periods could improve the visual score. We assessed tendencies in the relationship between image quality and body size in PET/CT. Our results showed that time adjustment was more effective than dose adjustment for stable image quality of heavier patients in terms of the large cross-sectional area.

Respiratory Management of CT-transmission for Accuracy Fusion in PET/CT: A Comparison between Normal Expiration and Free Breathing in 600 Experiences
大澤敦; 滝口智洋; 田村慎太郎; 大橋聖; 三輪建太; 秋本健太; 我妻慧
日本放射線技術学会雑誌, 66, 7, 743, 8, Jul. 2010, [Peer-reviewed], [Domestic magazines]
Japanese, Image misregistration can occur in fusion PET/CT, because of motion artifacts caused by the management of respiration. The standard imaging protocol of the CT component of PET/CT is normal expiration (NormExp) or free breathing (FB). The objective of this study was to compare NormExp and FB for the optimal breathing protocol for PET/CT scans. A total of 600 consecutive patients were examined using lutetium oxyorthosilicate (LSO)-based PET/CT. CT was acquired during NormExp (i.e., the level reached when the patient exhaled without forcing expiration and then held the breath) in 300 patients and during FB in 300 patients. The profile of liver measured along body axis was assessed. The distance of profile centers between the PET image and the CT image was measured. The misalignment between profile centers (PET) and profile centers (CT) was compared between NormExp and FB using the histogram of patients. An F test was used to test if the variances of two misalignments are equal. Next, the relationship between misalignment and age was evaluated in two managements of respiration. There was no significant difference between NormExp and FB in the histogram. However, significant misalignments (>10 cm) were found with NormExp. Patient age may have influenced the mismatch. FB is recommended for geriatric patients during acquisition of attenuation correction CT data sets.

シン・核医学の世界⑧半導体PET/CT装置
三輪建太; 我妻慧; 宮司典明; 山尾天翔; 上髙祐人, 日本診療放射線技師会誌, 72, 73, 80, Jul. 2025
Japanese, Introduction scientific journal

シン・核医学の世界⑤アミロイドPETの撮影技術
我妻慧; 三輪建太; 上髙祐人; 山尾天翔; 宮司典明, 日本診療放射線技師会誌, 72, 3, 307, 314, Mar. 2025, [Lead author]
Japanese, Introduction scientific journal

Under-modeling PSF補正とHybrid-PSF補正の基礎的検討
平川大空; 我妻慧; 我妻慧; 坂田宗之; 上高祐人; 甲木晶枝; 川上泰史; 石井賢二, 核医学技術, 45, 2025

Phantom Study for Amyloid and Tau PET Imaging
Kei Wagatsuma; Kenta Miwa; Yuto Kamitaka; Tensho Yamao; Go Akamatsu; Shohei Fukuda; Muneyuki Sakata; Noriaki Miyaji; Kenji Ishii, Japanese Journal of Radiological Technology, 80, 11, 1233, 1243, 20 Nov. 2024, [Lead author]
Japanese Society of Radiological Technology, Japanese, Introduction scientific journal, 31628848;45875360

SiPM-PET/CT装置の体軸方向視野による11C-メチオニン脳PET画像の低コントラストおよび微小病変への影響
廿樂 楓; 我妻 慧; 横塚 記代; 上高 祐人; 三輪 建太; 谷本 克之; 西井 龍一; 石井 賢二, 日本放射線技術学会東京支部雑誌, 136, 26, 26, Sep. 2022
(公社)日本放射線技術学会-東京支部, Japanese

高空間分解能PETのためのBPL法の罰則関数内γfactorの検討
三輪 建太; 吉井 斗輝也; 根津 翔吾; 我妻 慧; 山尾 天翔; 上高 祐人, 核医学技術, 41, 予稿集, 393, 393, Oct. 2021
(NPO)日本核医学技術学会, Japanese

11C-methionine PETにおける4-ringと5-ringのPET/CT装置の物理評価の比較
上高 祐人; 廿樂 楓; 我妻 慧; 三輪 建太; 谷本 克之; 西井 龍一; 石井 賢二, 核医学技術, 41, 予稿集, 414, 414, Oct. 2021
(NPO)日本核医学技術学会, Japanese

アミロイドPETに対する領域分割Centiloid scaleの評価
山尾 天翔; 三輪 建太; 重本 蓉子; 我妻 慧; 上高 祐人; 伊藤 浩; 松田 博史, 核医学技術, 41, 予稿集, 414, 414, Oct. 2021
(NPO)日本核医学技術学会, Japanese

高齢者地域コホートにおける脳内アミロイド蓄積と局所脳容積について
今林 悦子; 石井 賢二; 豊原 潤; 坂田 宗之; 我妻 慧; 石橋 賢士; 多胡 哲郎; 徳丸 阿耶; 小島 成実; 小林 洋大; 甲田 哲之; 金 憲経, Dementia Japan, 35, 4, 615, 615, Oct. 2021
(一社)日本認知症学会, Japanese

タウPETイメージングの標準的撮像法の確立を目的とした多施設共同研究
我妻 慧; 三輪 建太; 赤松 剛; 山尾 天翔; 上高 祐人; 藤田 尚利; 櫻井 実; 花岡 宏平, 日本放射線技術学会雑誌, 77, 9, 1128, 1128, Sep. 2021
(公社)日本放射線技術学会, Japanese

11C-メチオニン脳PETにおけるBayesian Penalized Likelihood法を用いた微小および低コントラスト病変への最適化
廿樂 楓; 我妻 慧; 横塚 記代; 三輪 建太; 上高 祐人; 谷本 克之; 石井 賢二, 日本放射線技術学会総会学術大会予稿集, 77回, 219, 219, Mar. 2021
(公社)日本放射線技術学会, Japanese

11C-メチオニン脳PETにおけるBayesian Penalized Likelihood法を用いた微小および低コントラスト病変への最適化
廿樂 楓; 我妻 慧; 横塚 記代; 三輪 建太; 上高 祐人; 谷本 克之; 石井 賢二, 日本放射線技術学会総会学術大会予稿集, 77回, 219, 219, Mar. 2021
(公社)日本放射線技術学会, Japanese

SPMを用いた脳FDG画像の統計比較における新旧機種の機種間差補正の検討
坂田 宗之; 我妻 慧; 織田 圭一; 今林 悦子; 上高 祐人; 石橋 賢士; 多胡 哲郎; 豊原 潤; 石井 賢二, 核医学, 58, Suppl., S198, S198, 2021
(一社)日本核医学会, Japanese

新規P-糖タンパク質イメージング剤[18F]MC225の初期臨床評価
豊原 潤; 坂田 宗之; 石橋 賢士; 我妻 慧; 多胡 哲郎; 今林 悦子; Colabufo Nicola; Luurtsema Gert; 石井 賢二, 核医学, 58, Suppl., S205, S205, 2021
(一社)日本核医学会, Japanese

新規P-糖タンパク質イメージング剤[18F]MC225の全身PET計測による被ばく線量評価
豊原 潤; 坂田 宗之; 石橋 賢士; 我妻 慧; 多胡 哲郎; 今井 昌康; Colabufo Nicola; Luurtsema Gert; 石井 賢二, 核医学, 58, Suppl., S205, S205, 2021
(一社)日本核医学会, Japanese

プレクリニカル期アルツハイマー病における側頭葉内側部の容積について
今林 悦子; 石井 賢二; 豊原 潤; 坂田 宗之; 我妻 慧; 石橋 賢士; 多胡 哲郎; 徳丸 阿耶; 小島 成美; 小林 洋大; 金 憲経, 核医学, 58, Suppl., S223, S223, 2021
(一社)日本核医学会, Japanese

医療放射線に係るリスクコミュニケーションの実態調査研究
大塚駿; 大塚駿; 新井知大; 熊坂さつき; 吉川宏起; 堀川大輔; 篠ヶ瀬知; 菅原康晴; 我妻慧, 医療の広場, 61, 3, 2021

核医学検査機器の保守点検の重要性
我妻慧, 核医学技術, 41, 1, 125, 128, 2021
(NPO)日本核医学技術学会, Japanese

虚血性脳血管障害における運動中の脳血流量の特徴 PET研究
日浦 幹夫; 成相 直; 坂田 宗之; 石橋 賢士; 我妻 慧; 多胡 哲郎; 豊原 潤; 石井 賢二; 片山 容一, 核医学, 57, Suppl., S143, S143, Oct. 2020
(一社)日本核医学会, Japanese

FDG画像の機械学習を用いた認知症鑑別診断支援における特徴量増加による精度向上の検討
坂田 宗之; 我妻 慧; 多胡 哲郎; 石橋 賢士; 豊原 潤; 石井 賢二, 核医学, 57, Suppl., S156, S156, Oct. 2020
(一社)日本核医学会, Japanese

IstradefyllineによるアデノシンA2A受容体占拠率
石橋 賢士; 多胡 哲郎; 我妻 慧; 坂田 宗之; 豊原 潤; 石井 賢二, 核医学, 57, Suppl., S164, S164, Oct. 2020
(一社)日本核医学会, English

定量とその不確かさ PET測定における定量と精度管理
我妻 慧; 坂田 宗之; 三輪 建太; 宮司 典明, 日本放射線技術学会雑誌, 76, 4, 437, 443, Apr. 2020
(公社)日本放射線技術学会, Japanese

[18F]fluciclovineアミノ酸脳腫瘍PETにおけるBayesian Penalized Likelihood法を用いた至適β値の検討
廿樂 楓; 我妻 慧; 横塚 記代; 三輪 建太; 石井 賢二, 日本放射線技術学会総会学術大会予稿集, 76回, 187, 188, Mar. 2020
(公社)日本放射線技術学会, Japanese

アルツハイマー病に対するPET、MRI画像を用いた病理学的分類法の評価
山尾 天翔; 三輪 建太; 我妻 慧; 松田 博史, 日本放射線技術学会総会学術大会予稿集, 76回, 239, 239, Mar. 2020
(公社)日本放射線技術学会, Japanese

[18F]flutemetamolアミロイドPETにおけるBayesian Penalized Likelihood法の有用性
我妻 慧; 坂田 宗之; 石橋 賢士; 平山 昭; 川上 泰史; 三輪 建太; 石井 賢二, 日本放射線技術学会総会学術大会予稿集, 76回, 237, 238, Mar. 2020
(公社)日本放射線技術学会, Japanese

SiPM-PET/CT装置『Discovery MI』の臨床的な有用性
我妻慧, 核医学技術, 40, 1, 2020

10. Quantitative Measurement and Quality Control in Positron Emission Tomography
我妻慧; 坂田宗之; 三輪建太; 宮司典明, 日本放射線技術学会雑誌, 76, 4, 2020

IstradefyllineによるアデノシンA2A受容体占拠率
石橋賢士; 多胡哲郎; 我妻慧; 坂田宗之; 豊原潤; 石井賢二, 核医学(Web), 57, Supplement, 2020

虚血性脳血管障害における運動中の脳血流量の特徴:PET研究
日浦幹夫; 成相直; 成相直; 坂田宗之; 石橋賢士; 我妻慧; 多胡哲郎; 豊原潤; 石井賢二; 片山容一, 核医学(Web), 57, Supplement, 2020

FDG画像の機械学習を用いた認知症鑑別診断支援における特徴量増加による精度向上の検討
坂田宗之; 我妻慧; 多胡哲郎; 石橋賢士; 豊原潤; 石井賢二, 核医学(Web), 57, Supplement, 2020

Study of the activation evaluation method for metallic iron using a PET cyclotron
松村宏; 桝本和義; 吉田剛; 豊田晃弘; 中村一; 三浦太一; 齊藤勝彦; 甲村巌根; 鵜野浩行; 小嵜正彦; 我妻慧, 日本放射線安全管理学会学術大会講演予稿集, 19th, 2020

核医学検査機器の保守点検の重要性
我妻慧, 核医学技術, 40, 予稿集, 321, 321, 2020
(NPO)日本核医学技術学会, Japanese

[¹⁸F]florbetapirアミロイドPETイメージングの解析ソフトウェアの比較検証
我妻慧; 三輪建太; 石橋賢士; 坂田宗之; 石井賢二, 核医学技術, 40, 予稿集, 338, 338, 2020
(NPO)日本核医学技術学会, Japanese

[¹⁸F]flutemetamolアミロイドPETにおけるBayesian Penalized Likelihood法の有用性
我妻慧; 坂田宗之; 石橋賢士; 平山昭; 川上泰史; 三輪建太; 石井賢二, 日本放射線技術学会総会学術大会予稿集, 76th, 237, 238, 2020
(公社)日本放射線技術学会, Japanese

最新半導体PET装置って実際どうなん?各装置徹底比較! SiPM-PET/CT装置『Discovery MI』の臨床的な有用性
我妻 慧, 核医学技術, 40, 1, 100, 103, Jan. 2020
(NPO)日本核医学技術学会, Japanese

Adenosine A_2A receptors in Parkinson’s disease
石橋賢士; 多胡哲朗; 我妻慧; 坂田宗之; 豊原潤; 石井賢二, 臨床薬理の進歩, 41, 15, 23, 2020
パーキンソン病(PD)におけるアデノシンA2A受容体の病態解析の第一歩として、アデノシンA2A受容体拮抗薬であるistradefyllineのアデノシンA2A受容体に対する占拠率を測定した。PD患者10例(平均74.9±8.2歳)と健常者6例(平均76.8±7.1歳)を対象とした。PD患者はランダムにistradefylline-20mg群(n=5)とistradefylline-40mg群(n=5)に分類し、istradefylline-20mg群にはistradefylline 20mgを、istradefylline-40mg群にはistradefylline 40mgをそれぞれ単回経口投与した。istradefyllineの内服前後に11C-preladenant PETを行った。2種のX軸変数、「用量」と「用量/体表面積」を用いて受容体占拠率曲線を推定したところ、istradefyllineによるアデノシンA2A、受容体占拠率を算出するときはx軸変数としてより簡便な「用量」が使用できると言える結果となった。本研究では、腹側線条体と背側線条体(尾状核と被殻)の間で、最大受容体占拠率とED50に、比較的大きな差を認めた。腹側線条体では、最大受容体占拠率93.5%、ED50 28.6mgであり、背側線条体では、最大受容体占拠率65〜70%、ED50 10〜15mgであった。健常者群とPD群の間で、BPNDに有意差を認めなかった。ジスキネジアを有した1例のPD患者のBPNDがやや高い傾向にあった。また、健常群に比べてPD群では、BPNDが個人間で大きくばらついた。, (公財)臨床薬理研究振興財団, Japanese

[¹⁸F]fluciclovineアミノ酸脳腫瘍PETにおけるBayesian Penalized Likelihood法を用いた至適β値の検討
廿樂楓; 我妻慧; 横塚記代; 三輪建太; 石井賢二, 日本放射線技術学会総会学術大会予稿集, 76th, 187, 188, 2020
(公社)日本放射線技術学会, Japanese

アルツハイマー病に対するPET,MRI画像を用いた病理学的分類法の評価
山尾天翔; 山尾天翔; 三輪建太; 我妻慧; 松田博史, 日本放射線技術学会総会学術大会予稿集, 76th, 239, 239, 2020
(公社)日本放射線技術学会, Japanese

最新半導体PET装置って実際どうなん?各装置徹底比較! SiPM-PET/CT装置『Discovery MI』の臨床的な有用性
我妻 慧, 核医学技術, 39, 予稿集, 321, 321, Oct. 2019
(NPO)日本核医学技術学会, Japanese

異なるPET装置におけるアミロイドPETの短時間収集の可能性
我妻 慧; 石橋 賢士; 三輪 建太; 坂田 宗之; 石井 賢二, 核医学技術, 39, 予稿集, 355, 355, Oct. 2019
(NPO)日本核医学技術学会, Japanese

[11C]PiBアミロイドPETと[18F]THK5351タウPETに対するCentiloid scaleによる定量的比較
山尾 天翔; 三輪 建太; 我妻 慧; 安保 哉太; 松田 博史, 核医学技術, 39, 予稿集, 356, 356, Oct. 2019
(NPO)日本核医学技術学会, Japanese

Bayesian Penalized Likelihood画像再構成法における定量精度の機種依存性
吉井 斗輝也; 三輪 建太; 宮司 典明; 我妻 慧; 山尾 天翔, 核医学技術, 39, 予稿集, 384, 384, Oct. 2019
(NPO)日本核医学技術学会, Japanese

[18F] florbetapir PETにおける白質参照領域の優位性の源泉
亀山 征史; 石橋 賢士; 我妻 慧; 豊原 潤; 石井 賢二, 核医学, 56, Suppl., S143, S143, Oct. 2019
(一社)日本核医学会, Japanese

アクリル吸収体Ge-68/Ga-68タイプトレーサブル点状線源を用いる定量性・校正定数評価法の開発状況報告
長谷川 智之; 岡本 美桜; 高橋 健太郎; 宮武 比呂樹; 菊池 敬; 井上 優介; 織田 圭一; 我妻 慧; 和田 康弘, 核医学, 56, Suppl., S165, S165, Oct. 2019
(一社)日本核医学会, Japanese

早期アルツハイマー病における代謝型グルタミン酸受容体1型
石橋 賢士; 多胡 哲郎; 我妻 慧; 坂田 宗之; 豊原 潤; 石井 賢二, 核医学, 56, Suppl., S174, S174, Oct. 2019
(一社)日本核医学会, English

11C-preladenantを用いたアデノシンA2A受容体定量測定の再現性検討
坂田 宗之; 我妻 慧; 多胡 哲郎; 石橋 賢士; 石井 賢二; 石渡 喜一; 豊原 潤, 核医学, 56, Suppl., S178, S178, Oct. 2019
(一社)日本核医学会, English

Off-target bindingを有するアミロイド・タウPETトレーサーのための特異集積量推定法
徳田 明日香; 田中 美香; 多胡 哲郎; 石橋 賢士; 我妻 慧; 坂田 宗之; 井上 一雅; 福士 政広; 豊原 潤; 石井 賢二, 核医学, 56, Suppl., S143, S143, Oct. 2019
(一社)日本核医学会, Japanese

Off-target bindingを有するアミロイド・タウPETトレーサーのための特異集積量推定法
徳田 明日香; 田中 美香; 多胡 哲郎; 石橋 賢士; 我妻 慧; 坂田 宗之; 井上 一雅; 福士 政広; 豊原 潤; 石井 賢二, 核医学, 56, Suppl., S143, S143, Oct. 2019
(一社)日本核医学会, Japanese

核医学領域における水晶体被ばくの実態に関する基礎検討
宮司 典明; 飯森 隆志; 對間 博之; 横塚 記代; 我妻 慧; 三輪 建太; 村田 泰輔; 笠原 哲治, 日本放射線技術学会雑誌, 75, 9, 1070, 1070, Sep. 2019
(公社)日本放射線技術学会, Japanese

囲碁を活用した認知機能低下抑制プログラムの評価 FDG-PETを用いた脳糖代謝に対する介入効果の検討
飯塚 あい; 石井 賢二; 我妻 慧; 石橋 賢士; 大西 愛鈴; 田中 美香; 鈴木 宏幸; 粟田 主一; 藤原 佳典, 日本老年医学会雑誌, 56, Suppl., 135, 135, May 2019
(一社)日本老年医学会, Japanese

Measurement Principles and Clinical Applications of Positron Emission Tomography
坂田宗之; 我妻慧, 計測と制御, 58, 7, 2019

SiPM-PET/CT装置『Discovery MI』の臨床的な有用性
我妻慧, 核医学技術, 39, 2019

早期アルツハイマー病における代謝型グルタミン酸受容体1型
石橋賢士; 多胡哲郎; 我妻慧; 坂田宗之; 豊原潤; 石井賢二, 核医学(Web), 56, Supplement, 2019

¹¹C-preladenantを用いたアデノシンA_2A受容体定量測定の再現性検討
坂田宗之; 我妻慧; 多胡哲郎; 石橋賢士; 石井賢二; 石渡喜一; 石渡喜一; 石渡喜一; 豊原潤, 核医学(Web), 56, Supplement, 2019

[¹⁸F]florbetapir PETにおける白質参照領域の優位性の源泉
亀山征史; 石橋賢士; 我妻慧; 豊原潤; 石井賢二, 核医学(Web), 56, Supplement, 2019

アクリル吸収体Ge-68/Ga-68タイプトレーサブル点状線源を用いる定量性・校正定数評価法の開発状況報告
長谷川智之; 岡本美桜; 高橋健太郎; 宮武比呂樹; 菊池敬; 井上優介; 井上優介; 織田圭一; 我妻慧; 和田康弘, 核医学(Web), 56, Supplement, 2019

Off-target bindingを有するアミロイド・タウPETトレーサーのための特異集積量推定法
徳田明日香; 徳田明日香; 田中美香; 多胡哲郎; 石橋賢士; 我妻慧; 坂田宗之; 井上一雅; 福士政広; 豊原潤; 石井賢二, 核医学(Web), 56, Supplement, 2019

アルツハイマー型認知症の超早期診断のためのアミロイド・タウPETの定量評価法の開発・評価
三輪建太; 平塚勢哉; 木村周平; 我妻慧, 医療の広場, 59, 4, 2019

18F-FDG PETを用いた内側側頭葉てんかんの焦点側診断におけるSPM統計解析
林志保里; 稲次基希; 成相直; 我妻慧; 坂田宗之; 石井賢二; 前原健寿, てんかん研究, 37, 2, 544, 544, 2019
(一社)日本てんかん学会, Japanese

囲碁を活用した認知機能低下抑制プログラムの評価 FDG-PETを用いた脳糖代謝に対する介入効果の検討
飯塚 あい; 石井 賢二; 我妻 慧; 石橋 賢士; 大西 愛鈴; 田中 美香; 鈴木 宏幸; 粟田 主一; 藤原 佳典, 日本老年医学会雑誌, 56, Suppl., 135, 135, 2019
(一社)日本老年医学会, Japanese

核医学領域における水晶体被ばくの実態に関する基礎検討
宮司 典明; 飯森 隆志; 對間 博之; 横塚 記代; 我妻 慧; 三輪 建太; 村田 泰輔; 笠原 哲治, 日本放射線技術学会雑誌, 75, 9, 1070, 1070, 2019
(公社)日本放射線技術学会, Japanese

異なるPET装置におけるアミロイドPETの短時間収集の可能性
我妻 慧; 石橋 賢士; 三輪 建太; 坂田 宗之; 石井 賢二, 核医学技術, 39, 予稿集, 355, 355, 2019
(NPO)日本核医学技術学会, Japanese

[11C]PiBアミロイドPETと[18F]THK5351タウPETに対するCentiloid scaleによる定量的比較
山尾 天翔; 三輪 建太; 我妻 慧; 安保 哉太; 松田 博史, 核医学技術, 39, 予稿集, 356, 356, 2019
(NPO)日本核医学技術学会, Japanese

Bayesian Penalized Likelihood画像再構成法における定量精度の機種依存性
吉井 斗輝也; 三輪 建太; 宮司 典明; 我妻 慧; 山尾 天翔, 核医学技術, 39, 予稿集, 384, 384, 2019
(NPO)日本核医学技術学会, Japanese

SCA6における代謝型グルタミン酸受容体1型の経時的変化
石橋 賢士; 三浦 義治; 我妻 慧; 豊原 潤; 石井 賢二, 核医学, 55, Suppl., S167, S167, Nov. 2018
(一社)日本核医学会, English

良性髄内腫瘍における11C methionine PETイメージ
稲次 基希; 成相 直; 林 志保里; 黒羽 真砂恵; 田村 郁; 我妻 慧; 豊原 潤; 石井 賢二; 前原 健寿, 核医学, 55, Suppl., S194, S194, Nov. 2018
(一社)日本核医学会, Japanese

運動に伴う脳血流の再分布と脳血管自動調節能の検討 PET研究
日浦 幹夫; 成相 直; 坂田 宗之; 牟田 光孝; 石橋 賢士; 我妻 慧; 多胡 哲郎; 豊原 潤; 石井 賢二; 前原 健寿; 片山 容一, 核医学, 55, Suppl., S212, S212, Nov. 2018
(一社)日本核医学会, English

脳PETのregularized reconstructionにおける分解能補正の影響
坂田 宗之; 我妻 慧; 平山 明; 川上 泰史; 豊原 潤; 石井 賢二, 核医学, 55, Suppl., S235, S235, Nov. 2018
(一社)日本核医学会, English

PET核種製造用サイクロトロン本体と周辺機器の放射化評価
我妻 慧; 功刀 正行; 織田 圭一; 三輪 建太; 豊原 潤; 石井 賢二, 核医学, 55, Suppl., S215, S215, Nov. 2018
(一社)日本核医学会, English

11C-PiB画像に対する部分容積効果補正法の組合せによる定量性の評価
山尾 天翔; 三輪 建太; 松原 佳亮; 我妻 慧; 上高 祐人; 根本 玲央; 松田 博史, 核医学, 55, Suppl., S236, S236, Nov. 2018
(一社)日本核医学会, Japanese

有酸素運動に伴う脳血流量変化の背景としての脳血管自動調節能とneurovascular couplingの考察 PET研究
日浦 幹夫; 成相 直; 坂田 宗之; 牟田 光孝; 石橋 賢士; 我妻 慧; 多胡 哲郎; 豊原 潤; 石井 賢二; 前原 健寿; 片山 容一, 脳循環代謝, 30, 1, 101, 101, Oct. 2018
日本脳循環代謝学会, Japanese

未治療パーキンソン病における脳内代謝型グルタミン酸受容体1型密度 [C-11]ITMM PET研究
三品 雅洋; 鈴木 正彦; 石井 賢二; 石橋 賢士; 坂田 宗之; 我妻 慧; 豊原 潤; 張 明栄; 石渡 喜一; 木村 和美, パーキンソン病・運動障害疾患コングレスプログラム・抄録集, 12回, 93, 93, Jul. 2018
Movement Disorder Society of Japan (MDSJ), Japanese

核医学実験の核心に迫る:PET実験編 脳PET領域での研究法
我妻慧, 日本放射線技術学会核医学部会誌(Web), 39, 1, 2018

有酸素運動に伴う脳血流量変化の背景としての脳血管自動調節能とneurovascular couplingの考察;PET研究
日浦幹夫; 成相直; 成相直; 坂田宗之; 牟田光孝; 石橋賢士; 我妻慧; 多胡哲郎; 豊原潤; 石井賢二; 前原健寿; 片山容一, 脳循環代謝(Web), 30, 1, 2018

11C-PiB画像に対する部分容積効果補正法の組合せによる定量性の評価
山尾天翔; 山尾天翔; 三輪建太; 松原佳亮; 我妻慧; 上高祐人; 根本玲央; 松田博史, 核医学(Web), 55, Supplement, 2018

脳PETのregularized reconstructionにおける分解能補正の影響
坂田宗之; 我妻慧; 平山明; 川上泰史; 豊原潤; 石井賢二, 核医学(Web), 55, Supplement, 2018

良性髄内腫瘍における11C methionine PETイメージ
稲次基希; 稲次基希; 成相直; 成相直; 林志保里; 林志保里; 黒羽真砂恵; 田村郁; 我妻慧; 豊原潤; 石井賢二; 前原健寿, 核医学(Web), 55, Supplement, 2018

SCA6における代謝型グルタミン酸受容体1型の経時的変化
石橋賢士; 三浦義治; 我妻慧; 豊原潤; 石井賢二, 核医学(Web), 55, Supplement, 2018

運動に伴う脳血流の再分布と脳血管自動調節能の検討;PET研究
日浦幹夫; 日浦幹夫; 成相直; 成相直; 坂田崇之; 牟田光孝; 石橋賢士; 我妻慧; 多胡哲郎; 豊原潤; 石井賢二; 前原健寿; 片山容一, 核医学(Web), 55, Supplement, 2018

PET核種製造用サイクロトロン本体と周辺機器の放射化評価
我妻慧; 功刀正行; 織田圭一; 織田圭一; 三輪建太; 豊原潤; 石井賢二, 核医学(Web), 55, Supplement, 2018

核医学実験の核心に迫る:PET実験編 脳PET領域での研究法
我妻慧, 日本放射線技術学会核医学部会誌(Web), 39, 2, 2018

核医学実験の核心にせまる:PET実験編 脳PET領域での研究法
我妻慧, 日本放射線技術学会総会学術大会予稿集, 74th, 113, 113, 2018
(公社)日本放射線技術学会, Japanese

SiPM搭載型PET/CTにおける¹⁸F-FDG-PET検査の最適収集時間の検討
伊藤希; 我妻慧; 小野貴史; 宮崎海峰; 工藤善朗; 海野泰; 亀山征史, 日本放射線技術学会総会学術大会予稿集, 74th, 313, 313, 2018
(公社)日本放射線技術学会, Japanese

未治療パーキンソン病における脳内代謝型グルタミン酸受容体1型密度-[C-11]ITMM PET研究-
三品雅洋; 鈴木正彦; 鈴木正彦; 石井賢二; 石橋賢士; 坂田宗之; 我妻慧; 豊原潤; 張明栄; 石渡喜一; 石渡喜一; 石渡喜一; 木村和美, パーキンソン病・運動障害疾患コングレスプログラム・抄録集, 12th, 93, 93, 2018
Movement Disorder Society of Japan (MDSJ), Japanese

¹⁸F-NaF PET/CTにおける金属アーチファクト低減処理による人工膝関節周囲組織のSUVの評価
平塚勢哉; 三輪建太; 小野貴史; 我妻慧, 日本放射線技術学会雑誌, 74, 9, 991, 991, 2018
(公社)日本放射線技術学会, Japanese

視覚評価によるサブセンチ微小球検出のためのBayesian Penalized Likelihood法のPET至適条件の検討
高橋裕人; 三輪建太; 我妻慧; 上高祐人; 増渕正輝; 成瀬正理; 比嘉友里奈, 日本放射線技術学会雑誌, 74, 9, 991, 991, 2018
(公社)日本放射線技術学会, Japanese

トレーサブル点状線源とファントムを組み合わせる定量性評価法
岡本美桜; 長谷川智之; 長谷川智之; 宮武比呂樹; 菊池敬; 井上優介; 我妻慧; 織田圭一; 和田康弘, 核医学技術, 38, 予稿集, 411, 411, 2018
(NPO)日本核医学技術学会, Japanese

異なるアミロイドPET製剤による脳内放射能濃度分布の定量的比較
JIANG Muladili Tusong; 三輪建太; 山尾天翔; 山尾天翔; 山口将司; 高橋裕人; 我妻慧; 赤松剛, 日本放射線技術学会雑誌, 74, 9, 993, 994, 2018
(公社)日本放射線技術学会, Japanese

SiPM-PET装置における18F標識アミロイドPETイメージングの撮像時間の検討 ファントム実験
我妻 慧; 三輪 建太; 坂田 宗之; 織田 圭一; 石井 賢二, 日本放射線技術学会東京支部雑誌, 133, 26, 26, 2018
(公社)日本放射線技術学会-東京支部, Japanese

アルツハイマー型認知症の超早期診断のためのアミロイドPETの新しい定量評価法の評価
三輪 建太; 平塚 勢哉; 根本 玲央; 木村 周平; 我妻 慧; 細貝 良行, 国際医療福祉大学学会誌, 23, 抄録号, 25, 25, 2018
国際医療福祉大学学会, Japanese

Accuracy of Standardized Uptake Values Obtained by Quantitative PET/CT and SPECT/CT
三輪建太; 高橋裕人; 宮司典明; 我妻慧; 村田泰輔, 医学物理, 38, 2, 79, 84, 2018
(公社)日本医学物理学会, Japanese

核医学的手法を用いた無採血150標識ガス検査による脳循環代謝計測法の開発
三輪建太; 我妻慧; 細貝良行, 国際医療福祉大学学会誌, 22, 抄録号, 24, 24, 2018
国際医療福祉大学学会, Japanese

テクスチャー解析ソフトウェアの違いがPET画像の特徴量に与える影響
成瀬正理; 三輪建太; 上石愛佳; 工藤唯子; MULADILI Tusongjiang; 上高祐人; 菅満喜人; 我妻慧, 核医学技術, 38, 予稿集, 413, 413, 2018
(NPO)日本核医学技術学会, Japanese

4種類の異なるPET/CT装置におけるBayesian Penalized Likelihood(BPL)法と3D‐OSEM法の比較
宮司典明; 宮司典明; 我妻慧; 茂木一樹; 茂木一樹; 梅田拓朗; 深井翔平; 島田直毅; 三輪建太; 小野口昌久; 寺内隆司; 小泉満, 核医学技術, 38, 予稿集, 405, 405, 2018
(NPO)日本核医学技術学会, Japanese

¹⁸F‐NaF骨PETにおける短時間撮像のための至適画像再構成条件の検討
山口将司; 三輪建太; 我妻慧; 根本玲央; 高橋裕人; 横川光, 核医学技術, 38, 予稿集, 461, 461, 2018
(NPO)日本核医学技術学会, Japanese

虚血性脳血管障害症例における有酸素運動に伴う脳循環応答の検討 15O-H2Oを用いたPET研究の知見から
日浦 幹夫; 成相 直; 牟田 光孝; 豊原 潤; 石井 賢二; 石橋 賢士; 坂田 宗之; 我妻 慧; 多胡 哲朗; 前原 健寿, 脳循環代謝, 29, 1, 181, 181, Nov. 2017
日本脳循環代謝学会, Japanese

新しいSiPM-Based TOF-PET/CT装置によるサブセンチ微小球の検出能の評価
増渕 正輝; 我妻 慧; 小野 遥香; 根本 玲央; 木村 周平; 三輪 建太, 日本放射線技術学会雑誌, 73, 9, 894, 894, Sep. 2017
(公社)日本放射線技術学会, Japanese

膀胱付近の病変におけるTime-of-Flight PETによる定量評価の改善 A Phantom Study
冨田 陽也; 我妻 慧; 市川 泰崇; 牧 浩昭; 佐久間 肇, 日本放射線技術学会雑誌, 73, 9, 894, 895, Sep. 2017
(公社)日本放射線技術学会, Japanese

トレーサブル点状線源を用いる定量性評価校正法の開発状況報告
長谷川 智之; 小山 翔司; 宮武 比呂樹; 菊池 敬; 井上 優介; 佐藤 泰; 我妻 慧; 織田 圭一; 和田 康弘; 三輪 健太, 核医学, 54, Suppl., S169, S169, Sep. 2017
(一社)日本核医学会, Japanese

Amyloid PETとVBMによる内側側頭葉萎縮検出の比較
亀山 征史; 石橋 賢士; 櫻井 圭太; 豊原 潤; 我妻 慧; 坂田 宗之; 亀山 祐美; 下地 啓五; 多胡 哲郎; 金丸 和富; 村山 繁雄; 徳丸 阿耶; 石井 賢二, 核医学, 54, Suppl., S205, S205, Sep. 2017
(一社)日本核医学会, Japanese

11C-ITMM PETを用いた未治療パーキンソン病におけるmGluR1密度と症状との関係
三品 雅洋; 鈴木 正彦; 石井 賢二; 石橋 賢士; 坂田 宗之; 我妻 慧; 豊原 潤; 張 明栄; 木村 和美; 石渡 喜一; 東京都健康長寿医療センター研究所神経画像研究チーム, 核医学, 54, Suppl., S206, S206, Sep. 2017
(一社)日本核医学会, Japanese

機械学習を用いた認知症自動鑑別におけるFDG画像とMR画像の比較
坂田 宗之; 王 小宇; 石井 賢二; 木村 裕一; 我妻 慧; 石橋 賢士; 豊原 潤; 矢田 紀子; 眞鍋 佳嗣, 核医学, 54, Suppl., S187, S187, Sep. 2017
(一社)日本核医学会, Japanese

虚血性脳血管障害の患者群における運動負荷に対する脳血流変化の特徴 H215Oを用いたPET研究
日浦 幹夫; 成相 直; 牟田 光孝; 坂田 宗之; 我妻 慧; 多胡 哲郎; 石橋 賢士; 豊原 潤; 石井 賢二; 東京都健康長寿医療センター神経画像研究チーム, 核医学, 54, Suppl., S177, S177, Sep. 2017
(一社)日本核医学会, Japanese

神経画像最前線 PETイメージングを活用した運動負荷時の脳機能解析 脳血流量と神経受容体計測の実際
日浦 幹夫; 成相 直; 牟田 光孝; 稲次 基希; 豊原 潤; 石井 賢二; 石橋 賢士; 我妻 慧; 坂田 宗之; 織田 圭一; 石渡 喜一; 前原 健寿, 脳循環代謝, 28, 2, 297, 302, Aug. 2017
(一社)日本脳循環代謝学会, Japanese

Validation study of new cross calibration method using NIST traceable Ge-68/Ga-68 source kit
Kei Wagatsuma; Muneyuki Sakata; Keiichi Oda; Masayuki Sasaki; Kenji Ishii, JOURNAL OF NUCLEAR MEDICINE, 58, May 2017
English, Summary international conference

Comparison of FDG-PET Image and MR Image in differential dementia diagnosis using machine lerning
WANG Xiaoyu; WANG Xiaoyu; 坂田宗之; 石井賢二; 木村裕一; 木村裕一; 我妻慧; 石橋賢士; 豊原潤; 矢田紀子; 眞鍋佳嗣, 電子情報通信学会技術研究報告, 116, 393(MI2016 71-121), 2017

海馬硬化症を伴う内側側頭葉てんかん患者におけるmGluR subtype1PETイメージング
稲次基希; 稲次基希; 橋本聡華; 林志保里; 林志保里; 我妻慧; 豊原潤; 石井賢二; 前原健寿, 日本てんかん外科学会プログラム・抄録集, 40th, 2017

PET imaging for altered brain function evoked by exercise: measurements of changes in cerebral blood flow and neurotransmitters
日浦幹夫; 日浦幹夫; 日浦幹夫; 成相直; 成相直; 牟田光孝; 稲次基希; 稲次基希; 豊原潤; 石井賢二; 石橋賢士; 我妻慧; 坂田宗之; 織田圭一; 織田圭一; 石渡喜一; 石渡喜一; 石渡喜一; 前原健寿, 脳循環代謝(Web), 28, 2, 297, 302, 2017
(一社)日本脳循環代謝学会, Japanese

虚血性脳血管障害症例における有酸素運動に伴う脳循環応答の検討:¹⁵O-H₂Oを用いたPET研究の知見から
日浦幹夫; 成相直; 成相直; 牟田光孝; 豊原潤; 石井賢二; 石橋賢士; 坂田宗之; 我妻慧; 多胡哲朗; 前原健寿, 脳循環代謝(Web), 29, 1, 2017

虚血性脳血管障害の患者群における運動負荷に対する脳血流変化の特性:H₂¹⁵Oを用いたPET研究
日浦幹夫; 日浦幹夫; 成相直; 成相直; 牟田光孝; 坂田宗之; 我妻慧; 多胡哲郎; 石橋賢士; 豊原潤; 石井賢二, 核医学(Web), 54, Supplement, 2017

Amyloid PETとVBMによる内側側頭葉萎縮検出の比較
亀山征史; 石橋賢士; 櫻井圭太; 豊原潤; 我妻慧; 坂田宗之; 亀山祐美; 下地啓五; 多胡哲郎; 金丸和富; 村山繁雄; 村山繁雄; 徳丸阿耶; 石井賢二, 核医学(Web), 54, Supplement, 2017

機械学習を用いた認知症自動鑑別におけるFDG画像とMR画像の比較
坂田宗之; 王小宇; 王小宇; 石井賢二; 木村裕一; 木村裕一; 我妻慧; 石橋賢士; 豊原潤; 矢田紀子; 眞鍋佳嗣, 核医学(Web), 54, Supplement, 2017

トレサーブル点状線源を用いる定量性評価校正法の開発状況報告
長谷川智之; 小山翔司; 宮武比呂樹; 菊池敬; 井上優介; 佐藤泰; 我妻慧; 織田圭一; 和田康弘; 三輪健太, 核医学(Web), 54, Supplement, 2017

¹¹C-ITMM PETを用いた未治療パーキンソン病におけるmGluR1密度と症状との関係
三品雅洋; 三品雅洋; 三品雅洋; 鈴木正彦; 鈴木正彦; 石井賢二; 石橋賢士; 坂田宗之; 我妻慧; 豊原潤; 張明栄; 木村和美; 石渡喜一; 石渡喜一; 石渡喜一, 核医学(Web), 54, Supplement, 2017

Ra-223イメージングにおける異なるコリメータを用いた総合感度と総合空間分解能の比較
梅田拓朗; 宮司典明; 中澤脩人; 茂木一樹; 我妻慧; 三輪健太; 小泉満, 日本放射線技術学会総会学術大会予稿集, 73rd, 140, 140, 2017
(公社)日本放射線技術学会, Japanese

Quantitative Assessment in Amyloid-PET Imaging
三輪建太; 三輪建太; 三輪建太; 我妻慧; 山尾天翔; 上高祐人; 松原佳亮; 赤松剛; 今林悦子, 日本放射線技術学会雑誌, 73, 11, 1165, 1174, 2017
(公社)日本放射線技術学会, Japanese

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
(NPO)日本核医学技術学会, Japanese

¹¹C‐PiBアミロイドPETに対するCentiloid scaleの機種依存性の検討
平塚勢哉; 木村周平; 我妻慧; 増渕正輝; 上高祐人; 三輪建太, 核医学技術, 37, 予稿集, 462, 462, 2017
(NPO)日本核医学技術学会, Japanese

新しいSiPM‐based TOF‐PET装置と従来のPMT‐based TOF‐PET装置の性能比較
小野遥香; 我妻慧; 増渕正輝; 根本玲央; 小野貴史; 伊藤希; 山口正太郎; 三輪建太, 核医学技術, 37, 予稿集, 466, 466, 2017
(NPO)日本核医学技術学会, Japanese

SiPM‐PET/CT装置における脳FDG検査の最適画像再構成条件の決定
我妻慧; 坂田宗之; 三輪建太; 石橋賢士; 石井賢二, 核医学技術, 37, 予稿集, 462, 462, 2017
(NPO)日本核医学技術学会, Japanese

脳PETに対するpenalized likelihood reconstruction法の至適β値の検討
上高祐人; 我妻慧; 小池笑也; 平塚勢哉; 南本亮吾; 石井賢二; 三輪建太, 核医学技術, 37, 予稿集, 462, 462, 2017
(NPO)日本核医学技術学会, Japanese

内側側頭葉てんかん患者のmGluR1 PET imaging
橋本 聡華; 稲次 基希; 林 志保里; 我妻 慧; 豊原 潤; 石井 賢二; 前原 健寿, 脳循環代謝, 28, 1, 201, 201, Nov. 2016
日本脳循環代謝学会, Japanese

神経画像最前線 神経機能の可視化はどこまで進んだか PETイメージングを活用した運動負荷時の脳機能解析 脳血流量と神経受容体計測の実際
日浦 幹夫; 成相 直; 牟田 光孝; 稲次 基希; 豊原 潤; 石井 賢二; 石橋 賢士; 我妻 慧; 坂田 宗之; 織田 圭一; 石渡 喜一; 前原 健寿, 脳循環代謝, 28, 1, 134, 134, Nov. 2016
日本脳循環代謝学会, Japanese

認知症被検者の医療安全 診療放射線技師の立場から
我妻 慧, 核医学, 53, Suppl., S204, S204, Oct. 2016
(一社)日本核医学会, Japanese

新規アデノシンA2A受容体イメージング剤11C-Preladenantの初期臨床評価
豊原 潤; 坂田 宗之; 石橋 賢士; 我妻 慧; 周 小云; ドフリース・エリク; エルシンガ・フィリップ; 石渡 喜一; 石井 賢二, 核医学, 53, Suppl., S263, S263, Oct. 2016
(一社)日本核医学会, Japanese

[C-11]ITMM PETを用いた未治療パーキンソン病における代謝型グルタミン酸受容体1型密度の検討(第一報)
三品 雅洋; 鈴木 正彦; 石井 賢二; 坂田 宗之; 我妻 慧; 石橋 賢士; 豊原 潤; 張 明栄; 木村 和美; 石渡 喜一, 核医学, 53, Suppl., S286, S286, Oct. 2016
(一社)日本核医学会, Japanese

トレーサブル点状線源を用いる定量性評価校正法
長谷川 智之; 小山 翔司; 宮武 比呂樹; 菊池 敬; 井上 優介; 佐藤 泰; 我妻 慧; 織田 圭一; 和田 康弘; 三輪 健太; 村田 泰輔, 核医学, 53, Suppl., S307, S307, Oct. 2016
(一社)日本核医学会, Japanese

脳FDG画像を用いた認知症鑑別診断における機械学習から得られる画像指標と認知機能との関係
坂田 宗之; 王 小宇; 石井 賢二; 木村 裕一; 我妻 慧; 石橋 賢士; 豊原 潤; 矢田 紀子; 眞鍋 佳嗣, 核医学, 53, Suppl., S278, S278, Oct. 2016
(一社)日本核医学会, Japanese

次世代の核医学イメージング剤 臨床応用を目指したPET薬剤の次世代化
豊原 潤; 多胡 哲郎; 坂田 宗之; 石橋 賢士; 我妻 慧; 石渡 喜一; 石井 賢二, 核医学, 53, Suppl., S158, S158, Oct. 2016
(一社)日本核医学会, Japanese

新規TSPOイメージング剤11C-CB184の初期臨床評価
豊原 潤; 坂田 宗之; 石橋 賢士; 我妻 慧; 籏野 健太郎; 石渡 喜一; 石井 賢二, 核医学, 53, Suppl., S263, S263, Oct. 2016
(一社)日本核医学会, Japanese

PETイメージングを活用した運動負荷時の脳機能解析:脳血流量と神経受容体計測の実際
日浦幹夫; 日浦幹夫; 日浦幹夫; 成相直; 牟田光孝; 牟田光孝; 稲次基希; 豊原潤; 石井賢二; 石橋賢士; 我妻慧; 坂田宗之; 織田圭一; 石渡喜一; 石渡喜一; 前原健寿, 脳循環代謝(Web), 28, 1, 2016

内側側頭葉てんかん患者のmGluR1PET imaging
橋本聡華; 橋本聡華; 稲次基希; 稲次基希; 林志保里; 林志保里; 我妻慧; 豊原潤; 石井賢二; 前原健寿, 脳循環代謝(Web), 28, 1, 2016

臨床応用を目指したPET薬剤の次世代化
豊原潤; 多胡哲郎; 坂田宗之; 石橋賢士; 我妻慧; 石渡喜一; 石渡喜一; 石渡喜一; 石井賢二, 核医学(Web), 53, Supplement, 2016

新規TSPOイメージング剤¹¹C-CB184の初期臨床評価
豊原潤; 坂田宗之; 石橋賢士; 我妻慧; 籏野健太郎; 石渡喜一; 石渡喜一; 石渡喜一; 石井賢二, 核医学(Web), 53, Supplement, 2016

新規アデノシンA_2A受容体イメージング剤¹¹C-Preladenantの初期臨床評価
豊原潤; 坂田宗之; 石橋賢士; 我妻慧; 周小云; ドフリース エリク; エルシンガ フィリップ; 石渡喜一; 石渡喜一; 石渡喜一; 石井賢二, 核医学(Web), 53, Supplement, 2016

[C-11]ITMM PETを用いた未治療パーキンソン病における代謝型グルタミン酸受容体1型密度の検討-第一報-
三品雅洋; 三品雅洋; 三品雅洋; 三品雅洋; 鈴木正彦; 鈴木正彦; 石井賢二; 坂田宗之; 我妻慧; 石橋賢士; 豊原潤; 張明栄; 木村和美; 木村和美; 木村和美; 石渡喜一, 核医学(Web), 53, Supplement, 2016

認知症被検者の医療安全~診療放射線技師の立場から~
我妻慧, 核医学(Web), 53, Supplement, 2016

脳FDG画像を用いた認知症鑑別診断における機械学習から得られる画像指標と認知機能との関係
坂田宗之; 王小宇; 王小宇; 石井賢二; 木村裕一; 木村裕一; 我妻慧; 石橋賢士; 豊原潤; 矢田紀子; 眞鍋佳嗣, 核医学(Web), 53, Supplement, 2016

トレーサブル点状線源を用いる定量性評価校正法
長谷川智之; 小山翔司; 宮武比呂樹; 菊池敬; 井上優介; 佐藤泰; 我妻慧; 織田圭一; 和田康弘; 三輪健太; 村田泰輔, 核医学(Web), 53, Supplement, 2016

トレーサブルGe-68/Ga-68点状線源に関わる位置依存性の基本的評価
小山翔司; 長谷川智之; 坂口和也; 菊池敬; 宮武比呂樹; 井上優介; 我妻慧; 織田圭一, 日本放射線技術学会雑誌, 72, 9, 826, 827, 2016
(公社)日本放射線技術学会, Japanese

当日検定塩化タリウムにおける心筋SPECTの最適撮像条件の検討
内藤洋俊; 笹間雄樹; 我妻慧; 工藤善朗; 海野泰; 波多野嗣久, 核医学技術, 36, 予稿集, 446, 446, 2016
(NPO)日本核医学技術学会, Japanese

血糖値上昇による脳内ブドウ糖代謝能の変化
石橋 賢士; 我妻 慧; 石渡 喜一; 石井 賢二, 臨床神経学, 57th, Suppl., S474, S474, 2016
(一社)日本神経学会, Japanese

D-16-6 Relationship between image and clinical indicators in differential dementia diagnosis using FDG-PET image
Wang Xiaoyu; Sakata Muneyuki; Ishii Kenji; Kimura Yuichi; Wagatsuma Kei; Ishibashi Kenji; Toyohara Jun; Yata Noriko; Manabe Yoshitugu, Proceedings of the IEICE General Conference, 2016, 2, 2016
The Institute of Electronics, Information and Communication Engineers, Japanese

Block Sequential Regularized Expectation Maximization法によるベイズ型画像再構成のエッジアーチファクトの改善効果
山口 正太郎; 我妻 慧; 三輪 建太; 石井 賢二; 井上 一雅; 福士 政広, 日本放射線技術学会雑誌, 72, 9, 878, 878, 2016
(公社)日本放射線技術学会, Japanese

表示付認証機器の使用に関する国内動向とその対応
我妻慧; 我妻慧; 對馬博之; 三輪建太, 核医学技術, 36, 1, 94, 97, 2016
(NPO)日本核医学技術学会, Japanese

PET校正用⁶⁸Ge/⁶⁸Ga線源キットを用いた相互校正の妥当性
我妻慧; 三輪建太; 坂田宗之; 織田圭一; 織田圭一; 石井賢二, 核医学技術, 36, 予稿集, 451, 451, 2016
(NPO)日本核医学技術学会, Japanese

NISTトレーサブル標準線源を用いた多施設PET装置のSUV精度管理
三輪建太; 我妻慧; 宮司典明; 神谷貴史; 飯森隆志; 澤田晃一; 櫻井実, 核医学技術, 36, 予稿集, 452, 452, 2016
(NPO)日本核医学技術学会, Japanese

表示付認証機器の使用に関する国内動向とその対応 表示付認証機器の適正使用に関するWG
我妻 慧, 核医学技術, 35, 予稿集, 316, 316, Sep. 2015
(NPO)日本核医学技術学会, Japanese

Differential alteration of neuronal network with FDG-PET in Alzheimer's disease and dementia with Lewy bodies
Masamichi Imai; Mika Tanaka; Kenji Ishibashi; Kei Wagatsuma; Muneyuki Sakata; Jun Toyohara; Hirotaka Maruno; Kenji Ishii, JOURNAL OF NUCLEAR MEDICINE, 56, 3, May 2015
English, Summary international conference

代謝型グルタミン酸受容体タイプ1の加齢変化 [11C]ITMM-PETを用いた検討
坂田 宗之; 豊原 潤; 我妻 慧; 石橋 賢士; 石井 賢二; 張 明栄; 石渡 喜一, 日本老年医学会雑誌, 52, Suppl., 157, 157, May 2015
(一社)日本老年医学会, Japanese

肝臓病変に対する非線形画像処理を用いた位相呼吸同期PET/CT撮像の有用性
大澤達史; 我妻慧; 横川直樹; 鈴木諭貴; 工藤善朗; 海野泰; 伊藤公輝, 日本放射線技術学会総会学術大会予稿集, 71st, 210, 210, 2015
(公社)日本放射線技術学会, Japanese

CT-AECを用いたPET撮像プロトコルの検討
横川直樹; 我妻慧; 鈴木諭貴; 大澤達史; 工藤善朗; 海野泰; 伊藤公輝, 日本放射線技術学会総会学術大会予稿集, 71st, 210, 210, 2015
(公社)日本放射線技術学会, Japanese

Technical Approaches for Quantitative Treatment Responses Using ¹⁸F-FDG PET
三輪建太; 三輪建太; 宮司典明; 梅田拓朗; 村田泰輔; 我妻慧; 佐々木雅之, 医学物理, 35, 1, 30, 38, 2015
(公社)日本医学物理学会, Japanese

代謝型グルタミン酸受容体タイプ1の加齢変化 [11C]ITMM-PETを用いた検討
坂田 宗之; 豊原 潤; 我妻 慧; 石橋 賢士; 石井 賢二; 張 明栄; 石渡 喜一, 基礎老化研究, 39, 2, 67, 67, 2015
日本基礎老化学会, Japanese

脳FDG画像を用いた認知症鑑別診断における機械学習の可用性の検討
坂田 宗之; 王 小宇; 石井 賢二; 木村 裕一; 我妻 慧; 石橋 賢士; 豊原 潤; 矢田 紀子; 石渡 喜一; 眞鍋 佳嗣, 核医学, 52, 3, 278, 278, 2015
(一社)日本核医学会, Japanese

D-16-6 A feasibility study of machine learning for differential dementia diagnosis using FDG-PET images
Wang Xiaoyu; Sakata Muneyuki; Ishii Kenji; Kimura Yuichi; Wagatsuma Kei; Ishibashi Kenji; Toyohara Jun; Yata Noriko; Ishiwata Kiichi; Manabe Yoshitugu, Proceedings of the IEICE General Conference, 2015, 2, 2015
The Institute of Electronics, Information and Communication Engineers, Japanese

[¹¹C]ITMMによる代謝型グルタミン酸受容体タイプ1結合能の加齢変化
坂田宗之; 豊原潤; 我妻慧; 石橋賢士; 石井賢二; 張明栄; 石渡喜一, 核医学, 52, 3, 264, 264, 2015
(一社)日本核医学会, Japanese

PET用自動投与装置3機種における精度評価
宮司典明; 三輪建太; 村田泰輔; 我妻慧; 梅田拓朗; 滝口智洋, 日本放射線技術学会総会学術大会予稿集, 71st, 215, 216, 2015
(公社)日本放射線技術学会, Japanese

トレーサブル22Na点状線源を用いたPET空間分解能補正の位置依存性の評価
村田泰輔; 三輪建太; 宮司典明; 我妻慧; 長谷川智之; 織田圭一; 滝口智洋, 日本放射線技術学会総会学術大会予稿集, 71st, 167, 167, 2015
(公社)日本放射線技術学会, Japanese

Technical advancement in oncological PET/CT imaging: impact of point-spread function and time-of-flight
三輪建太; 三輪建太; 赤松剛; 赤松剛; 村田泰輔; 梅田拓朗; 我妻慧; 宮司典明; 佐々木雅之, 臨床放射線, 60, 6, 787, 795, 2015
金原出版(株), Japanese

班報告:FDG‐PETとMRIにおけるSUVとADCの定量性に関する多施設共同研究
三輪建太; 我妻慧; 飯森隆志; 澤田晃一; 神谷貴史; 福澤圭; 佐藤英介, 日本放射線技術学会雑誌, 71, 9, 827, 827, 2015
(公社)日本放射線技術学会, Japanese

アミノ酸PETにおける脳腫瘍模擬ファントムの腫瘍バックグラウンド比および輪郭抽出に関する研究
我妻慧; 我妻慧; 三輪建太; 横川直樹; 大澤達史; 織田圭一; 織田圭一; 石井賢二; 石渡喜一; 佐々木雅之, 核医学技術, 35, 予稿集, 363, 363, 2015
(NPO)日本核医学技術学会, Japanese

[¹¹C]PE2Iの静態計測における至適計測時間の検討
坂田宗之; 石井賢二; 石橋賢士; 我妻慧; 織田圭一; 織田圭一; 豊原潤; 石渡喜一, 核医学, 51, 3, 313, 313, 2014
(一社)日本核医学会, Japanese

三次元PET脳循環代謝測定における体幹部シールドの効果
織田 圭一; 我妻 慧; 稲次 基樹; 林 志保里; 成相 直; 坂田 宗之; 石井 賢二; 叶井 徹; 今林 悦子; 豊原 潤; 石渡 喜一, 核医学, 51, 3, 312, 312, 2014
(一社)日本核医学会, Japanese

PET/CTを使用したMIRD法による実行線量評価
伊藤 公輝; 坂田 宗之; 我妻 慧; 織田 圭一; 豊原 潤; 石橋 賢士; 石井 賢二; 石渡 喜一, 核医学, 51, 3, 324, 324, 2014
(一社)日本核医学会, Japanese

新しい固有同期法を用いた小動物用CTによる左室機能評価
犬伏正幸; 三輪建太; 青木伊知男; 辻厚至; 竹内康人; 我妻慧; 村田泰輔; 宮原信幸; 佐賀恒夫; 小泉満; 佐々木雅之, JSMI Rep, 7, 2, 75, 75, 2014
日本分子イメージング学会, Japanese

新しい固有同期法を用いた小動物用CTによる左室機能評価
犬伏正幸; 三輪建太; 青木伊知男; 辻厚至; 竹内康人; 我妻慧; 村田泰輔; 宮原信幸; 佐賀恒夫; 小泉満; 佐々木雅之, JSMI Rep, 7, 2, 168, 75, 2014
日本分子イメージング学会, Japanese

呼吸同期PET/CTの技術的検討と4次元放射線治療計画に向けて
三輪建太; 我妻慧; 村田泰輔, PET J, 26, 10, 12, 2014
先端医療技術研究所, Japanese

位相呼吸同期PET/CT撮像によるPET定量値の改善率の検討
梅田拓朗; 三輪建太; 我妻慧; 村田泰輔; 宮司典明; 大澤敦; 滝口智洋; 小泉満, 日本放射線技術学会雑誌, 70, 9, 1029, 1029, 2014
(公社)日本放射線技術学会, Japanese

O‐15ガスPET/CT撮像におけるコールドアーチファクト改善の検討
我妻慧; 織田圭一; 三輪建太; 稲次基希; 林志保里; 石井賢二; 坂田宗之; 石橋賢士; 伊藤公輝; 豊原潤; 成相直; 石渡喜一, 核医学技術, 34, 予稿集, 337, 337, 2014
(NPO)日本核医学技術学会, Japanese

FDG‐PET/CTの呼吸制御に関する研究
三輪建太; 赤松剛; 筒井悠治; 光元勝彦; 坂口裕一; 我妻慧; 佐々木雅之, 日本放射線技術学会雑誌, 70, 11, 1344, 1352, 2014
(公社)日本放射線技術学会, Japanese

表示付認証機器⁵⁷Co面線源の安全取扱いに関するガイドライン
金谷信一; 秋本健太; 奥山康男; 對間博之; 三輪建太; 我妻慧; 大屋信義; 小野口昌久; 飛坂実; 野村悦司; 池谷憲生; 菊池香織; 黒野康生; 藤埜浩一, 核医学技術, 34, 4, 405, 439, 2014
(NPO)日本核医学技術学会, Japanese

モンテカルロ計算を用いた高エネルギーβ線放出核種に対する最適な遮蔽材の検討
村田泰輔; 三輪健太; 松林史泰; 我妻慧; 秋本健太; 藤淵俊王; 小泉満, 日本放射線技術学会総会学術大会予稿集, 69th, 208, 208, 2013
(公社)日本放射線技術学会, Japanese

腕の動きによる散乱補正エラーに対する補正アルゴリズムの精度
梅田拓朗; 三輪建太; 我妻慧; 村田泰輔; 宮司典明; 大澤敦; 滝口智洋; 小泉満, 日本放射線技術学会雑誌, 69, 9, 1014, 1014, 2013
(公社)日本放射線技術学会, Japanese

実測とDICOM image headerによるscatter fractionの比較
大澤敦; 三輪建太; 秋本健太; 我妻慧; 内田茂樹; 鍵小野祐基; 富岡和彦; 滝口智洋, 日本放射線技術学会雑誌, 69, 9, 1015, 1015, 2013
(公社)日本放射線技術学会, Japanese

四肢末梢骨転移のFDG‐PET
小山眞道; 小泉満; 三輪建太; 我妻慧, 核医学, 50, 3, S234, S234, 2013
(一社)日本核医学会, Japanese

肺結節病変の¹⁸FDG集積分布の不均一性による良悪性鑑別
三輪建太; 我妻慧; 大澤敦; 小山眞道; 早坂和正; 長尾充展; 佐々木雅之, 日本放射線技術学会総会学術大会予稿集, 68th, 181, 182, 2012
(公社)日本放射線技術学会, Japanese

骨シンチグラフィ自動解析ソフトの小児悪性骨腫瘍への利用
我妻慧; 三輪建太; 菊池明泰; 大澤敦; 秋本健太; 滝口智洋; 小山眞道, 日本放射線技術学会総会学術大会予稿集, 68th, 146, 146, 2012
(公社)日本放射線技術学会, Japanese

散乱補正精度の被写体直径依存性に関する実測評価
大澤敦; 三輪建太; 秋本健太; 我妻慧; 滝口智洋, 日本放射線技術学会雑誌, 68, 9, 1214, 1215, 2012
(公社)日本放射線技術学会, Japanese

トレーサブルNIST標準線源を用いたPET用ドーズキャリブレータの性能評価
宮司典明; 三輪建太; 我妻慧; 大澤敦; 滝口智洋; 小泉満, 核医学技術, 32, 予稿集, 291, 291, 2012
(NPO)日本核医学技術学会, Japanese

骨シンチ診断支援ソフトにおけるMorphonセグメンテーションの精度
三輪 建太; 我妻 慧; 秋本 健太; 菊池 明泰; 小山 眞道; 犬伏 正幸; 早坂 和正; 滝口 智洋; 大澤 敦; 佐々木 雅之, 核医学技術, 31, 予稿集, 315, 315, Sep. 2011
(NPO)日本核医学技術学会, Japanese

57Co面線源を用いたガンマカメラ総合均一性試験の最適収集条件の検討
秋本 健太; 三輪 建太; 我妻 慧; 滝口 智洋; 大澤 敦; 田村 慎太郎; 山田 康彦; 小山 眞道; 早坂 和正, 核医学技術, 31, 予稿集, 336, 336, Sep. 2011
(NPO)日本核医学技術学会, Japanese

ガンマカメラ校正用57Co面線源の使用経験と有用性について
秋本 健太; 三輪 建太; 我妻 慧; 滝口 智洋; 大澤 敦; 田村 慎太郎; 山田 康彦; 小山 眞道; 早坂 和正, 核医学技術, 31, 予稿集, 336, 336, Sep. 2011
(NPO)日本核医学技術学会, Japanese

腫瘍の代謝変化に基づく治療効果判定基準PERCISTの検証
三輪建太; 我妻慧; 大澤敦; 滝口智洋; 梅田徳男; 小島礼慎; 犬伏正幸, 日本放射線技術学会総会学術大会予稿集, 67th, 322, 322, 2011
(公社)日本放射線技術学会, Japanese

被検者体格の違いによる計数率特性がPET画像に与える影響
我妻慧; 大澤敦; 三輪建太; 滝口智洋; 田村慎太郎; 秋本健太; 早坂和正, 日本放射線技術学会総会学術大会予稿集, 67th, 250, 251, 2011
(公社)日本放射線技術学会, Japanese

異なる被写体断面積の散乱ファントムによるScatter Fractionの測定
大澤敦; 三輪建太; 我妻慧; 滝口智洋; 田村慎太郎; 秋本健太; 内田茂樹, 日本放射線技術学会雑誌, 67, 9, 1079, 1079, 2011
(公社)日本放射線技術学会, Japanese

フラクタル次元を用いた肺癌と炎症性疾患の鑑別
三輪建太; 我妻慧; 小山眞道; 犬伏正幸; 佐賀恒夫; 長尾充展; 佐々木雅之, 核医学, 48, 3, S263, S263, 2011
(一社)日本核医学会, Japanese

フラクタル解析を用いた骨シンチグラフィ臨床診断補助の検討
我妻慧; 三輪建太; 小山眞道; 早坂和正; 長尾充展; 高橋由武, 核医学, 48, 3, S234, S234, 2011
(一社)日本核医学会, Japanese

IgG4関連疾患の診断におけるFDG‐PET
小山眞道; 田中宏子; 三輪建太; 我妻慧; 田村慎太郎; 早坂和正, 核医学, 48, 3, S257, S257, 2011
(一社)日本核医学会, Japanese

放射性廃棄物に関する放射線管理システムの構築
秋本健太; 三輪建太; 我妻慧; 山田康彦, 日本放射線安全管理学会学術大会講演予稿集, 10th, 69, 2011
Japanese

超大型pool phantomによるPET/CT臨床画像の再現―薬剤投与量・被写体断面積とNEC_phantom・Q_H,10mm・N_10mm―
大澤敦; 滝口智洋; 田村慎太郎; 三輪建太; 秋本健太; 我妻慧; 小山眞道; 早坂和正, 日本放射線技術学会雑誌, 66, 9, 1135, 1135, 2010
(公社)日本放射線技術学会, Japanese

薬剤供給システムの異なるFDG PET/CT検査における臨床画像の比較検討
我妻慧; 三輪建太; 田村慎太郎; 大澤敦; 滝口智洋; 秋本健太, 日本放射線技術学会雑誌, 66, 9, 1134, 1135, 2010
(公社)日本放射線技術学会, Japanese

超大型pool phantomによるPET/CT臨床画像の再現―被写体断面積が極端に大きい場合の考察―
大澤敦; 滝口智洋; 田村慎太郎; 三輪建太; 秋本健太; 我妻慧; 小山眞道; 早坂和正, 日本放射線技術学会雑誌, 66, 9, 1135, 1135, 2010
(公社)日本放射線技術学会, Japanese

メトトレキサート関連リンパ増殖性疾患のFDG‐PET
小山眞道; 早坂和正; 大澤敦; 田村慎太郎; 三輪建太; 秋本健太; 我妻慧; 内田茂樹, 核医学, 47, 3, S263-S264, 418, 2010
(一社)日本核医学会, Japanese

FDG‐PET/CTを用いた補正Standardized uptake valueによる悪性リンパ腫の定量的治療効果判定
三輪建太; 田村慎太郎; 我妻慧; 小山眞道; 早坂和正, 核医学, 47, 3, S263, 417, 2010
(一社)日本核医学会, Japanese

PET‐CTで横隔膜周辺に発生するアーチファクトの再現‐動体ファントムによるEmissionの検討‐
大澤敦; 滝口智洋; 田村慎太郎; 北村望; 大橋聖; 三輪建太; 秋本健太; 我妻慧, 日本放射線技術学会雑誌, 65, 9, 1231, 1231, 2009
(公社)日本放射線技術学会, Japanese

PET‐CTで横隔膜周辺に発生するアーチファクトの再現‐動体ファントムによるCT‐Transmissionの検討‐
大澤敦; 滝口智洋; 田村慎太郎; 北村望; 大橋聖; 三輪建太; 秋本健太; 我妻慧, 日本放射線技術学会雑誌, 65, 9, 1231, 1231, 2009
(公社)日本放射線技術学会, Japanese

放射線医療技術叢書（38）アーチファクト・アトラス（MRI，CT，SPECT，PET）
三輪建太; 我妻慧; 越智伸司; 孫田恵一; 村田泰輔, 第4章 PET画像に発生するアーチファクト
日本放射線技術学会出版委員会, Mar. 2021, [Contributor]

新核医学技術総論[臨床編]
日本核医学技術学会, 第2節 糖代謝イメージング，第3章 PET検査，第Ⅱ部 脳神経
山代印刷出版部, Mar. 2020, 9784991020124, 2冊, Japanese, [Contributor]

新核医学技術総論[技術編]
日本核医学技術学会, 第2章 PET装置，第Ⅲ部 装置の性能評価と安全実施上の保守点検
山代印刷出版部, Mar. 2020, 9784991020124, 2冊, Japanese, [Contributor]

超実践マニュアル核医学
VERSUS研究会; 對間, 博之; 飯森, 隆志; 甲谷, 理温, I-10 PET 脳
医療科学社, Apr. 2016, 9784860034771, xix, 488p, Japanese

初学者のための核医学実験入門 = ABC book of experiment in nuclear medicine for beginners
日本放射線技術学会核医学部会, 3.5 脳PET撮像実験
日本放射線技術学会出版委員会, 2016, [Contributor]

認知症PET技術 up-to-date
我妻慧
第82回札幌核医学技術研究会, 28 Nov. 2025, Japanese, Invited oral presentation

Technical Developments in Tau PET for Dementia Research
Kei Wagatsuma
The 28th Hokkaido University-Seoul National University Joint Symposium, 18 Nov. 2025, Japanese, Nominated symposium
18 Nov. 2025 - 18 Nov. 2025

マルチモダリティ 核医学
我妻慧
医学物理士会 2025年度ベーシックセミナー④, Oct. 2025, Japanese, Public discourse
24 Oct. 2025 - 13 Nov. 2025

体の機能を視る核医学検査ってなんだろう？
我妻慧
北海道大学大学院保健科学研究院 公開講座, 03 Nov. 2025, Japanese, Public discourse

PET核医学エキスパートセミナー 基礎1 PET装置のQA/QC
我妻慧
第25回日本核医学会春季大会, Apr. 2025, Japanese, Public discourse
24 Apr. 2025 - 03 Jun. 2025

PET研修セミナー 臨床PET検査法 PET画像処理
我妻慧
第25回日本核医学会春季大会, Apr. 2025, Japanese, Public discourse
24 Apr. 2025 - 03 Jun. 2025

認知症PET検査と核医学技術
我妻慧
日本診療放射線技師連盟主催 第9回定例勉強会, 23 Apr. 2025, Japanese, Invited oral presentation
23 Apr. 2025 - 23 Apr. 2025, [Invited]

一歩先のアミロイドPET画像の作り方
我妻慧
第28回Neurology SPECT定量検討会, 16 Nov. 2024, Japanese, Keynote oral presentation
[Invited]

アミロイドPET検査の撮像技術
我妻慧
第1回日本放射線医療技術大会, 01 Nov. 2024, Japanese, Keynote oral presentation
31 Oct. 2024 - 03 Nov. 2024

押さえておきたいアミロイドPET検査の技術的ポイント
我妻慧
第65回多摩核医学技術検討会, 11 Oct. 2024, Japanese, Public discourse
[Invited]

アミロイドPET検査のコツ
我妻慧
GE HealthCare PET Technical Seminar 2024 in 北陸, 29 Jun. 2024, Japanese
29 Jun. 2024 - 29 Jun. 2024

PET核医学エキスパートセミナー 基礎1 PET装置のQA/QC
我妻慧
第24回日本核医学会春季大会, Apr. 2024, Japanese, Public discourse
25 Apr. 2024 - 04 Jun. 2024

PET研修セミナー 臨床PET検査法 PET画像処理
我妻慧
第24回日本核医学会春季大会, Apr. 2024, Japanese, Public discourse
25 Apr. 2024 - 04 Jun. 2024

より良いアミロイドPET撮像のために大切なこと
我妻慧
第83回日本医学放射線学会総会, 11 Apr. 2024, Japanese, Public discourse
11 Apr. 2024 - 14 Apr. 2024

アミロイドPET撮像施設認証の受審経験
我妻慧
第12回 New Clear Imaging Conference, 20 Jan. 2024, Japanese, Invited oral presentation
20 Jan. 2024 - 20 Jan. 2024

StarGuideの画像再構成技術の検討
我妻慧
第1回StarGuide Consprtium, 22 Feb. 2024, Japanese, Others
22 Feb. 2024 - 2024

診療放射線技師の仕事と放射線について
我妻慧
2023年度KGMメディカルセミナー, 21 Nov. 2023, Japanese, Public discourse
21 Nov. 2023 - 21 Nov. 2023, [Invited]

アミロイドPETとタウPETの概要と撮像
我妻慧
第43回日本核医学技術学会総会学術大会, 18 Nov. 2023, Japanese, Invited oral presentation
16 Nov. 2023 - 18 Nov. 2023, [Invited]

JSNMT国際奨励賞受賞講演
我妻慧
第43回日本核医学技術学会総会学術大会, 17 Nov. 2023, Japanese, Invited oral presentation
16 Nov. 2023 - 18 Nov. 2023

PET核医学エキスパートセミナー 基礎1 PET装置のQA/QC
我妻慧
第23回日本核医学会春季大会, Apr. 2023, Japanese, Public discourse
26 Apr. 2023 - 01 Jun. 2023

PET研修セミナー 臨床PET検査法 PET画像処理
我妻慧
第23回日本核医学会春季大会, Apr. 2023, Japanese, Public discourse
26 Apr. 2023 - 01 Jun. 2023

神経変性疾患を捉える脳PET撮像技術
我妻慧
第79回日本放射線技術学会総会学術大会総会学術大会, 15 Apr. 2023, Japanese, Nominated symposium
13 Apr. 2023 - 16 Apr. 2023

アミロイドPETイメージングの撮像技術
我妻慧
神奈川核医学研究会第436回定例研究会, 15 Dec. 2022, Japanese, Invited oral presentation
15 Dec. 2022 - 15 Dec. 2022

アミロイド・タウPET撮像の技術的なトピックス
我妻慧
第19回脳核医学画像解析研究会, 17 Sep. 2022, Japanese, Invited oral presentation

アミロイドPETイメージングの撮像技術
我妻慧
第42回日本核医学技術学会総会学術大会, 09 Sep. 2022, Japanese, Nominated symposium
09 Sep. 2022 - 11 Sep. 2022

論文執筆に挑戦しよう
我妻慧
研究発表トレーニングキャンプ 2022, 04 Sep. 2022, Japanese, Invited oral presentation
02 Sep. 2022 - 04 Sep. 2022

最新PET装置と技術利用
我妻慧
第51回 なにわＲＩセミナー, 20 Jul. 2022, Japanese, Invited oral presentation
20 Jul. 2022 - 20 Jul. 2022

PET核医学エキスパートセミナー 基礎1 PET装置のQA/QC
我妻慧
第22回日本核医学会春季大会, May 2022, Japanese, Public discourse
07 May 2022 - 01 Jun. 2022

PET研修セミナー 臨床PET検査法 PET画像処理
我妻慧
第22回日本核医学会春季大会, May 2022, Japanese, Public discourse
07 May 2022 - 01 Jun. 2022

あらためてPETのQA/QCを考えよう
我妻慧
第50回神奈川PET・SPECT研究会－腫瘍－, 28 May 2022, Japanese, Invited oral presentation
28 May 2022 - 28 May 2022

ファントムの作成方法について
我妻慧
第143回東京支部セミナー, 12 Mar. 2022, Japanese, Public discourse

SiPM-PET/CT、徹底解説!!
我妻慧
第24回New Clear Technologyカンファレンス, 26 Feb. 2022, Japanese, Invited oral presentation

英語論文雑誌の紹介
我妻慧
第265回東京支部技術フォーラム 国際化推進フォーラム『Let's try!! 英語論文』, 22 Jan. 2022, Japanese, Public discourse

徹底解剖、SiPM-PET/CT装置
我妻慧
PETサマーセミナー2021in下呂, 27 Aug. 2021, Japanese, Public discourse
27 Aug. 2021 - 29 Aug. 2021

PET研修セミナー 臨床PET検査法 PET画像処理
我妻慧
第21回 日本核医学会春季大会, Japanese, Public discourse
07 May 2021 - 31 May 2021

ファントムの作成方法について
我妻慧
第134回東京支部セミナー, 13 Mar. 2021, Japanese, Public discourse
13 Mar. 2021 - 13 Mar. 2021

核医学検査機器の保守点検の重要性
我妻慧
第40回日本核医学技術学会総会学術大会, 14 Nov. 2020, Japanese, Keynote oral presentation
12 Nov. 2020 - 14 Nov. 2020

明日からはじめるための認知症PET検査技術
我妻慧
第15回21世紀山口核医学セミナー, 06 Feb. 2020, Japanese, Invited oral presentation
06 Feb. 2020 - 06 Feb. 2020, [Invited]

アミロイド陽電子断層撮像（PET）の臨床使用へ向けた撮像条件の検討
我妻慧; 石橋賢士; 坂田宗之; 多胡哲郎; 豊原潤; 石井賢二
首都大バイオコンファレンス2019, 15 Nov. 2019, Japanese, Public discourse
15 Nov. 2019 - 15 Nov. 2019

SiPM-PET/CT装置『Discovery MI』の臨床的な有用性
我妻慧
第39回日本核医学技術学会総会学術大会, 01 Nov. 2019, Japanese, Nominated symposium
01 Nov. 2019 - 03 Nov. 2019

アミロイド・タウPETにおける撮像技術
我妻慧
PETサマーセミナー2019in福島, 24 Aug. 2019, Japanese, Nominated symposium
23 Aug. 2019 - 25 Aug. 2019

学術研究論文を読むための基礎講座〜研究活動のススメ〜
我妻慧
国立病院関東甲信越放射線技師会「第52回学術研究会」, 25 May 2019, Japanese, Invited oral presentation
25 May 2019 - 25 May 2019, [Invited]

アミロイドPET研究における技術的なトピックス
我妻慧
第914回放射線診療研究会, 04 Feb. 2019, Japanese, Public discourse
04 Feb. 2019 - 04 Feb. 2019, [Invited]

国際化について一緒に考えよう！「スタンフォード大学海外研修で得たモノ，そして現在・・・」
我妻慧
日本放射線技術学会関東・東京支部合同研究発表大会2018, 16 Dec. 2018, Japanese, Public discourse
15 Dec. 2018 - 16 Dec. 2018

PET定量測定の意義と技術的注意点
我妻慧
第13回中国四国医用画像カンファレンス, 30 Jun. 2018, Japanese, Invited oral presentation
30 Jun. 2018 - 30 Jun. 2018, [Invited]

デジタルPETの可能性と有用性
我妻慧
第5回首都圏PETユーザーズミーティング, 16 Jun. 2018, Japanese, Public discourse
16 Jun. 2018 - 16 Jun. 2018

診療放射線技師のこれから
我妻慧
第1回駒澤大学診療放射線研究会, 26 May 2018, Japanese, Nominated symposium
26 May 2018 - 26 May 2018

ここまでわかる脳機能画像，PETを用いた脳機能計測
我妻慧; 石橋賢士; 石井賢二
第35回日本核医学技術学会関東地方会総会, 12 May 2018, Japanese, Nominated symposium
12 May 2018 - 13 May 2018, [Invited]

核医学実験の核心に迫る：PET実験編 3．脳PET領域での研究法
我妻慧
第74回日本放射線技術学会総会学術大会, 14 Apr. 2018, Japanese, Nominated symposium
12 Apr. 2018 - 15 Apr. 2018

半導体（SiPM）PET/CT装置の初期検討と有用性
我妻慧
第27回関東甲信越核医学画像処理研究会, 03 Feb. 2018, Japanese, Invited oral presentation
03 Feb. 2018 - 03 Feb. 2018, [Invited]

SiPM-PET/CTの性能評価と初期検討
我妻慧
第906回放射線診療研究会, 06 Nov. 2017, Japanese, Public discourse
06 Nov. 2017 - 06 Nov. 2017, [Invited]

アミロイドPETに求められるもの
我妻慧
PETサマーセミナー2017in奈良, 26 Aug. 2017, Japanese, Public discourse
25 Aug. 2017 - 27 Aug. 2017

Discover MIの使用経験〜脳領域における技師の立場から〜
我妻慧
PETサマーセミナー2017in奈良, 25 Aug. 2017, Japanese, Public discourse
25 Aug. 2017 - 27 Aug. 2017

SiPM-PET/CT Discovery MIの性能評価と基礎検討
我妻慧
PETサマーセミナー2017in奈良, 25 Aug. 2017, Japanese, Invited oral presentation
25 Aug. 2017 - 27 Aug. 2017, [Invited]

核医学技術におけるPETの最前線
我妻慧
第220回東京支部技術フォーラム, 07 Jul. 2017, Japanese, Public discourse
07 Jul. 2017 - 07 Jul. 2017

表示付認証機器を用いたSPECTのQC・QA
我妻慧
第13回Molecular Imaging Technologist Conference, 09 Dec. 2016, Japanese, Invited oral presentation
09 Dec. 2016 - 09 Dec. 2016, [Invited]

技術的側面におけるアミロイドPETイメージングの基礎のキソ
我妻慧
第56回日本核医学会学術総会, 04 Nov. 2016, Japanese, Invited oral presentation
03 Nov. 2016 - 05 Nov. 2016, [Invited]

臨床応用を目指したPET薬剤の次世代化，シンポジウム[薬剤]次世代の核医学イメージング剤
豊原潤; 多胡哲郎; 坂田宗之; 石橋賢士; 我妻慧; 石渡喜一; 石井賢二
第56回日本核医学会学術総会, 04 Nov. 2016, Japanese, Nominated symposium
03 Nov. 2016 - 05 Nov. 2016

認知症被検者の医療安全〜診療放射線技師の立場から〜
我妻慧
第56回日本核医学会学術総会, 03 Nov. 2016, Japanese, Nominated symposium
03 Nov. 2016 - 05 Nov. 2016

ファントムを用いた脳PETイメージングの技術的検討
我妻慧
第14回脳核医学画像解析研究会, 10 Sep. 2016, Japanese, Invited oral presentation
10 Sep. 2016 - 10 Sep. 2016, [Invited]

PETにおける定量
我妻慧
第32回インフォーマルミーティング, 09 Jan. 2016, Japanese, Public discourse
09 Jan. 2016 - 09 Jan. 2016

AI超解像処理を用いたタウPET画像の高精度化とアルツハイマー病病態評価
科学研究費助成事業
Apr. 2026 - Mar. 2029
我妻 慧
日本学術振興会, 基盤研究(C), 北海道大学, Principal investigator, 26K10553

タウPET標準化を目指した新しいファントムの開発と全国展開
科学研究費助成事業 若手研究
Apr. 2023 - Mar. 2026
我妻 慧
日本学術振興会, 若手研究, 北里大学, Principal investigator, 23K14875

深層学習を用いた超解像度技術のタウPET 画像への応用
北里大学医療衛生学部 2024年度特別研究費
Jun. 2024 - Mar. 2025
三輪建太; 山尾天翔
北里大学医療衛生学部, 北里大学医療衛生学部, Principal investigator

タウPET 専用ファントムの解析手法の確立
「放射線災害・医科学研究拠点」共同利用・共同研究
Apr. 2024 - Mar. 2025
三輪建太
放射線災害・医科学研究拠点, 2024年度「放射線災害・医科学研究拠点」共同利用・共同研究, 北里大学医療衛生学部, Principal investigator

機械学習を用いた高解像度技術のタウPET 画像への応用
北里大学医療衛生学部 2023年度特別研究費
Jun. 2023 - Mar. 2024
我妻慧、小川恵美悠、三輪建太
北里大学医療衛生学部, 北里大学, Principal investigator

タウPET 専用ファントムの解析手法の確立
「放射線災害・医科学研究拠点」共同利用・共同研究
Apr. 2023 - Mar. 2024
三輪建太
放射線災害・医科学研究拠点, 2023年度「放射線災害・医科学研究拠点」共同利用・共同研究, 北里大学医療衛生学部, Principal investigator

Development of standardization method of tau-PET imaging in Alzheimer's disease
Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists
01 Apr. 2020 - 31 Mar. 2023
我妻 慧
2021年度、タウPET専用のファントムとして、分解能、画像ノイズ、画像コントラストを一度の撮像で評価が可能なタウPET専用のファントムを作成した。既存の評価ファントムでは画像コントラストと画像ノイズを一度に評価をすることができなかったが、本申請で作成したファントムでこれらの評価指標を一度に評価が可能となった。2020年度に明らかにしたタウPETを模擬する放射能条件は既存のファントムを考慮して決定したため、本年度に作成したタウPET専用のファントムに対応して放射能条件を微調整してタウPET専用のファントムの放射能条件を明らかにした。タウPET専用のファントムの均一部分を使用して画像ノイズを測定することができ、タウPET専用のファントムの画像ノイズは既存のファントムの評価結果と遜色のない結果であった。画像コントラストおよび分解能はタウPET専用のファントムの脳を模擬した部分を使用する。また、本研究では2021年に欧州の多施設研究の脳PET撮像の標準化で使用されている脳PETの定量性を示す指標であるリカバリ係数を採用することとした。タウPET専用のファントムの画像の画像コントラストと定量性は既存のファントムの結果と比較して過小評価されていることがわかった。この結果から、タウPET専用のファントムで解析に使用している手法が既存のファントムをベースに作成しているため、ファントム自体の違いによる影響が出ていると考えた。2022年度はこの解析方法の最適化を目指す。タウPET専用ファントムの脳を模擬した部分の画像は脳の構造をよく再現していることがわかった。アルツハイマー病ではタウ蛋白病変が側頭葉内側から沈着する。タウPET専用ファントムの脳を模擬した部分は側頭葉に相当する。本研究によってアルツハイマー病に伴うタウ蛋白の沈着を的確にとらえ、早期発見および重症度評価の可能性が示された。
Japan Society for the Promotion of Science, Grant-in-Aid for Early-Career Scientists, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, 20K16747

アルツハイマー病診断のための標準的タウPETイメージングの解析法の開発
2022年度特別研究費
Jun. 2022 - Mar. 2023
北里大学医療衛生学部, 2022年度特別研究費, 北里大学医療衛生学部, Principal investigator

タウPET 専用ファントムの解析手法の確立
「放射線災害・医科学研究拠点」共同利用・共同研究
Apr. 2022 - Mar. 2023
三輪建太
放射線災害・医科学研究拠点, 2022年度「放射線災害・医科学研究拠点」共同利用・共同研究, 北里大学医療衛生学部, Principal investigator

あらゆるタウPET薬剤に対応した標準的撮像法と新しい客観的評価法の開発
令和2年度理事長奨励研究
Jun. 2020 - Mar. 2021
坂田宗之
東京都健康長寿医療センター, 令和2年度理事長奨励研究費, 東京都健康長寿医療センター, Principal investigator

Molecular imaging of adenosine A2A receptor: a first-in-human study
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
01 Apr. 2016 - 31 Mar. 2019
ISHIWATA KIICHI; KUBO hitoshi; MIZUNO yasuaki; ISHII kenji; WAGATSUMA Kei
We performed first clinical PET studies using 11C-preladenant (PLN) for imaging adenosine A2A receptor in the human brain. PLN-PET provided acceptable dosimetry and pharmacological safety. The PLN binding in brain regions was well correspond to the adenosine A2A receptor distribution in the brain.
In drug-naive patients with Parkinson’s disease, the PLN binding did not changed in the striatum with age-matched healthy subjects, but bilateral difference in the head of caudate nucleus was slightly larger in the patients. In patients given the therapeutic doses of istradefylline occupancy rates of adenosine A2A receptors were about 70% at most in the striatum. These findings demonstrated that PLN-PET becomes a new tool for pathphysiological studies of neurodegenerative disease.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Southen Tohoku Research Institute for Neuroscience, 16H05396

Automatic differential dementia diagnosis using brain FDG-PET, MRI, and machine learning
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
01 Apr. 2015 - 31 Mar. 2018
Sakata Muneyuki; ISHII Kenji; WAGATSUMA Kei; KIMURA Yuichi
Differential diagnosis of dementia type is necessary for treatment and care of dementia. In this research, we provided an automatic discrimination using machine learning of brain FDG-PET images and MR images. Support vector machines were employed for training of extracted features from FDG-PET images as the index of hypometabolism, and MR images as the index of cerebral atrophy. To support the clinical diagnosis, the system automatically classifies the groups of Alzheimer’s disease, front-temporal dementia, dementia with Lewy bodies, and healthy subjects, and indicates a novel image index for severity or progression of the dementia from the classification.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, 15K09982

Molecular imaging of metablotropic glutamate receptor type 1 – a first-in-human study
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
01 Apr. 2012 - 31 Mar. 2016
ISHIWATA Kiichi; MISHINA Masahiro; SAKATA Muneyuki; ISHIBASHI Kenji; ISHII Kenji; TOYOHARA Jun; ODA Keiichi; WAGATSUMA Kei; CHOU Meiei
We performed first clinical PET studies using [11C]ITMM for imaging metablotropic glutamate receptor type 1 (mGluR1) in the human brain. [11C]ITMM-PET provided acceptable dosimetry and pharmacological safety. The [11C]ITMM binding in brain regions was well correspond to the mGluR1 distribution in the brain, suggesting that [11C]ITMM-PET becomes a new tool for pathphysiological studies of neurodegenerative disease.
In healthy subjects [11C]ITMM binding increased in several brain regions of the elderly subjects. In patients with hereditary and sporadic cerebellar ataxia, the [11C]ITMM binding significantly decreased in cerebellar region compared with age-matched healthy subjects. The measurement of mGluR1 availability would be more sensitive than morphological measure by MRI. In Parkinson’s disease the binding decreased in cerebellum and temporal and parietal lobes. Preliminarily mGluR1 availability were regionally changed in the brain of patients with Alzheimer’s disease and epilepsy.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, 24390298

Physica Medica: European Journal of Medical Physics
2021 - Present
Peer review
Peer review etc
European Journal of Medical Physics

Annals of Nuclear Medicine
2018 - Present
Peer review
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Japanese Society of Neuclear Medicine

日本放射線技術学会雑誌
2016 - Present
Peer review
Peer review etc
日本放射線技術学会

Radiological Physics and Technology
2015 - Present
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Peer review etc

Asia Oceania Journal of Nuclear Medicine and Biology
2017 - 2021
Peer review
Peer review etc

核医学技術
2019 - 2020
Peer review
Peer review etc
日本核医学技術学会