2026/09/02 更新

所属以外の情報はresearchmapへの登録情報を転載しています。

写真a

イシワタ ヨシノブ
石渡 義之
Yoshinobu Ishiwata
所属
附属病院 核医学診療科 講師
職名
講師
プロフィール

視線計測を用いた効率的な画像読影の研究および核医学の研究を行なっています。

外部リンク

学位

  • 博士(医学) ( 横浜市立大学 )

研究キーワード

  • 人工知能

  • PET

  • 18F-NaF

  • 放射線医学

  • 核医学

  • 認知行動科学

  • 視線計測

研究分野

  • ライフサイエンス / 放射線科学

所属学協会

論文

  • Clinical Robustness of FDG-PET/CT Quantitative Metrics Post-Harmonization in a Multicenter, Cross-Scanner Setting

    Ayako Hino, Yoshinobu Ishiwata, Akira Kakiuchi, Tomohiro Numata, Hiroyuki Kamide, Hiroaki Kurihara, Zenjiro Sekikawa, Daisuke Utsunomiya

    Tomography   12 ( 7 )   104 - 104   2026年7月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:MDPI AG  

    Background/Objectives: Differences among scanners and reconstruction methods may limit the comparability of quantitative metrics derived from fluorodeoxyglucose positron emission tomography (FDG PET)/computed tomography (CT). Although harmonization reduces inter-scanner variability in standardized uptake values (SUVs), its impact on the preservation of lesion-level ranking in real-world clinical datasets remains unclear. Here, we evaluated the robustness of PET quantitative metrics, particularly focusing on rank preservation after harmonization. Methods: Phantom and clinical data retrospectively acquired from three institutions using four PET/CT scanner types were analyzed. Harmonization parameters were derived from National Electrical Manufacturers Association IEC Body Phantom data, using the oldest scanner as the reference, and were directly applied to the clinical datasets. Clinical evaluation included head and neck malignant melanoma (HNMM; high FDG avidity) and adenoid cystic carcinoma (ACC; low FDG avidity). Rank preservation between pre- and post-harmonization values was assessed using Spearman’s rank correlation coefficient (ρ). Results: Phantom-based harmonization reduced inter-scanner differences and enabled consistent evaluation in clinical datasets (HNMM: 34 patients, 93 lesions; ACC: 18 patients, 38 lesions). SUVpeak demonstrated the highest rank preservation across tumor types and lesion sizes (ρ = 0.94–1.00). Metabolic tumor volume (MTV) showed a high rank correlation in HNMM with an absolute threshold (MTV2.5; ρ = 0.99), but robustness varied depending on threshold definition, tumor type, and lesion size. Tumor-to-liver ratios showed moderate rank preservation. Conclusions: Our results suggested that SUVpeak is the most robust preservation of lesion ranking across tumor types after harmonization, suggesting its suitability as a reliable imaging biomarker in multicenter studies. Meanwhile, careful standardization is needed when using MTV-based metrics for prognostic evaluation.

    DOI: 10.3390/tomography12070104

    researchmap

  • Risk-Stratified Use of Concurrent Computer-Aided Diagnosis (CAD) in Chest CT: Gains in Overall Sensitivity with Loss for CAD-Negative Nodules. 国際誌

    Yoshinobu Ishiwata, Ryo Aoki, Keiichi Horie, Shinjiro Aso, Masaaki Futaki, Yuka Takeuchi, Yuka Misumi, Sayuri Inagaki, Akira Haga, Ayumi Kato, Shoichiro Matsushita, Shingo Kato, Tsuneo Yamashiro, Daisuke Utsunomiya

    Journal of imaging informatics in medicine   2026年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    This study quantifies how concurrent computer-aided detection/diagnosis (CAD) alters radiologists' performance in chest CT, emphasizing CAD-negative nodules and the trade-off between overall sensitivity and detection of unmarked lesions. We enrolled 150 consecutive patients undergoing thin-section chest CT. A reference standard of 334 nodules (93% < 10 mm) was established by consensus. Six readers (3 novice, 3 expert) interpreted each scan without CAD and, after a 4-week washout, reinterpreted them with CAD overlays visible from the outset (concurrent reading, outside the recommended workflow). We analyzed sensitivity, case-based specificity, and reading time. Overall sensitivity improved from 47 to 59% (p < 0.01) and mean reading time decreased by 42.8 s (p < 0.01). Conversely, sensitivity for the 75 CAD-negative nodules declined significantly (novices, - 20 percentage points; experts, - 16 points; both p < 0.01). Mixed-effects logistic regression confirmed lower odds of detecting CAD-negative nodules with concurrent CAD (OR, 0.34; 95% CI, 0.25-0.47). Gains were driven by 3-9 mm nodules, while < 3 mm lesions showed no benefit. Reader case-based specificity rose from 75 to 82% with CAD assistance. Concurrent CAD improved overall sensitivity and interpretation speed but significantly reduced sensitivity for CAD-negative nodules, consistent with reduced search vigilance for unprompted regions. Because most CAD-negative nodules were ≤ 6 mm, risk-stratified CAD workflows should be validated prospectively before broad clinical adoption.

    DOI: 10.1007/s10278-026-02036-5

    PubMed

    researchmap

  • Plaque regression and stabilization by proprotein convertase subtilisin/kexin type 9 inhibitors: a meta-analysis of intravascular imaging studies. 国際誌

    Ryu Umezono, Shingo Kato, Naofumi Yasuda, Shungo Sawamura, Yoshinobu Ishiwata, Nobuyuki Horita, Daisuke Utsunomiya

    Coronary artery disease   2026年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND AND AIMS: Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are potent lipid-lowering agents that may also influence the structural and compositional features of coronary atherosclerotic plaques. Although individual intravascular imaging modalities have demonstrated beneficial effects, an integrated evaluation across modalities remains limited. METHODS: We performed a systematic review and meta-analysis of studies evaluating the impact of PCSK9 inhibitors on coronary plaque using intravascular ultrasound, near-infrared spectroscopy, and optical coherence tomography. PubMed, Web of Science, and the Cochrane Library were searched up to June 2025. The primary outcomes were changes in percent atheroma volume (PAV), fibrous cap thickness (FCT), and maximum lipid core burden index within 4 mm (maxLCBI4 mm). A random-effects model was used to pool results. RESULTS: Ten studies with a total of 1642 patients (PCSK9 inhibitor group: 816; control group: 826) were included. PCSK9 inhibitors significantly reduced PAV compared with control [mean difference: -1.03%; 95% confidence interval (CI): -1.46 to -0.60; P < 0.00001; I2 = 27%]. Minimum FCT showed an increase (mean difference: 28.44 μm; 95% CI: 6.10-50.77; P = 0.01; I2 = 82%). Furthermore, PCSK9 inhibitors reduced maxLCBI4 mm (mean difference: -39.73; 95% CI: -65.49 to -13.98; P = 0.002). CONCLUSION: This comprehensive intravascular imaging meta-analysis demonstrates that PCSK9 inhibitors are associated with both regression and stabilization of coronary plaques, as evidenced by reductions in PAV and lipid content and increases in fibrous cap thickness. These imaging-based structural changes may underlie the cardiovascular benefits observed in major outcome trials.

    DOI: 10.1097/MCA.0000000000001639

    PubMed

    researchmap

  • Impact of Resuscitative Endovascular Balloon Occlusion of the Aorta on In-Hospital and Short-Term Mortality: A Systematic Review and Meta-Analysis. 国際誌

    Hiroyuki Kamide, Shingo Kato, Naofumi Yasuda, Shungo Sawamura, Yoshinobu Ishiwata, Nobuyuki Horita, Ryusuke Sekii, Tomohiro Oshima, Zenjiro Sekikawa, Daisuke Utsunomiya

    Diseases (Basel, Switzerland)   14 ( 4 )   2026年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is increasingly employed in patients with hemorrhagic shock and cardiovascular collapse; however, its impact on mortality remains controversial. Differences in geographic regions and patient populations may influence clinical outcomes. METHODS: We conducted a systematic review and meta-analysis of observational studies comparing mortality between patients receiving REBOA and those managed without REBOA. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using random-effects models. Subgroup analyses were performed according to propensity score (PS) matching, trauma versus non-trauma populations, and geographic regions. RESULTS: A total of 10 studies involving 18,611 patients were included. Overall, REBOA was not associated with a significant reduction in mortality compared with non-REBOA (pooled OR = 0.52, 95% CI: 0.19-1.39, p = 0.19). In PS-matched studies, the pooled OR was 0.82 (95% CI: 0.34-1.98, p = 0.66), whereas in non-PS-matched studies it was 0.40 (95% CI: 0.12-1.26, p = 0.12). Geographic analyses revealed no significant mortality benefit in either Western studies (OR = 0.47, 95% CI: 0.12-1.89; p = 0.29) or non-Western studies (OR = 0.60, 95% CI: 0.11-3.38; p = 0.56). No survival benefit was observed among trauma patients (OR = 0.57, 95% CI: 0.20-1.61; p = 0.29), whereas a significant reduction in mortality was observed in non-trauma patients (OR = 0.21, 95% CI: 0.05-0.88; p = 0.03). CONCLUSIONS: In this systematic review and meta-analysis, REBOA was not associated with a significant reduction in mortality in the overall population or in trauma patients. However, in a single small non-trauma study (n = 53), REBOA was associated with significantly reduced mortality; this finding is exploratory and requires confirmation in larger prospective studies. These findings suggest that the clinical benefit of REBOA may depend on patient population and underlying etiology of hemorrhage.

    DOI: 10.3390/diseases14040122

    PubMed

    researchmap

  • Accelerating imaging: deep learning for enhanced 123I-ioflupane SPECT efficiency.

    Yoshinobu Ishiwata, Keiichi Horie, Kazuhiro Aritome, Ryo Aoki, Hitoshi Iizuka, Shinjiro Aso, Yuka Takeuchi, Yuka Misumi, Akira Haga, Shingo Kato, Tsuneo Yamashiro, Shoko Takano, Daisuke Utsunomiya

    Japanese journal of radiology   2025年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: Conventional 123I-ioflupane dopamine-transporter SPECT requires 25-40 min of acquisition, causing patient discomfort and limiting throughput. This study assessed whether deep-learning (DL) reconstruction can yield diagnostic-quality images from a 5-min scan. METHODS: We retrospectively analysed 207 studies (1035 slices) obtained between April 2018 and June 2020. After cropping to 64 × 64 striatal regions, 600, 185 and 250 images from 120, 37 and 50 patients were used for training, validation and testing. Six convolutional architectures-U-Net (one-five depths), V-Net, U-Net +  + , R2U-Net, Attention U-Net and TransUNet-were trained to translate 5-min into virtual 25-min images. Image quality was assessed with peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM), analysed by Friedman and Dunn-Holm tests. A blinded reader study involved three nuclear medicine physicians grading 50 cases (100 striata) on a four-point scale; agreement with the 25-min consensus was measured by weighted κ and intra-/inter-observer intraclass correlation coefficients (ICC). RESULTS: All DL reconstructions significantly outperformed raw 5-min images in PSNR and SSIM (p < 0.01). The four-layer U-Net achieved the highest quality (PSNR 32.7 ± 1.7 dB, SSIM 0.842 ± 0.069), ≈1.8 dB and 0.13 higher than baseline, and statistically indistinguishable from 25-min images (p > 0.05). Reader concordance improved from fair with baseline (κ = 0.29-0.41) to substantial with the four-layer U-Net (κ = 0.62-0.70); intra-reader ICC was 0.84-0.93 and inter-reader ICC 0.73-0.75. CONCLUSIONS: A compact four-layer U-Net restores diagnostic fidelity to 5-min 123I-ioflupane SPECT, enabling an 80% reduction in scan time without loss of quantitative metrics or interpretability. DL-accelerated protocols may enhance comfort, reduce motion artefacts and increase throughput, warranting prospective multicentre validation.

    DOI: 10.1007/s11604-025-01933-z

    PubMed

    researchmap

  • Digital FDG-PET detects MYD88 mutation-driven glycolysis in primary central nervous system lymphoma. 国際誌

    Mayu Sasaki, Yuri Teraoka, Ayumi Kato, Tadaaki Nakajima, Yoshinobu Ishiwata, Yohei Miyake, Hirokuni Honma, Taishi Nakamura, Naoki Ikegaya, Yutaro Takayama, Osamu Yazawa, Shungo Sawamura, Akito Oshima, Hiroaki Hayashi, Wei Kai Ye, Kanoko Sasaoka, Yukie Yoshii, Satoshi Fujii, Ukihide Tateishi, Tetsuya Yamamoto, Daisuke Utsunomiya, Shingo Kato, Kensuke Tateishi

    AJNR. American journal of neuroradiology   2025年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND AND PURPOSE: The relationship between digital 18F-fluorodeoxyglucose positron emission tomography (dFDG-PET) findings and glucose metabolism-related genetic alterations remains unclear in primary central nervous system lymphoma (PCNSL). This study aimed to evaluate whether dFDG-PET can serve as a noninvasive tool to detect MYD88 mutation-driven glycolytic activity in PCNSL. MATERIALS AND METHODS: We retrospectively analyzed the imaging and molecular data of 54 patients with PCNSL (55 lesions). MRI and FDG-PET parameters, including the maximum standardized uptake value (SUVmax) and tumor-to-background ratio (TBR), were assessed. Tumor specimens were subjected to histopathological and genomic evaluations, including the MYD88 mutation status. RESULTS: Among 55 tumors, 34 (61.8%) were examined with dFDG-PET and 21 (38.2%) with analog 18F-FDG-PET (aFDG-PET). In the dFDG-PET group, MYD88-mutant tumors showed significantly higher SUVmax (30.2 ± 9.9) and TBR (6.1 ± 1.5) compared to wild-type tumors (SUVmax: 19.3 ± 7.2, P = 0.006; TBR: 3.5 ± 1.3, P < 0.001). In the aFDG-PET group, the SUVmax was significantly higher in MYD88-mutant tumors (P = 0.01), whereas the TBR differences were not statistically significant (P = 0.38). Receiver operating characteristic analysis of TBR in dFDG-PET yielded an area under the curve of 0.913 (95% CI: 0.954-1.000) with a cutoff value of 4.49, achieving 88% sensitivity and 88% specificity for MYD88 mutation detection. Multivariate logistic regression identified SUVmax and TBR from dFDG-PET as independent predictors of MYD88 mutation status. The transcriptomic analysis confirmed the significant upregulation of glycolysis-related genes, including hexokinase 2, in MYD88-mutant tumors, supporting increased glycolytic activity. CONCLUSIONS: dFDG-PET may serve as a valuable noninvasive imaging modality to detect MYD88 mutation-driven enhanced glycolysis in patients with PCNSL. ABBREVIATIONS: dPET= Digital positron emission tomography; PCNSL= Primary central nervous system lymphoma; SUVmax=maximum standardized uptake value; TBR= tumor-to background ratio.

    DOI: 10.3174/ajnr.A8935

    PubMed

    researchmap

  • Correction: Cardiac overload resolved by resection of a large plexiform neurofibroma on both the buttocks and upper posterior thighs in a patient with neurofibromatosis type I: a case report. 国際誌

    Taro Mikami, Yuki Honma-Koretsune, Yui Tsunoda, Shintaro Kagimoto, Yuichiro Yabuki, Jiro Maegawa, Miki Terauchi, Shintaro Nawata, Hiroyuki Kamide, Yoshinobu Ishiwata, Tabito Kino, Teruyasu Sugano

    BMC surgery   24 ( 1 )   335 - 335   2024年10月

     詳細を見る

  • Evaluation of PET/CT imaging with [89Zr]Zr-DFO-girentuximab: a phase 1 clinical study in Japanese patients with renal cell carcinoma (Zirdac-JP) 査読

    Noboru Nakaigawa, Hisashi Hasumi, Daisuke Utsunomiya, Keisuke Yoshida, Yoshinobu Ishiwata, Takashi Oka, Colin Hayward, Kazuhide Makiyama

    Japanese Journal of Clinical Oncology   54 ( 8 )   873 - 879   2024年6月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Oxford University Press (OUP)  

    Abstract

    Background

    PET/CT imaging with Zirconium-89 labeled [89Zr]Zr-DFO-girentuximab, which targets tumor antigen CAIX, may aid in the differentiation and characterization of clear cell renal cell carcinomas (RCC) and other renal and extrarenal lesions, and has been studied in European and American cohorts. We report results from a phase I study that evaluated the safety profile, biodistribution, and dosimetry of [89Zr]Zr-DFO-girentuximab in Japanese patients with suspected RCC.

    Methods

    Eligible adult patients received 37 MBq (± 10%; 10 mg mass dose) of intravenous [89Zr]Zr-DFO-girentuximab. Safety and tolerability profile was assessed based on adverse events, concomitant medications, physical examination, vital signs, hematology, serum chemistry, urinalysis, human anti-chimeric antibody measurement, and 12-lead electrocardiograms at predefined intervals. Biodistribution and normal organ and tumor dosimetry were evaluated with PET/CT images acquired at 0.5, 4, 24, 72 h and Day 5 ± 2 d after administration.

    Results

    [89Zr]Zr-DFO-girentuximab was administered in six patients as per protocol. No treatment-emergent adverse events were reported. Dosimetry analysis showed that radioactivity was widely distributed in the body, and that the absorbed dose in healthy organs was highest in the liver (mean ± standard deviation) (1.365 ± 0.245 mGy/MBq), kidney (1.126 ± 0.190 mGy/MBq), heart wall (1.096 ± 0.232 mGy/MBq), and spleen (1.072 ± 0.466 mGy/MBq). The mean effective dose, adjusted by the radioactive dose administered, was 0.470 mSv/MBq. The radiation dose was highly accumulated in the targeted tumor, while any abnormal accumulation in other organs was not reported.

    Conclusions

    This study demonstrates that [89Zr]Zr-DFO-girentuximab administered to Japanese patients with suspected RCC has a favorable safety profile and is well tolerated and has a similar dosimetry profile to previously studied populations.

    DOI: 10.1093/jjco/hyae075

    researchmap

  • Comparative Analysis of Eye Tracking between Veteran and Novice during Radiological Interpretation 査読

    Yuka Naito, Jun Nakamura, Yoshinobu Ishiwata

    Proceedings of the 2024 International Conference on Artificail Life and Robotics(ICAROB2024).   2024年2月

     詳細を見る

  • Visualization of the Skilled Physician’s Gaze Characteristic during Diagnosis 査読

    Taiki Sugimoto, Jun Nakamura, Yoshinobu Ishiwata

    Proceedings of the 2024 International Conference on Artificail Life and Robotics(ICAROB2024).   2024年2月

     詳細を見る

  • Stomach position evaluated using computed tomography is related to successful post-pyloric enteral feeding tube placement in critically ill patients: a retrospective observational study. 査読 国際誌

    Masashi Yokose, Shunsuke Takaki, Yusuke Saigusa, Takahiro Mihara, Yoshinobu Ishiwata, Shingo Kato, Keiichi Horie, Takahisa Goto

    Journal of intensive care   11 ( 1 )   25 - 25   2023年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: Post-pyloric enteral feeding reduces respiratory complications and shortens the duration of mechanical ventilation. Blind placement of post-pyloric enteral feeding tubes (EFT) in patients with critical illnesses is often the first-line method because endoscopy or fluoroscopy cannot be easily performed at bedside; however, difficult placements regularly occur. We reported an association between the stomach position caudal to spinal level L1-L2, evaluated by abdominal radiographs after placement, and difficult placement; however, this method could not indicate difficulty before EFT placement. The aim of our study was to evaluate the association between stomach position, estimated using computed tomography (CT) images taken before the blind placement of the post-pyloric EFT, and the difficulty of EFT placement. METHODS: Data from patients aged ≥ 20 years who underwent post-pyloric EFT in our intensive care unit were obtained retrospectively. Logistic regression analysis was used to evaluate the association between successful initial EFT placement and explanatory variables, including stomach position estimated by CT. Two cut-off values were used: caudal to L1-L2 based on a previous study and the best cut-off value calculated by the receiver operating characteristic curve. Variable selection was performed backward stepwise using Akaike's Information Criterion. RESULTS: Of the total of 453 patients who were enrolled, the success rate of the initial EFT placement was 43.5%. The adjusted odds ratio for successful initial EFT placement of the stomach position caudal to L1-L2 was 0.61 (95% confidence interval: 0.41-1.07). Logistic regression analysis, including the stomach position caudal to L2-L3, calculated as the best cut-off value, indicated that stomach position was an independent factor for failure of initial EFT placement (adjusted odds ratio, 0.55; 95% confidence interval: 0.33-0.91). CONCLUSIONS: Stomach position evaluated using CT images was associated with successful initial post-pyloric EFT placement. The best cut-off value of the greater curvature of the stomach to predict the success or failure of the first attempt was spinal level L2-L3. Trial registration University Hospital Medical Information Network Clinical Trials Registry (UMIN000046986; February 28, 2022). https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000052151.

    DOI: 10.1186/s40560-023-00673-4

    PubMed

    researchmap

  • Assessing Therapeutic Response to Radium-223 with an Automated Bone Scan Index among Metastatic Castration-Resistant Prostate Cancer Patients: Data from Patients in the J-RAP-BSI Trial 査読

    Kazuhiro Kitajima, Junpei Kuyama, Takashi Kawahara, Tsuyoshi Suga, Tomoaki Otani, Shigeyasu Sugawara, Yumiko Kono, Yukihisa Tamaki, Ayumi Seko-Nitta, Yoshinobu Ishiwata, Kimiteru Ito, Akira Toriihara, Shiro Watanabe, Makoto Hosono, Hideaki Miyake, Shingo Yamamoto, Ryohei Sasaki, Mitsuhiro Narita, Koichiro Yamakado

    Cancers   15 ( 10 )   2784 - 2784   2023年5月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:MDPI AG  

    To evaluate the usefulness of change in the automated bone scan index (aBSI) value derived from bone scintigraphy findings as an imaging biomarker for the assessment of treatment response and survival prediction in metastatic castration-resistant prostate cancer (mCRPC) patients treated with Ra-223. This study was a retrospective investigation of a Japanese cohort of 205 mCRPC patients who received Ra-223 in 14 hospitals between July 2016 and August 2020 and for whom bone scintigraphy before and after radium-223 treatment was available. Correlations of aBSI change, with changes in the serum markers alkaline phosphatase (ALP) and prostate-specific antigen (PSA) were evaluated. Additionally, the association of those changes with overall survival (OS) was assessed using the Cox proportional-hazards model and Kaplan–Meier curve results. Of the 205 patients enrolled, 165 (80.5%) completed six cycles of Ra-223. Following treatment, ALP decline (%ALP &lt; 0%) was noted in 72.2% (148/205), aBSI decline (%aBSI &lt; 0%) in 52.7% (108/205), and PSA decline (%PSA &lt; 0%) in 27.8% (57/205). Furthermore, a reduction in both aBSI and ALP was seen in 87 (42.4%), a reduction in only ALP was seen in 61 (29.8%), a reduction in only aBSI was seen in 21 (10.2%), and in both aBSI and ALP increasing/stable (≥0%) was seen in 36 (17.6%) patients. Multiparametric analysis showed changes in PSA [hazard ratio (HR) 4.30, 95% confidence interval (CI) 2.32–8.77, p &lt; 0.0001], aBSI (HR 2.22, 95%CI 1.43–3.59, p = 0.0003), and ALP (HR 2.06, 95%CI 1.35–3.14, p = 0.0008) as significant prognostic factors for OS. For mCRPC patients treated with Ra-223, aBSI change is useful as an imaging biomarker for treatment response assessment and survival prediction.

    DOI: 10.3390/cancers15102784

    researchmap

  • Novel nomogram developed for determining suitability of metastatic castration-resistant prostate cancer patients to receive maximum benefit from radium-223 dichloride treatment-Japanese Ra-223 Therapy in Prostate Cancer using Bone Scan Index (J-RAP-BSI) Trial. 査読 国際誌

    Kazuhiro Kitajima, Masataka Igeta, Junpei Kuyama, Takashi Kawahara, Tsuyoshi Suga, Tomoaki Otani, Shigeyasu Sugawara, Yumiko Kono, Yukihisa Tamaki, Ayumi Seko-Nitta, Yoshinobu Ishiwata, Kimiteru Ito, Akira Toriihara, Shiro Watanabe, Makoto Hosono, Hideaki Miyake, Shingo Yamamoto, Mitsuhiro Narita, Takashi Daimon, Koichiro Yamakado

    European journal of nuclear medicine and molecular imaging   2022年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    PURPOSE: To develop a novel nomogram for determining radium-223 dichloride (Ra-223) treatment suitability for metastatic castration-resistant prostate cancer (mCRPC) patients. METHODS: This Japanese Ra-223 Therapy in Prostate Cancer using Bone Scan Index (J-RAP-BSI) Trial was a retrospective multicenter investigation enrolled 258 mCRPC patients in Japan with Ra-223 treatment between June 2016 and August 2020, with bone scintigraphy findings before treatment, clinical data, and survival outcome available. A nomogram was constructed using prognostic factors for overall survival (OS) based on a least absolute shrinkage and selection operator Cox regression model. A sub-analysis was also conducted for patients meeting European Medicines Agency (EMA) guidelines. RESULTS: Within a median of 17.4 months after initial Ra-223 treatment, 124 patients (48.1%) died from prostate cancer. Predictive factors included (1) sum of prior treatment history (score 0, never prior novel androgen receptor-targeted agents (ARTA) therapy, never prior taxane-based chemotherapy, and ever prior bisphosphonate/denosumab treatment), (2) Eastern Cooperative Oncology Group (ECOG) performance status, (3) prostate-specific antigen doubling time (PSADT), (4) hemoglobin, (5) lactate dehydrogenase (LDH), and (6) alkaline phosphatase (ALP) levels, and (7) automated bone scan index (aBSI) value based on bone scintigraphy. The nomogram using those factors showed good discrimination, with apparent and optimism-corrected Harrell's concordance index values of 0.748 and 0.734, respectively. Time-dependent area under the curve values at 1, 2, and 3 years were 0.771, 0.818, and 0.771, respectively. In 227 patients meeting EMA recommendation, the nomogram with seven factors showed good discrimination, with apparent and optimism-corrected Harrell's concordance index values of 0.722 and 0.704, respectively. Time-dependent area under the curve values at 1, 2, and 3 years were 0.747, 0.790, and 0.759, respectively. CONCLUSION: This novel nomogram including aBSI to select mCRPC patients to receive Ra-223 with significantly prolonged OS possibility was found suitable for assisting therapeutic decision-making, regardless of EMA recommendation.

    DOI: 10.1007/s00259-022-06082-3

    PubMed

    researchmap

  • Comparison of CO-RADS Scores Based on Visual and Artificial Intelligence Assessments in a Non-Endemic Area. 査読 国際誌

    Yoshinobu Ishiwata, Kentaro Miura, Mayuko Kishimoto, Koichiro Nomura, Shungo Sawamura, Shigeru Magami, Mizuki Ikawa, Tsuneo Yamashiro, Daisuke Utsunomiya

    Diagnostics (Basel, Switzerland)   12 ( 3 )   2022年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In this study, we first developed an artificial intelligence (AI)-based algorithm for classifying chest computed tomography (CT) images using the coronavirus disease 2019 Reporting and Data System (CO-RADS). Subsequently, we evaluated its accuracy by comparing the calculated scores with those assigned by radiologists with varying levels of experience. This study included patients with suspected SARS-CoV-2 infection who underwent chest CT imaging between February and October 2020 in Japan, a non-endemic area. For each chest CT, the CO-RADS scores, determined by consensus among three experienced chest radiologists, were used as the gold standard. Images from 412 patients were used to train the model, whereas images from 83 patients were tested to obtain AI-based CO-RADS scores for each image. Six independent raters (one medical student, two residents, and three board-certified radiologists) evaluated the test images. Intraclass correlation coefficients (ICC) and weighted kappa values were calculated to determine the inter-rater agreement with the gold standard. The mean ICC and weighted kappa were 0.754 and 0.752 for the medical student and residents (taken together), 0.851 and 0.850 for the diagnostic radiologists, and 0.913 and 0.912 for AI, respectively. The CO-RADS scores calculated using our AI-based algorithm were comparable to those assigned by radiologists, indicating the accuracy and high reproducibility of our model. Our study findings would enable accurate reading, particularly in areas where radiologists are unavailable, and contribute to improvements in patient management and workflow.

    DOI: 10.3390/diagnostics12030738

    PubMed

    researchmap

  • Imaging of COVID-19: An update of current evidences. 査読 国際誌

    Shingo Kato, Yoshinobu Ishiwata, Ryo Aoki, Tae Iwasawa, Eri Hagiwara, Takashi Ogura, Daisuke Utsunomiya

    Diagnostic and interventional imaging   102 ( 9 )   493 - 500   2021年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been reported as a global emergency. As respiratory dysfunction is a major clinical presentation of COVID-19, chest computed tomography (CT) plays a central role in the diagnosis and management of patients with COVID-19. Recent advances in imaging approaches using artificial intelligence have been essential as a quantification and diagnostic tool to differentiate COVID-19 from other respiratory infectious diseases. Furthermore, cardiovascular involvement in patients with COVID-19 is not negligible and may result in rapid worsening of the disease and sudden death. Cardiac magnetic resonance imaging can accurately depict myocardial involvement in SARS-CoV-2 infection. This review summarizes the role of the radiology department in the management and the diagnosis of COVID-19, with a special emphasis on ultra-high-resolution CT findings, cardiovascular complications and the potential of artificial intelligence.

    DOI: 10.1016/j.diii.2021.05.006

    PubMed

    researchmap

  • Biodistribution and radiation dosimetry of the positron emission tomography probe for AMPA receptor, [11C]K-2, in healthy human subjects. 査読 国際誌

    Mai Hatano, Tomoyuki Miyazaki, Yoshinobu Ishiwata, Waki Nakajima, Tetsu Arisawa, Yoko Kuroki, Ayako Kobayashi, Yuuki Takada, Matsuyoshi Ogawa, Kazunori Kawamura, Ming-Rong Zhang, Makoto Higuchi, Masataka Taguri, Yasuyuki Kimura, Takuya Takahashi

    Scientific reports   11 ( 1 )   1598 - 1598   2021年1月

     詳細を見る

    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(学術雑誌)  

    [11C]K-2, a radiotracer exhibiting high affinity and selectivity for α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs), is suitable for the quantification of AMPARs in living human brains and potentially useful in the identification of epileptogenic foci in patients. This study aimed to estimate the radiation doses of [11C]K-2 in various organs and calculate the effective dose after injection of [11C]K-2 in healthy human subjects. Twelve healthy male subjects were registered and divided into two groups (370 or 555 MBq of [11C]K-2), followed by 2 h whole-body scans. We estimated the radiation dose of each organ and then calculated the effective dose for each subject. The highest uptake of [11C]K-2 was observed in the liver, while the brain also showed relatively high uptake. The urinary bladder exhibited the highest radiation dose. The kidneys and liver also showed high radiation doses after [11C]K-2 injections. The effective dose of [11C]K-2 ranged from 5.0 to 5.2 μSv/MBq. Our findings suggest that [11C]K-2 is safe in terms of the radiation dose and adverse effects. The injection of 370-555 MBq (10 to 15 mCi) for PET studies using this radiotracer is applicable in healthy human subjects and enables serial PET scans in a single subject.

    DOI: 10.1038/s41598-021-81002-3

    PubMed

    researchmap

  • Improved Diagnostic Accuracy of Bone Metastasis Detection by Water-HAP Associated to Non-contrast CT. 査読 国際誌

    Yoshinobu Ishiwata, Yojiro Hieda, Soichiro Kaki, Shinjiro Aso, Keiichi Horie, Yusuke Kobayashi, Motoki Nakamura, Kazuhiko Yamada, Tsuneo Yamashiro, Daisuke Utsunomiya

    Diagnostics (Basel, Switzerland)   10 ( 10 )   2020年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We examined whether water-hydroxyapatite (HAP) images improve the diagnostic accuracy of bone metastasis compared with non-contrast CT alone. We retrospectively evaluated dual-energy computed tomography (DECT) images of 83 cancer patients (bone metastasis, 31; without bone metastasis, 52) from May 2018 to June 2019. Initially, two evaluators examined for bone metastasis on conventional CT images. In the second session, both CT and CT images plus water-HAP images on DECT. The confidence of bone metastasis was scored from 1 (benign) to 5 (malignant). The sensitivity, specificity, positive predictive values, and negative predictive values for both modalities were calculated based on true positive and negative findings. The intra-observer area under curve (AUC) for detecting bone metastasis was compared by receiver operating characteristic analysis. Kappa coefficient calculated the inter-observer agreement. In conventional CT images, sensitivity, specificity, positive predictive value, and negative predictive value of raters 1 and 2 for the identification of bone metastases were 0.742 and 0.710, 0.981 and 0.981, 0.958 and 0.957, and 0.864 and 0.850, respectively. In water-HAP, they were 1.00 and 1.00, 0.981 and 1.00, 0.969 and 1.00, and 1.00 and 1.00, respectively. In CT, AUCs were 0.861 and 0.845 in each observer. On water-HAP images, AUCs were 0.990 and 1.00. Kappa coefficient was 0.964 for CT and 0.976 for water-HAP images. The combination of CT and water-HAP images significantly increased diagnostic accuracy for detecting bone metastasis. Water-HAP images on DECT may enable accurate initial staging, reduced radiation exposure, and cost.

    DOI: 10.3390/diagnostics10100853

    PubMed

    researchmap

  • Feasibility of prognosis assessment for cancer of unknown primary origin using texture analysis of 18F-fluorodeoxyglucose PET/computed tomography images of largest metastatic lymph node. 査読 国際誌

    Yoshinobu Ishiwata, Tomohiro Kaneta, Shintaro Nawata, Hitoshi Iizuka, Daisuke Utsunomiya

    Nuclear medicine communications   42 ( 1 )   86 - 92   2020年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    OBJECTIVE: Cancers of unknown primary origin cannot be staged using images, making the prognosis difficult. We attempted to predict prognosis of patients with unknown primary origin using tumour heterogeneity recently introduced in F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT). METHODS: Overall, 30 patients with unknown primary origin who underwent whole-body F-FDG PET/CT scans were retrospectively enrolled for texture analysis. The volume of interest was placed in the largest metastatic lymph nodes and conventional parameters and grey-level co-occurrence matrix (GLCM) were calculated. Statistical analysis of image-based variables was performed using Cox regression analyses. Patients were stratified into two groups based on cutoff values of GLCMentropy obtained using receiver operating characteristics (ROCs). Patients were analyzed, and overall survival (OS) was compared using Kaplan-Meier analysis. RESULTS: Univariate Cox regression analysis showed significant differences in prognosis for parenchymal organ metastasis (P < 0.01), GLCM homogeneity (P = 0.01), GLCMcontrast (P < 0.01), GLCMentropy (P < 0.01) and GLCMdissimilarity (P < 0.01). Multivariate Cox regression analysis showed a significant difference in reduced prognosis for GLCMentropy positive (P < 0.01). Stratification was performed based on the GLCMentropy cutoff value, determined using ROCs analysis, with smaller groups showing better OS. CONCLUSIONS: Despite previous difficulties in predicting prognosis in patients with unknown primary origin, F-FDG PET/CT texture features may enable stratification of prognosis. This could be useful for appropriate patient selection and management and help identify a subset of patients with favourable outcomes. These novel findings may be helpful for prognostication and improving patient care.

    DOI: 10.1097/MNM.0000000000001310

    PubMed

    researchmap

  • Cardiac overload resolved by resection of a large plexiform neurofibroma on both the buttocks and upper posterior thighs in a patient with neurofibromatosis type I: a case report. 査読 国際誌

    Taro Mikami, Yuki Honma-Koretsune, Yui Tsunoda, Shintaro Kagimoto, Yuichiro Yabuki, Jiro Maegawa, Takashi Terauchi, Shintaro Nawata, Hiroyuki Kamide, Yoshinobu Ishiwata, Tabito Kino, Teruyasu Sugano

    BMC surgery   20 ( 1 )   106 - 106   2020年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: A large plexiform neurofibroma in patients with neurofibromatosis type I can be life threatening due to possible massive bleeding within the lesion. Although the literature includes many reports that describe the plexiform neurofibroma size and weight or strategies for their surgical treatment, few have discussed their possible physical or mental benefits, such as reducing cardiac stress. In addition, resection of these large tumors can result in impaired wound healing, partly due to massive blood loss during surgery. CASE PRESENTATION: A 24-year-old man was diagnosed with neurofibromatosis type I and burdened with a large plexiform neurofibroma on the buttocks and upper posterior thighs. The patient was 159 cm in height and 70.0 kg in weight at the first visit. Cardiac overload was indicated by an echocardiography before surgery. His cardiac output was 5.2 L/min with mild tricuspid regurgitation. After embolism of the arteries feeding the tumor, the patient underwent surgery to remove the neurofibroma, followed by skin grafting. Follow-up echocardiography, performed 6 months after the final surgery, indicated a decreased cardiac output (3.6 L/min) with improvement of tricuspid regurgitation. Because the blood loss during the first surgery was over 3.8 L, malnutrition with albuminemia was induced and half of the skin graft did not attach. Nutritional support to improve the albuminemia produced better results following a second surgery to repair the skin wound. CONCLUSION: Cardiac overload may be latent in patients with neurofibromatosis type I with large plexiform neurofibromas. As in pregnancy, the body may compensate for this burden. In these patients, one stage total excision may improve quality of life and reduce cardiac overload. In addition, nutritional support is likely needed following a major surgery that results in either an extensive skin wound or excessive blood loss during treatment.

    DOI: 10.1186/s12893-020-00761-4

    PubMed

    researchmap

  • Visualization of AMPA receptors in living human brain with positron emission tomography. 査読 国際誌

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

    Nature medicine   26 ( 2 )   281 - 288   2020年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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

    DOI: 10.1038/s41591-019-0723-9

    PubMed

    researchmap

  • Quantification of temporal changes in calcium score in active atherosclerotic plaque in major vessels by F-18-sodium fluoride PET/CT 査読

    Yoshinobu Ishiwata, Tomohiro Kaneta, Shintaro Nawata, Ayako Hino-Shishikura, Keisuke Yoshida, Tomio Inoue

    EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING   44 ( 9 )   1529 - 1537   2017年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1007/s00259-017-3680-x

    Web of Science

    researchmap

  • Differences in sodium fluoride-18 uptake in the normal skeleton depending on the location and characteristics of the bone. 査読 国際誌

    Shintaro Nawata, Tomohiro Kaneta, Matsuyoshi Ogawa, Yoshinobu Ishiwata, Naomi Kobayashi, Ayako Shishikura-Hino, Keisuke Yoshida, Yutaka Inaba, Tomoyuki Saito, Tomio Inoue

    Nuklearmedizin. Nuclear medicine   56 ( 3 )   91 - 96   2017年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    AIM: The aim of this study was to evaluate the normal distribution of sodium fluoride-18 (NaF-18) and to clarify the differences in uptake according to location and the type of the bone using positron emission tomography (PET) / computed tomography (CT). METHODS: We retrospectively reviewed NaF-18 PET/CT images from 30 patients with hip joint disorders. PET/CT scans were performed 40 min after injection of approximately 185 MBq of NaF-18. To evaluate the relationship between the distribution of NaF-18 uptake and bone density, we compared the maximum standardised uptake values (SUVmax) on PET and the Hounsfield Units (HUs) on CT of the lumbar vertebra, ilium, and proximal and distal femurs. Regions of interests were defined both outside and inside the cortical bone to measure whole bone and cancellous bone only, respectively. RESULTS: The distribution of NaF-18 differed according to the skeletal site. The lumbar vertebra showed the highest SUVmax for both whole bone and cancellous bone, followed by the ilium, proximal femur, and distal femur. The bones differed significantly in SUVmax. The distal femur showed the highest HU, followed by the proximal femur, ilium, and vertebra. Profile curve analyses demonstrated that the cancellous bones showed higher SUVmax and lower HU than the cortical bones. CONCLUSIONS: Our results demonstrate the difference in NaF-18 uptake between cancellous and cortical bones, which may explain differences in uptake by location. NaF-18 uptake does not appear to be strongly correlated with bone density, but rather with bone turnover and blood flow.

    DOI: 10.3413/Nukmed-0867-16-12

    PubMed

    researchmap

▼全件表示

書籍等出版物

  • 臨床泌尿器科

    高野 祥子, 石渡 義之( 担当: 分担執筆 範囲: 特別措置病室とは何か)

    医学書院  2026年7月 

     詳細を見る

  • 臨床画像

    石渡 義之, 高野 祥子, 宇都宮 大輔( 担当: 分担執筆 範囲: 副甲状腺,副腎,神経芽腫(内用療法を除く))

    メジカルビュー社  2026年5月 

     詳細を見る

  • 産科と婦人科

    石渡 義之, 高野 祥子, 宇都宮 大輔( 担当: 分担執筆 範囲: PET)

    2026年3月 

     詳細を見る

  • 循環器画像診断 一問一答

    石渡 義之( 担当: 分担執筆 範囲: Q16 陽電子放射断層撮影(PET)の原理について教えてください. Q17 心臓PETのプロトコールについて教えてください.)

    Gakken  2025年8月 

     詳細を見る

  • 映像情報メディカル

    小野間恵乃, 石渡義之, 加藤 順二( 担当: 分担執筆 範囲: 脳SPECT検査の画質向上への取り組み)

    産業開発機構株式会社  2022年1月 

     詳細を見る

  • Clinical Neuroscience

    石渡 義之, 金田朋洋, 井上 登美夫( 担当: 分担執筆 範囲: DAT SPECT)

    中外医学社  2015年10月 

     詳細を見る

▼全件表示

MISC

  • ゾーフィゴ治療の生存率を予測するノモグラム作成

    北島一宏, 伊藤公輝, 菅剛, 尾谷知亮, 石渡義之, 河野由美子, 瀬古安由美, 鳥井原彰, 渡邊史郎, 細野眞, 久山順平

    核医学(Web)   60 ( Supplement )   2023年

     詳細を見る

  • ゾーフィゴ治療が良い適応となる患者像の検討

    北島一宏, 久山順平, 河原崇司, 菅剛, 尾谷知亮, 菅原茂耕, 河野由美子, 玉置幸久, 瀬古安由美, 石渡義之, 伊藤公輝, 鳥井原彰, 渡邊史郎, 細野眞, 山門亨一郎

    核医学(Web)   59 ( Supplement )   2022年

     詳細を見る

  • ゾーフィゴ治療が良い適応となる患者像の検討

    北島一宏, 久山順平, 河原崇司, 菅剛, 尾谷知亮, 菅原茂耕, 河野由美子, 玉置幸久, 瀬古安由美, 石渡義之, 伊藤公輝, 鳥井原彰, 渡邊史郎, 細野眞

    核医学(Web)   59 ( 1 )   2022年

     詳細を見る

  • ゾーフィゴ治療が良い適応となる患者像の検討

    北島一宏, 山本新吾, 久山順平, 河原崇司, 菅剛, 尾谷知亮, 菅原茂耕, 河野由美子, 玉置幸久, 瀬古安由美, 石渡義之, 伊藤公輝, 鳥井原彰, 渡邊史郎, 細野眞, 山門亨一郎

    泌尿器画像診断・治療技術研究会プログラム・抄録集   9th   2022年

     詳細を見る

  • Feasibility of prognosis development for cancer of unknown primary (CUP) using F-18-FDG PET/CT to determine intratumoral heterogeneity and total lesion glycolysis (TLG)

    Yoshinobu Ishiwata, Tomohiro Kaneta, Keisuke Yoshida, Ayako Hino, Tomio Inoue

    JOURNAL OF NUCLEAR MEDICINE   58   2017年5月

     詳細を見る

    記述言語:英語   掲載種別:研究発表ペーパー・要旨(国際会議)  

    Web of Science

    researchmap

講演・口頭発表等

  • 18F-FDG PET/CT texture analysisを用いた原発不明癌の予後層別化の可能性

    石渡 義之, 金田 朋洋

    Society of advanced medical imaging (SAMI)  2018年7月 

     詳細を見る

  • 非小細胞肺癌に対するNivolumab投与後の喀血に対し気管支動脈塞栓術を施行した一例.

    石渡 義之, 寺内 幹, 金田 朋洋

    放射線学会関東地方会  2018年6月 

     詳細を見る

    会議種別:ポスター発表  

    researchmap

  • Feasibility of prognosis assessment for cancer of unknown primary (CUP) using texture analysis of 18F-FDG PET/CT 国際会議

    石渡 義之

    世界核医学会  2018年4月 

     詳細を見る

    記述言語:英語   会議種別:ポスター発表  

    researchmap

  • FDG-PET/CTが診断に有用であった神経サルコイドーシスの1例

    安田尚史, 石渡義之, 金田朋洋

    日本核医学会関東甲信越地方会  2019年1月 

     詳細を見る

  • 押さえておきたい画像所見 招待

    石渡義之

    神奈川県診療放射線技術講習会  2019年1月 

     詳細を見る

    会議種別:公開講演,セミナー,チュートリアル,講習,講義等  

    researchmap

  • Improved diagnostic accuracy for the detection of bone metastasis with 256-row dual-energy computed tomography.

    Hieda Y, Ishiwata Y, Kaki S, Yamada K, Iizuka H, Yoshida K, Yamashiro T, Utsunomiya D

    欧州放射線学会  2020年7月 

     詳細を見る

  • CTにおけるCO-RADS 評価を可能とする深層学習モデルの構築.

    伊川瑞希, 石渡義之, 三浦賢太郎, 真上薫, 岸本真由子, 山城恒雄, 宇都宮大輔

    第61回神奈川県放射線医会総会  2021年10月 

     詳細を見る

  • Diagnostic performance of CO-RADS classification of COVID-19 pneumonia on chest CT in non-epidemic area.

    Kishimoto M, Ishiwata Y, Yamashiro T, Utsunomiya D

    第80回日本医学放射線学会総会,  2021年4月 

     詳細を見る

  • Qualitative and quantitative study of diagnostic performance of dual energy CT for bone metastases.

    Ishiwata Y, Hieda Y, Kishimoto M, Kaki S, Yamada K, Yamashiro T, Utsunomiya D

    第80回日本医学放射線学会総会,  2021年4月 

     詳細を見る

  • Zr-89を用いた国内初の臨床を目的としたBody Phantomの基礎的評価.

    尾川 松義, 西田 広之, 下田 三冬, 石渡 義之, 石川 栄二

    第60回日本核医学会学術総会  2020年11月 

     詳細を見る

  • Investigation of 123I-FP-CIT SPECT Imaging Time Reduction Using Artificial Intelligence

    Y. Ishiwata, H. Iizuka, K. Horie, A. Onoma, T. Yamashiro, M. Ogawa, D. Utsunomiya

    欧州核医学会  2022年10月 

     詳細を見る

  • Feasibility of prognosis development for cancer of unknown primary (CUP) using 18F-FDG PET/CT to determine intratumoral heterogeneity and total lesion glycolysis (TLG) 国際会議

    石渡 義之

    米国核医学会  2017年6月 

     詳細を見る

    記述言語:英語   会議種別:口頭発表(一般)  

    researchmap

  • The maximum blood-subtracted 18F-NaF activity (bsNaFmax) is a good predictor of calcified atherosclerotic plaque growth in the aorta. 国際会議

    石渡 義之

    米国核医学会  2016年6月 

     詳細を見る

    記述言語:英語   会議種別:ポスター発表  

    researchmap

  • Fever of unknown origin (FUO): evaluation of 50 cases with 18F-FDG PET/CT. 国際会議

    石渡 義之

    米国核医学会  2015年6月 

     詳細を見る

    記述言語:英語   会議種別:ポスター発表  

    researchmap

  • 非典型的な 18F-FDG PET/CT 所見を呈し,原発巣の特定に難渋した十二指腸神経内分泌癌 の一例

    伊藤 賢一, 石渡 義之

    日本核医学会 関東甲信越地方会  2018年7月 

     詳細を見る

  • 15 分でアップデート!前立腺がん診療における PSMA PET の役割と活用法 招待

    石渡 義之

    横浜放射線医会  2026年6月 

     詳細を見る

  • 医師による画像読影等におけるAI活用の促進 招待

    石渡 義之, 藤田

    内閣府規制改革推進会議 第9回 健康・医療・介護ワーキング・グループ  2026年2月 

     詳細を見る

  • AI-Assisted Double Reading versus Conventional Double Reading for Lung Cancer Detection on Screening Chest Radiographs: A Comparative Observational Study

    K. Horie, Y. Ishiwata, S. Matsushita, R. Fujita, T. Yamashiro, D. Utsunomiya

    欧州放射線学会  2026年3月 

     詳細を見る

  • 偶発所見を含む頭部CTにおける初学者と熟練者の読影手法の違い

    石渡 義之, 森 究, 浅原 涼子, 三角 優香, 山城 恒雄, 中村 潤, 宇都宮 大輔

    神奈川県放射線医会  2024年10月 

     詳細を見る

  • Targeted Radionuclide Therapy時代における核医学画像読影の役割と課題 招待

    石渡 義之

    神奈川県放射線医会  2025年10月 

     詳細を見る

  • Differences in Interpretation Techniques Between Novices and Experts in Head CT Imaging, Including Incidental Findings

    Y. Ishiwata, R. Asahara, Y. Misumi T., Yamashiro, J. Nakamura, D. Utsunomiya

    欧州放射線学会  2025年3月 

     詳細を見る

  • 婦人科悪性腫瘍におけるリンパ節転移の画像診断 招待

    石渡 義之

    産婦人科ジャーナルセミナー  2026年2月 

     詳細を見る

  • PRRTの経営戦略 招待

    石渡 義之

    Novartis Reality seminar  2025年11月 

     詳細を見る

▼全件表示

受賞

  • 優秀演題賞

    2024年10月   神奈川県放射線医会   偶発所見を含む頭部CTにおける初学者と熟練者の読影手法の違い

    石渡 義之

     詳細を見る

  • SAMIポスター優秀賞

    2018年7月   18F-FDG PET/CT texture analysisを用いた原発不明癌の予後層別化の可能性

    石渡 義之

     詳細を見る

  • 若手トラベルグラント

    2018年4月   日本核医学会   Feasibility of prognosis assessment for cancer of unknown primary (CUP) using texture analysis of 18F-FDG PET/CT

    石渡 義之

     詳細を見る

共同研究・競争的資金等の研究課題

  • 精神神経疾患の病態解明・診断のためのAMPA受容体PET薬剤[18F]K-40の脳内動態の解明

    研究課題/領域番号:26K02378  2026年4月 - 2029年3月

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    一條 貞満, 高橋 琢哉, 有澤 哲, 木村 裕一, 石渡 義之

      詳細を見る

    配分額:18330000円 ( 直接経費:14100000円 、 間接経費:4230000円 )

    researchmap

  • 視線計測技術を用いた標準的な核医学画像読影手法の確立

    研究課題/領域番号:25K19112  2025年4月 - 2030年3月

    日本学術振興会  科学研究費助成事業  若手研究

    石渡 義之

      詳細を見る

    配分額:4810000円 ( 直接経費:3700000円 、 間接経費:1110000円 )

    researchmap

  • 術前18F-フルシクロビン(アキュミン®)PET/CT 追加が照射野設計に及ぼす影響の検証―単施設後ろ向きフィージビリティ解析

    2025年4月 - 2027年3月

    日本メジフィジックス株式会社  研究者主導臨床研究支援プログラム 

      詳細を見る

    担当区分:研究代表者 

    researchmap

  • 画像診断支援AIを活用した胸部X線画像による肺癌スクリーニングの研究

    2025年4月 - 2027年3月

    大日本印刷  共同研究 

      詳細を見る

    担当区分:研究代表者 

    researchmap

  • 深層学習モデルを用いた脳核医学検査の画質改善および撮像時間短縮の検討

    研究課題/領域番号:20K16705  2020年4月 - 2023年3月

    日本学術振興会  科学研究費助成事業  若手研究

    石渡 義之

      詳細を見る

    配分額:4160000円 ( 直接経費:3200000円 、 間接経費:960000円 )

    今年度はまず昨年度作成した123I-イオフルパンの撮像時間短縮を目的とした深層学習モデル改良に取り組んだ.。昨年度はauto-encorderを用いたノイズリダクションを主体としたモデル構築を行っていたが、更なる改良として、GAN(Generative Adversarial Network:敵対的生成ネットワーク)を用いた深層学習モデルの構築を試みたが、昨年度作成したモデルより良い結果は得られなかった。
    さらに今年度は新型コロナウイルス肺炎に関する研究需要の増加により、新型コロナウイルス肺炎に関する深層学習の研究を行なった。PCR検査よりも迅速に新型コロナウイルス肺炎をより高感度で検出できるCT(computed tomography)検査は発熱外来でのルーチンとなっている。しかし医療逼迫の状況では画像診断を専門としない医師の読影も必要に迫られ、読影結果にばらつきが見られた。そこで新型コロナウイルス感染症疑いとして当院救急外来を受診し、CTを撮像された500症例を用いて、新型コロナウイルス肺炎らしさを5段階に定量化するモデル構築を科研費で購入したパソコンを用いて行なった。まず3名の放射線科医のコンセンサスリーディングにより各患者のCT画像に新型コロナウイルス肺炎らしさのスコアリングを行なった。約400例を用いて分類モデルの構築を行い、使用しなかった約90例を用いて画像診断初学者、画像診断上級者、深層学習のそれぞれで読影実験を行なった。その結果、画像診断上級者と深層学習モデルの読影結果は高い一致率を示した。この結果により深層学習を用いた画像診断により、新型コロナウイルス肺炎のリスクを画像診断医とほぼ同等にすることを可能とし、院内でのワークフローの改善に寄与しうる結果となった。

    researchmap

メディア報道

  • 期待高まる医療用RI(放射性同位元素) がんの治療や検査に利用 内服・注射で負担軽い 新聞・雑誌

    公明新聞社  公明新聞  2026年5月

     詳細を見る

  • DNP、横浜市立大とAI使ったX線画像分析 肺がん検診支援 インターネットメディア

    日本経済新聞社  日本経済新聞電子版  2026年3月

     詳細を見る

  • SPECT/CT装置Symbia Pro.spectaの使用経験とセラノスティクスにおける活用法 会誌・広報誌

    Siemens Healthineers Japan  Future of Healthcare Vol.15  2026年

     詳細を見る

  • 大日本印刷と横浜市立大学 AIを活用した肺がんスクリーニング研究を開始 インターネットメディア

    大日本印刷株式会社  DNPニュース  2025年10月

     詳細を見る

  • 大日本印刷、横浜市大とAIを活用した肺がんスクリーニング研究を開始 インターネットメディア

    日本経済新聞社  日本経済新聞電子版  2025年10月

     詳細を見る

  • CT検査における視線計測 インターネットメディア

    株式会社フォーカスシステムズ  取組み紹介  2022年10月

     詳細を見る

  • フォーカスシステムズ、AIを用いた新たな脳核医学検査手法の開発に着手 インターネットメディア

    産業開発機構  映像情報Medical  2021年9月

     詳細を見る

  • AIを用いた新たな脳核医学検査手法の開発に着手 インターネットメディア

    株式会社フォーカスシステムズ  プレスリリース  2021年9月

     詳細を見る

  • 横浜市立大学、AIを用いた認知症・パーキンソン病の検査手法の開発に着手 インターネットメディア

    株式会社アイスマイリー  2021年9月

     詳細を見る

  • 脳核医学領域初のAIを用いた検査時間短縮の共同研究を開始 インターネットメディア

    株式会社フォーカスシステムズ  プレスリリース  2020年7月

     詳細を見る

▼全件表示