Youichi Otomi, Takayoshi Shinya, Hideki Otsuka, Hiroto Kasai, Tomoki Matsushita, Yukiko Takaoka, Yuka Hiroshima, Tomoyasu Matsubara, Koji Fujita, Yukiko Tomioka, Masahito Nakataki, Shusuke Numata, Yuishin Izumi and Masafumi Harada : Serial amyloid PET demonstrates marked reduction in amyloid burden following donanemab treatment: a real-world cohort study, Japanese Journal of Radiology, 2026.
(Summary)
To evaluate changes in amyloid burden on serial amyloid PET before and after donanemab treatment in a real-world clinical cohort. This retrospective study included 20 consecutive patients who underwent serial amyloid PET before and after donanemab treatment. Quantitative analysis was performed using Centiloid values and tracer-specific standardized uptake value ratios (SUVr). Visual assessment was also performed to determine amyloid-positive or amyloid-negative status before and after treatment. Centiloid values significantly decreased from 52.3 ± 23.4 at baseline to - 5.6 ± 16.5 at follow-up, with a mean change of - 58.0 (p < 0.001). All patients showed a reduction in Centiloid values. In the flutemetamol group (n = 12), pons-referenced SUVr significantly decreased, while in the florbetapir group (n = 8), cerebellar-referenced SUVr also showed significant reductions (both p < 0.001). On visual assessment, 17 of 20 patients (85%) converted from amyloid-positive to amyloid-negative status after treatment. Serial amyloid PET demonstrated a substantial reduction in amyloid burden following donanemab treatment in this real-world cohort. Quantitative amyloid PET, particularly using Centiloid scaling, may be a useful tool for monitoring treatment response in clinical practice.
Manduukhai Badarchin, Youichi Otomi, Takayoshi Shinya, Hideki Otsuka, Yukiko Takaoka, Tomoki Matsushita, Tomoyasu Matsubara, Koji Fujita, Yukiko Tomioka, Masahito Nakataki, Yuishin Izumi, Shusuke Numata and Masafumi Harada : Comparative evaluation of CortexID and VIZCalc software in brain amyloid PET: a retrospective study of 116 cases, Annals of Nuclear Medicine, 40, 4, 425-433, 2025.
(Summary)
Quantitative analysis of amyloid positron emission tomography (PET) is increasingly applied in clinical and research settings; however, its consistency across software platforms remains uncertain. This study aimed to compare standardized uptake value ratio (SUVr) measurements obtained from CortexID Suite and VIZCalc, to evaluate their concordance with expert visual assessment, and to assess the concordance of Centiloid values derived from VIZCalc with the visual reference. We retrospectively analyzed 116 patients who underwent 18F-flutemetamol PET at a single institution. SUVr values were calculated using both CortexID Suite and VIZCalc, while Centiloid values were derived from VIZCalc only. Visual assessments were performed by two nuclear medicine physicians. Correlations among indices were examined using Pearson's correlation. Agreement between SUVr values was assessed with Bland-Altman analysis. Agreement with the non-independent visual reference was evaluated using receiver operating characteristic (ROC) analysis, and areas under the curves (AUCs) were compared with DeLong's test. SUVr values from CortexID and VIZCalc were strongly correlated (r = 0.986, p < 0.001), with a small mean difference of + 0.0397. Both platforms showed high concordance with the non-blinded visual assessment (AUC: 0.991 for CortexID; 0.989 for VIZCalc). Centiloid values also showed high agreement with the visual reference (AUC: 0.994) and were strongly correlated with SUVr values (r = 0.975 for CortexID; r = 0.965 for VIZCalc, p < 0.001). No significant difference was observed between platforms (p = 0.84). CortexID Suite and VIZCalc demonstrated high concordance with the non-blinded visual assessment and showed consistent quantitative trends. Both platforms can be reliably applied for amyloid burden quantification, provided that software-specific characteristics are appropriately considered.
Yukiko Takaoka, Noritake Matsuda, Hideki Otsuka, Ryosuke Kasai and Youichi Otomi : Utility of Quantitative Indices Derived from 67Ga-SPECT/CT in initial diagnosis and follow up of nephritis: A Case Report, Clinical Nuclear Medicine Open, 2, 4:e0055, 2025.
Takayoshi Shinya, Yuji Morine, Hiroki Ishibashi, Hironori Tanaka, Junichiro Hiraoka, Yukiko Takaoka, Yoichi Otomi, Hisanori Uehara, Koichi Tsuneyama, Tetsuji Takayama, Mitsuo Shimada and Masafumi Harada : Benign focal small bowel lesions : a review of the features on multiphasic multidetector computed tomography., The Journal of Medical Investigation : JMI, 72, 1.2, 1-7, 2025.
(Summary)
The detection of small bowel lesions and their discrimination from normal bowel tissue are the most elementary and important factors in the computed tomography (CT) diagnosis of focal small bowel lesions. The detection and characterization of small bowel lesions have recently improved with advances in CT technology. Post-contrast multiphasic multidetector CT (MDCT) aids in the assessment of the vascular features of focal small bowel lesions. Understanding the typical multiphasic MDCT features of focal small bowel lesions is valuable because CT features overlap, and the severity and associated complications need to be assessed. However, it is often difficult to accurately diagnose focal small bowel lesions on MDCT, and histological examination is required in many cases in clinical practice. Clinical applications have been recently developed to effectively utilize dual-energy CT in the image analysis of small bowel lesions. In addition, the challenge of evaluating small bowel lesions with the aid of artificial intelligence has attracted attention in recent years. This review aimed to provide a comprehensive guide for the relevant imaging features of different types of benign focal small bowel lesions. J. Med. Invest. 72 : 1-7, February, 2025.
Youichi Otomi, Nahomi Shono, Hajime Onishi, Ryota Mitsuhashi, Saya Matsuzaki, Yukiko Takaoka, Hideaki Enomoto, Yuko Sakamoto, Mihoko Sasahara, Takashi Abe, Takayoshi Shinya, Hideki Otsuka and Masafumi Harada : A reduced physiological 18 F-fluorodeoxyglucose uptake in the brain and liver caused by malignant lymphoma being deprived of the tracer, The Journal of Medical Investigation : JMI, 68, 1. 2, 181-185, 2021.
(Summary)
Purpose : To investigate whether or not the physiological brain and liver FDG uptake are decreased in patients with highly accelerated glycolysis lesions. Methods : We retrospectively analyzed 51 patients with malignant lymphoma. We compared the FDG uptake in the brain and liver of the patients with that in a control group. In 24 patients with a complete response (CR) or partial response (PR) to treatment, we compared the brain and liver uptake before and after treatment. Results : The maximum standardized uptake value (SUVmax) and total glycolytic volume (TGV) of the brain as well as the SUVmax and mean standardized uptake value (SUVmean) of the liver in malignant lymphoma patients were 13.1 ± 2.3, 7386.3 ± 1918.4, 3.2 ± 0.5, and 2.3 ± 0.4, respectively ; in the control group, these values were 14.9 ± 2.4, 8566.2 ± 1659.5, 3.4 ± 0.4, and 2.5 ± 0.3, respectively. The SUVmax and TGV of the brain and the SUVmean of the liver in malignant lymphoma patients were significantly lower than the control group. The SUVmax and TGV of the brain after treatment were significantly higher than before treatment. Both the SUVmax and SUVmean of liver after treatment were higher than before treatment, but not significant. Conclusion : A decreased physiological brain and liver FDG uptake is caused by highly accelerated lesion glycolysis. J. Med. Invest. 68 : 181-185, February, 2021.