Background: Despite the growing demand for amyloid PET quantification, practical challenges remain. As automated software platforms are increasingly adopted to address these limitations, we evaluated the reliability of commercial tools for Centiloid quantification against the original Centiloid Project method. Methods: This retrospective study included 332 amyloid PET scans (165 [¹⁸F]Florbetaben; 167 [¹⁸F]Flutemetamol) performed for suspected mild cognitive impairments or dementia, paired with T1-weighted MRI within one year. Centiloid values were calculated using three automated software platforms, BTXBrain, MIMneuro, and SCALE PET, and compared with the original Centiloid method. The agreement was assessed using Pearson’s correlation coefficient, the intraclass correlation coefficient (ICC), a Passing–Bablok regression, and Bland–Altman plots. The concordance with the visual interpretation was evaluated using receiver operating characteristic (ROC) curves. Results: BTXBrain (R = 0.993; ICC = 0.986) and SCALE PET (R = 0.992; ICC = 0.991) demonstrated an excellent correlation with the reference, while MIMneuro showed a slightly lower agreement (R = 0.974; ICC = 0.966). BTXBrain exhibited a proportional underestimation (slope = 0.872 [0.860–0.885]), MIMneuro showed a significant overestimation (slope = 1.053 [1.026–1.081]), and SCALE PET demonstrated a minimal bias (slope = 1.014 [0.999–1.029]). The bias pattern was particularly noted for FMM. All platforms maintained their trends for correlations and biases when focusing on subthreshold-to-low-positive ranges (0–50 Centiloid units). However, all platforms showed an excellent agreement with the visual interpretation (areas under ROC curves > 0.996 for all). Conclusions: Three automated platforms demonstrated an acceptable reliability for Centiloid quantification, although software-specific biases were observed. These differences did not impair their feasibility in aiding the image interpretation, as supported by the concordance with visual readings. Nevertheless, users should recognize the platform-specific characteristics when applying diagnostic thresholds or interpreting longitudinal changes.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but life-threatening pulmonary vascular disease caused by the presence of a prolonged thrombus in the pulmonary artery. CTEPH is a distinct disease entity classified as group 4 pulmonary hypertension according to the World Symposium on Pulmonary Hypertension. It is the only potentially curable cause of pulmonary hypertension. However, timely diagnosis and treatment are often hampered by nonspecific symptoms and signs and a lack of physician awareness regarding the condition. Thus, it is important to be familiar with the clinical features of CTEPH and the associated diagnostic processes. Herein, we cover the diagnostic approach for CTEPH using multimodal imaging tools in a clinical setting.

This study evaluates the clinical significance of the gastric emptying time (GET) in patients with functional dyspepsia (FD). This retrospective study included 89 patients who visited the clinic with indigestion between 2021 and 2022. FD was diagnosed and categorized into 3 subtypes: postprandial distress syndrome, epigastric pain syndrome, and overlap type, following the Rome IV criteria. GET was assessed using ^99mTc scintigraphy. The stomach remnant was measured 1 and 2 hours after ingesting a technetium-99m labeled egg, and the time required for the remnant to decrease by half (T_1/2) was calculated. Of the 89 patients studied, 46 were diagnosed with FD. The remaining 43 patients, who did not meet the Rome IV criteria, were included as the control group. Patients with FD exhibited a higher incidence of smoking, a higher body mass index, and a higher incidence of diabetes than the non-FD group. GET and T_1/2 did not show significant differences between the 2 groups (P = 0.240 and P = 0.126, respectively). However, the FD group exhibited a smaller gastric retention rate than the non-FD group at all time points. In the subtype analysis, GET and T_1/2 were not significantly different among the 3 subtypes (P = 1.000 and P = 0.173, respectively). Diabetes mellitus, current smoking status, elevated body mass index, and younger age were significantly associated with FD. GET did not significantly differ among FD patients or its subtypes, despite a lower gastric retention rate in FD patients.

Background/Objectives: Differentiating recurrent disease from postsurgical changes on ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) remains challenging in malignant pleural mesothelioma (MPM). This study aimed to characterize the temporal patterns of postsurgical FDG uptake and evaluate the diagnostic performance of FDG PET/CT for detecting recurrent disease after radical surgery. Methods: We retrospectively analyzed 91 postsurgical PET/CT scans from 45 patients with MPM who underwent extrapleural pneumonectomy (EPP; n = 29) or pleurectomy/decortication (P/D; n = 16). Scans were stratified into four postoperative time intervals: <6 months, 6 to <12 months, 12 to <24 months, and ≥24 months. FDG uptake in the postsurgical bed and local recurrent lesions was quantified using maximum standardized uptake value ratios normalized to the mediastinal blood pool and liver. Recurrence was confirmed by histopathology or follow-up imaging. Results: Postsurgical FDG uptake showed a time-dependent decline, with significantly lower uptake beyond 24 months postoperatively (p < 0.05). EPP patients demonstrated significantly higher postsurgical FDG uptake than P/D patients (p < 0.01). FDG PET/CT identified occult recurrence in 23.4% of CT-negative scans. Local recurrent lesions showed significantly higher FDG uptake than postsurgical changes across all postoperative intervals (p < 0.001). Conclusions: Postsurgical FDG uptake in MPM demonstrates a time-dependent decline, and surgical extent is an important determinant of background metabolic activity. Despite this variable background, FDG PET/CT demonstrated high diagnostic accuracy for detecting recurrent disease, including CT-occult recurrences. Incorporating surgical type and postoperative interval into PET/CT interpretation may improve diagnostic accuracy in postoperative MPM surveillance.