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The aim of the study is to evaluate whether the prediction of anemia is possible using quantitative analyses of unenhanced cranial computed tomography (CT) with deep learning reconstruction (DLR) compared with conventional methods. Methods:This cross-sectional retrospective study included 116 participants (76 males; mean age, 66.7) who had hemoglobin (Hb) levels obtained within 24 hours of unenhanced cranial CT, which included 2 reconstruction methods: DLR and hybrid iterative reconstruction. Regions of interest were the confluence of sinuses (CoS) and the right and left transverse sinuses. In addition, edge rise distance of cerebrospinal fluid and venous was measured.Results: Spearman rank correlation coefficient demonstrated a positive association between Hb levels and sinus attenuation values. Among these, the CoS in DLR had the best correlation (r = 0.703, P < 0.001). For the prediction of anemia (Hb < 11 g/dL), the area under the curve of CoS in DLR (area under the curve = 0.874; 95% confidence interval, 0.798-0.949; P < 0.001) was the highest; however, there were no significant differences among reconstruction method and sinus. The attenuation values of DLR were significantly higher than those of hybrid iterative reconstruction ( P < 0.001, paired t test), and the differences between the 2 methods were 4.1 (standard deviation [SD], 1.6) for CoS, 5.2 (SD, 2.2) for right transverse sinuses, and 5.8 (SD, 2.4) for left transverse sinuses. The signal-to-noise ratio ( P < 0.001, paired t test) and edge rise distance ( P < 0.001, Wilcoxon signed rank test) of DLR was significantly higher. Conclusions:Higher CT attenuation values should be considered for predicting anemia based on brain DLR images.

Purpose Dopamine transporter single-photon emission computed tomography (DAT-SPECT) is an indispensable method for investigating Parkinson’s disease (PD). However, it comprises several confounding factors for consideration in a multicentre study. We aimed to assess the impact of the harmonization of multisite data on the differentiation between patients with PD and healthy elderlies in this multicentre cohort study. Methods We acquired a specific binding ratio (SBR)s of DAT-SPECT in 72 healthy elderlies (HCs) and 81 patients with PD (PDs). We assessed the effects of the following correction method for SBR: age and sex correction, correction for scanner differences by phantom scanning (phantom correction), a standardized operation for SBR computation (operation standardization), and a data-driven statistical method. We investigated the changes in the SBR and area under the receiver operating characteristic curve (ROC-AUC) for PD diagnostic accuracy. Results Without correction, the SBR yielded fair discrimination of PDs and HCs (Hedge’s g = 2.82 and ROC-AUC = 0.926). Age-sex correction exerted a moderate effect (g = 2.76 and ROC-AUC = 0.936). Of the multisite harmonization methods, the combination of phantom and operation correction displayed the largest changes (g = 4.32, ROC-AUC = 0.992), followed by data-driven correction (g = 3.99, ROC-AUC = 0.987). Conclusions Our findings demonstrated the usefulness of the multisite harmonization of DAT-SPECT in a multicentre cohort. Prospective correction with phantom scanning and operation standardization was ideal for the robustness and interpretability of the corrected values. The data-driven correction was another powerful method; however, the corrected value requires cautious interpretation.

Introduction: Myocardial flow reserve (MFR) derived from 13 N-ammonia positron emission tomography (PET) is used to predict adverse cardiac events in the patients with coronary artery disease (CAD). Right ventricular (RV) strain measured by magnetic resonance imaging (MRI) is used to evaluate RV function. This study aimed to evaluate the prognostic value of combined MFR and RV strain measured by hybrid 13 N-ammonia PET/MRI in patients with CAD. Methods: Sixty-one patients who underwent 13 N-ammonia PET/MRI were enrolled. MFR was calculated from dynamic acquisition of 13 N-ammonia PET under vasodilator stress with intravenous injection of adenosine. RV global longitudinal strain (GLS) was measured by wall motion tracking techniques in cine-mode MRI. The end points were defined as a composite of all-cause death, myocardial infarction, sustained ventricular arrhythmia, hospitalization due to decompensated heart failure, and revascularization. Results: At a follow-up of 2.8 ± 1.9 years, 21 events occurred. Kaplan-Meier analysis showed that the event-free rate was significantly lower in the group with MFR < 1.80 than that with MFR ≥ 1.80 (P < 0.001, Figure a). Additionally, the event-free rate was significantly lower in the group with RVGLS > –18.22% than that with RVGLS ≤ –18.22% (P = 0.025, Figure b). After dividing the patients into four groups by the median MFR and the median RVGLS, the event-free rate was lowest in the combined group of MFR < 1.80 and RVGLS > -18.22% than any other groups (P < 0.001, Figure c). In the Cox proportional hazard analysis, MFR and RVGLS were independent predictors of cardiac adverse events in the patients with CAD. Conclusion: The simultaneous assessment of MFR and RV strain by 13 N-ammonia PET/MRI revealed the feasibility of precise risk stratification for cardiac events in patients with CAD.