320-ADCT(0.275 s/rot)による冠動脈CT血管造影におけるハーフ再構成，体動補正ソフト(APMC)およびフル再構成の限界(RR-PQ)時間

摘要

冠動脈computed tomography(CT)血管造影(coronary CT angiography:CCTA)では必要な位相だけをばく射するprospective electrocardiogram(ECG)-gated scanを積極的に使用することでretrospective ECG-gated scanよりも患者被ばくを低減できる.%Background: A clear coronary CT angiography (CCTA) can be obtained when temporal resolution (TR) is shorter than slow filling (SF) duration. The SF duration was calculated by the following equation: SF=-443+0.742 (RR-PQ). Although, the TR of half and full reconstruction using 320-ADCT (0.275 s/r) are known, the TR of automatic patient motion correction (APMC) reconstruction is not clear. The purpose of this study is to clarify the each minimum value of (RR-PQ) for acquiring a clear CCTA that was made by half, full or APMC reconstruction. Method: CCTA was performed in consecutive 345 (M/F=195/150, Age: 69±10 years) patients except for arrhythmia and the final heart rate (controlled by 3-blocker) ≥80 bpm using 320-ADCT (Aquilion ONE, 0.275 s/r). In all subjects, 3 CCTAs were generated by half, full, or APMC reconstruction at the same optimal phase. Image quality (A: excellent, B: acceptable, C: poor) was estimated by the consensus of three trained researchers. We classified (RR-PQ) into 15 groups by each 50 ms interval. Results: The A or B % prediction (y) significantly correlated (y=-240.08+0.401x, r=0.98， p=0.0006 in half, y=-238.26+0.378x, r=0.98, p=0.0001 in APMC, and y= -236.844-0.332x, r=0.97, p＜0.0001 in full reconstruction) with (RR-PQ) (x), respectively. Conclusion: The minimum values of (RR-PQ) for 95% prediction of A or B image quality were ≥836 ms in half, ≥881 ms in APMC, and ≥998 ms in full reconstruction.