ABSTRACT
Objective:To investigate the reproducibility of whole-heart and volume-targeted balanced steady-state free precession (bSSFP) non-contrast MR coronary angiography (CMRA) for displaying coronary trunks.Methods:From February and September 2021, the whole-heart and volume-targeted CMRA examinations of 58 volunteers were prospectively and consecutively acquired in The First Affiliated Hospital of Fujian Medical University. Each volunteer underwent CMRA twice within a week. The subjective score, vessel-to-myocardium ratio (VMR), vessel-to-fat ratio (VFR), signal-noise ratio (SNR), and coronary corresponding coordinate was analyzed and extracted. Inter-observer, intra-observer and inter-scan consistency were evaluated by intraclass correlation coefficient (ICC), Bland-Altman analysis, Hausdorff Distance (HD), and Dice Similarity Coefficient (DSC).Results:The inter-observer and intra-observer consistencies of subjective scores, VMR, and VFR of the whole-heart and volume-targeted coronary artery images were excellent (ICC>0.76, P<0.001). The inter-scan VFR consistencies of RCA, LM, and LCX of whole-heart coronary scans were moderate (ICC=0.235, 0.264, 0.380, all P<0.05), while the consistencies of the remaining variables were good, (all ICCs>0.49, P<0.001). Bland-Altman method showed that most VMR, VFR, and SNR of two CMRA imaging were within the 95% limits of agreement. Whole-heart CMRA inter-and intra-observer mean HD was 1.79 (1.35, 3.25), 1.68 (1.09, 4.10), mean DSC was 0.96±0.04, 0.97±0.03. Volume-targeted CMRA inter-and intra-observer mean HD were 1.74 (1.63, 3.11), 1.74 (1.63, 1.98), and the mean DSC was 0.91±0.10, 0.95±0.05. The subjective score of raw images of the total artery trunk of volume-targeted CMRA [3.86 (3.68,4.00) vs. 3.80 (3.58,3.96) ], VMR [1.45 (1.27,1.58) vs. 1.22 (1.13,1.41) ], and VFR [7.36 (6.44,8.60) vs. 5.97 (4.97,6.64) ] were better than those of whole-heart CMRA (all P<0.05). The overall subjective score of whole-heart CMRA coronary trunk curved projection reformation was better than volume-targeted CMRA [3.75 (3.57, 3.88) vs. 3.63 (3.44, 3.71)] ( P<0.001). Conclusions:Whole-heart and volume-targeted bSSFP non-contrast CMRA represent good reproducibility and image quality in the main coronary artery of healthy volunteers. Both of the two methods have their advantages and complement each other.