Effect of a second-generation motion correction algorithm on image quality and measurement reproducibility of coronary CT angiography in patients with a myocardial bridge and mural coronary artery

Abstract

To determine the effect of second-generation motion correction (MC2) on image quality and measurement reproducibility of cardiac CT images in patients with a myocardial bridge and mural coronary artery (MB-MCA) compared to standard (STD) images without motion correction and with first-generation motion correction (MC1). A total of 66 patients with MB-MCA in the left anterior descending branch who underwent 256-detector CT with single-heartbeat acquisition were included. Images were reconstructed at 45% and 75% R-R intervals using STD, MC1, and MC2 algorithms. Image quality for MB-MCA was assessed by two observers on a four-point scale (1=poor and 4=excellent) and compared among STD, MC1, and MC2. Depth and length of MB, lumen area, and minimal diameter of MCA were measured and compared. At 45% R-R interval, image quality scores were 1.59±0.78, 2.21±0.97, and 3.21±0.62 for MCA, and 2.48±0.79, 2.76±0.75, and 3.58±0.58 for MB with STD, MC1 and MC2, respectively. At 75% R-R interval, these values were 2.26±0.60, 3.03±0.89, and 3.59±0.55 for MCA and 3.00±0.93, 3.17±0.83, and 3.80±0.44 for MB. Although MC1 was superior to STD in displaying MCA, there was no statistical difference between the two algorithms for MB (p>0.05). Compared with STD and MC1, MC2 statistically improved image quality and interpretability for both MCA and MB and had narrower limits in interobserver agreement for measurements at both 45% and 75% R-R intervals. MC2 improves CT image quality and measurement reproducibility in patients with MB-MCA compared to STD and MC1.