Wen B, et al. - During this study, experts gauged the image quality and radiation dose of computed tomography (CT) coronary angiography using a 256-row detector CT scanner in a single cardiac cycle in patients with atrial fibrillation (AF). The diagnostic image quality was achieved via CT coronary angiography with use of a new 256-row detector CT in a single cardiac cycle, however, with lower radiation dose in patients with AF. No notable effect of heart rate or HR variability (HRV) was discovered on image quality.