Abstract:Objective This study tried to evaluate the coincidence of selecting optimal cardiac phase between the smart phase
technique and manual selection in coronary CTA (CCTA) examinations. Methods A total of 100 patients with suspected coronary
artery disease who underwent CCTA examinations were included in this study. Smart phase technique and manual selection were
used to select a group of axial images with optimum cardiac phase for each patient. The optimum cardiac phases selected by these
two ways (coincidence: phase difference ≤±2%; noncoincidence: phase difference >±2%) were compared. The body mass index,
heart rate, CT value, objective noise, dose-length product values were recorded. Results The results of auto selection of 83 cases
(83%) were in accordance with the manually selected results. Among the 17 cases with differences between the auto and manual
selection, 8 cases only had subtle differences which could meet the diagnostic requirement, while 9 cases failed to meet the diagnostic
requirement (3 cases with high heart rate, 2 cases with atrial fibrillation and 4 cases with premature beats). In the 9 cases with failed
diagnostic requirement, each had at least one major coronary branch reconstruction that failed to meet the diagnostic requirement.
However, after manual selection, the images could be used for diagnosis. Conclusion The selecting optimal cardiac phase between
the smart phase technique and manual selection was in good coincidence with CCTA examinations. Smart phase technique could
greatly simplify 3D reconstruction workflow, increase efficiency and provide good coronary CTA reconstruction results.