Abstract：Objective To investigate the effect of application of snapshot freeze (SSF) motion correction
algorithm on the image quality of coronary CT angiography (CCTA) on optimal monochromatic energy
level. Methods Thirty consecutive patients who underwent coronary CTA without heart rate control
were selected. All of the CCTA images were reconstructed by the means of both STD and SSF motion
correction, which was about 85% period of image reconstruction. An experienced radiologist made
use of post-processing workstation to measure the value of CT about blood vessel the noise of image.
Comparisons of variables about the CT value of the major blood vessels, noise, SNR and CNR were
performed with t test.Image quality and interpretability of STD and SSF reconstructions were compared.
CCTA images were interpreted with 5-points score system by two experienced radiologists. The image
qualities were assessed on per-artery and per-segment level,and interpretability was performed on persegment,
per-artery, and per-patient levels. Comparisons of variables were performed with paired
Wilcoxon rank sum test. Results The STD and SSF reconstructions of three main vessels showed no
significant differences in CT value. The image qualities were higher with the use of SSF reconstructions
than STD reconstructions on LM [(4.7±0.5), (4.9±0.3), Z=-2.232a, P=0.026], LAD [(4.4±0.4),
(4.5±0.4), Z=-2.68a, P=0.007], LCX [(4.1±0.6), (4.3±0.4), Z=-2.668a, P=0.008], and RCA [(3.5±0.6),
(4.5±0.4), Z=-4.785a, P=0] levels. Conclusion The use of SSF motion correction algorithm improved
image quality and interpretability or coronary CTA.
