The SnapShot Freeze Algorithm Improves Image Quality of Coronary Computed Tomography Angiography Using High-Resolution Wide-Detector CT

Abstract

Objective: The aim of this study was to investigate the effect the motion-correction reconstruction algorithm SnapShot Freeze (SSF) on the diagnostic performance of coronary computed tomography angiography (CCTA) using high-resolution, wide-detector CT. Methods: CCTA was performed using an electrocardiography-triggered auto-gating protocol in 62 patients. All images were reconstructed using both standard algorithm and motioncorrection algorithm (SSF). According to the American Heart Association (AHA) guidelines for coronary angiography, the coronary artery was divided into 15 segments. The coronary artery segments were evaluated using a 4-point Likert scale to determine the image quality. Arteries with a score greater than 1 were further evaluated by two expert radiologists blinded to conditions. The diagnostic performance of SSF was compared in the patients with high heart rate (HR ≥ 75 beats per minute) compared to low HR (< 75 beats per minute). Results: At the segmental level, the Likert score for segments 1–4 and 6–14 were higher in SSF compared to standard algorithm (p < 0.05). The proportion of images that was improved by SSF was greater for the high HR systolic phase imaging (66.7%) than for the low HR diastolic phase imaging (34.3%, p < 0.05). Conclusion: The SSF algorithm improves coronary CTA images acquired using a 256-row wide detector CT, compared to standard algorithm, particularly in patients with high HR.