Feasibility study of coronary CT angiography in single cardiac cycle in patients with high heart rate using 256-row detector CT

Abstract

Objective To investigate the feasibility of coronary CT angiography in single cardiac cycle and to analyze the image quality and radiation dose in patients with high heart rate(HR) using 256-row detector CT. Methods Ninety-two consecutive patients between October and November 2015 who were suspected coronary artery disease underwent coronary CT angiography (CCTA) were enrolled, which was performed with a 256-row detector CT (Revolution CT, GE Healthcare) using prospective ECG-triggered volume CCTA within a single cardiac cycle with snapshot freeze (SSF) technique. The patients were grouped by HR during CT scans: group A (80—89 bpm, n=56), group B (90—99 bpm, n=20), and group C (≥100 bpm, n=16). Image quality was compared before and after using SSF technique reconstructions in seventy-four patients. The image quality of coronary artery was evaluated blindly by 2 experienced radiologists using a four-point scale based on the 18-segment model according to the Society of Cardiovascular Computed Tomography guidelines. The differences in age, body mass index, heart rate and CT dose index volume, effective dose(ED) among the three groups were compared by using ANOVA analysis or Kruskal-Wallis test, the image quality and interpretability using χ2 test. Comparisons of image quality between standard and SSF were performed with paired Wilcoxon rank sum test. Kappa coefficient was used to test inter-observer agreement. Results A total of 1 065 coronary artery segments, 98.97% (1 054/1 065) met the requirements for diagnosis. No significant difference was found (χ2=1.274, P=0.563) for the diagnostic image quality of coronary artery segments among the 3 groups with 98.64% (651/660), 99.57%(232/233), 99.42% (171/172), respectively. Significant difference (χ2=68.811, P 0.05). Conclusions Single cardiac cycle scan is feasibility for coronary CT angiography in patients with high heart rate using 256-row detector CT. This scan mode can maintain the diagnostic image quality with low radiation dose. SSF technique can improve the image quality. Key words: Heart rate; Coronary vessel; Tomography, X-ray computed; Radiation dosage