Depiction of the native coronary arteries during ECG-triggered High-Pitch Dual-Source Coronary Computed Tomography Angiography in children: Determinants of image quality

Objective: Assess the image quality of ECG-triggered High-Pitch Dual-Source CTA for the evaluation of native coronaries in children. Materials and methods: Between August 2014 and September 2017, 45 children with morphologically normal cardiac chambers had cardiac prospective ECG-triggered High-Pitch Dual-Source CTA. Two pediatric radiologists blinded to clinical data, independently reviewed each case. The coronary arteries were evaluated using a four-point scale quality score according to the coronary segment. Attenuation, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured using values from the air, inter-ventricular septum and ascending aorta at the level of the sinuses of Valsalva. Results: 225 coronary segments were assessed showed a mean score of 2.40 +/- 0.73, 94.2% had diagnostic image quality. The best and worst average quality were seen in segment 5 and 2, respectively. Inter-observer agreement was moderate for all segments except for segment 1, which was excellent. Worse quality scores were significantly associated with younger patients and low body mass index as well as with higher heart rates in all segments. The mean observed heart rate and BSA in patients with diagnostic image quality were below 77 bpm and over 1.4 m(2) respectively. There is no significant association between attenuation, SNR and CNR with image quality. Conclusions: Prospective ECG-triggered High-Pitch Dual-Source Computed Tomography Angiography achieves consistent and diagnostic image quality for coronary artery assessment at a low effective dose in pediatric patients.