Coronary artery visibility in free-breathing young children on non-gated chest CT: impact of temporal resolution.

ABSTRACT

BACKGROUND: Dual-source CT allows scanning of the chest with high pitch and high temporal resolution, which can improve the detection of proximal coronary arteries in infants and young children when scanned without general anesthesia, sedation or beta-blockade. OBJECTIVE: To compare coronary artery visibility between higher and standard temporal resolution. MATERIALS AND METHODS: We analyzed CT images in 93 children who underwent a standard chest CT angiographic examination with reconstruction of images with a temporal resolution of 75 ms (group 1) and 140 ms (group 2). RESULTS: The percentage of detected coronary segments was higher in group 1 than in group 2 when considering all segments (group 1 27%; group 2 24%; P = 0.0004) and proximal segments (group 1 37%; group 2 32%; P = 0.0006). In both groups, the highest rates of detection were observed for the left main coronary artery (S1) (group 1 65%; group 2 58%) and proximal left anterior descending coronary artery (S2) (group 1 43%; group 2 42%). Higher rates of detection were seen in group 1 for the left main coronary artery (P = 0.03), proximal right coronary artery (P = 0.01), proximal segments of the left coronary artery (P = 0.02) and proximal segments of the left and right coronary arteries (P = 0.0006). CONCLUSION: Higher temporal resolution improved the visibility of proximal coronary arteries in pediatric chest CT.