Image Quality and Radiation Doses of Volumetric 320-row Computed Tomography Angiography with Prospective Electrocardiogram-gating in the Assessment of Coronary Arteries in Neonates and Infants

Background: Diagnostic imaging of coronary arteries is required in neonates and infants suspected of congenital or acquired coronary artery anomalies and in pre- and postoperative assessment of complex congenital heart diseases (CHD).

Aim: Our study aimed to evaluate the image quality of volumetric 320-row computed tomography angiography (CTA) with prospective electrocardiogram (ECG)-gating for coronary arteries in neonates and infants with heart diseases, analyze factors influencing image quality and assess a radiation dose related to the procedure.

Methods: The study included 110 CTA performed in neonates and infants with CHD.

Results: CTA was performed in 37 girls and 73 boys at a median (interquartile range [IQR]) age of 3.0 (0.5-5.0) months, median (IQR) body weight of 5 (3.66-6.5) kg, and median heart rate (HR) of 133 (92-150) beats per minute. The orifices of the left coronary artery were visible in 100% of CTA, the orifices of the right coronary arteries were visible in 96%, whereas all coronary segments were assessable in 45% of CTA. Patients with non-diagnostic segments were significantly younger, median (IQR) age of 2.0 (0.21-5.00) months, had lower body weight of 4.6 (3.45-6.07) kg and faster HR of 136.5 (120-150) beats per minute (P <0.05) than patients with diagnostic image quality in all segments (4.0, 2-6 months, 6.0, 4.2-7 kg, and 130; 110-150 beats per minute, respectively; P <0.05).

Conclusions: CTA performed with volumetric 320-row prospective ECG-gating allows for good visibility of the coronary arteries with an acceptable radiation dose. Children aged >15 days, with body weight >4.85 kg and HR <130 beats per minute are good candidates for excellent quality non-invasive CTA of all segments of coronary arteries.