Purpose or Case Report: Diseases of the coronary arteries are rare in children, but can present as unexpected catastrophic events without preceding symptoms. It is essential to identify patients at risk to prevent potentially serious cardiovascular events. Coronary CT angiography (CCTA) has been widely studied in adults, but its clinical applications are not well established in children.
Methods & Materials: Retrospective chart and image review of coronary artery computed tomographic angiography from 2016 - 2018 was conducted to assess 1) image quality, 2) unexpected events, and 3) radiation dose.
Results: A total of 32 cases of CCTA were performed in our hospital from January 2016 to May 2018 (from 0.5 to 30 years of age; median 12). Indications for CCTA include 1) congenital coronary anomalies (n = 12), 2) after arterial switch operation (n = 10), 3) other congenital heart disease (n = 6), and 4) miscellaneous (n = 4). All patients had a diagnostic echocardiogram. Although a few, initial studies were performed on a 64 slice scanner, most of the studies were performed using a 2 x 128 slice dual source scanner. High-pitch, prospectively gated, adaptive, prospectively gated, and dose modulated, retrospectively gated techniques were utilized depending upon the patients’ heart rhythms. Exposure parameters, kilovolt peak (kVp) and milliampere-seconds (mAs) were adjusted according to patient size and body habitus, as well as due to the presence of metallic chest implants. Three had suboptimal CT images due to an ectopic beat (1), hiccups (1), and a limited injection rate (1). Twenty nine cases (91%) showed expected diagnostic quality: 97% for coronary ostia and 91% for distal segments, superior to echocardiogram. Average/median radiation dose was 2.83/1.97 mSv, which was improved in 2018 (1.53/1.62 mSv) after protocol revision.
Conclusions: Coronary CTA provides more reliable image quality of the coronary ostia and distal segments than echocardiogram and delineates a distinct spatial relationship with extravascular structures that angiography cannot. The radiation dosage has been significantly reduced with proactive heart rate control by pre- and intra-procedural use of beta-blockers, as well as implementation of aggressive protocol dose reduction techniques. CCTA is a reliable and safe diagnostic modality in analyzing coronary anatomy in children.