Normative computed tomography angiography values of the aortic root, aorta, and aortic arch in children.

Normative values for intracardiac and extracardiac vascular structures help in understanding normal growth and changes over time in children; this normative data is not currently available for ECG-gated computed tomography angiography (CTA). We sought to establish ECG-gated CTA-derived normative values for the aortic root, aorta, and aortic arch in children. Aortic root, ascending aorta, aortic arch, and descending aorta were measured in systole and diastole in 100 subjects who had ECG-gated CTA at our center between January 2015 and December 2020 and met our inclusion criteria. The allometric exponent (AE) for each parameter was derived, and the parameter/body surface area^AE (BSA^AE) was established using the previously described methods. Using this data, normalized mean, cross-sectional area, and standard deviation were calculated. Z-score curves were plotted in relation to the BSA for all measurements.

Conclusion: Our study reports systolic and diastolic ECG-gated CTA Z-scores along with normative curves in relation to BSA for the aortic root, aorta, and aortic arch in children.

What is known: • Normative data for intracardiac and extracardiac vascular structures in the pediatric population are available for echocardiography, cardiac MRI and non-ECG gated CTA. • Z-scores with standard deviations are commonly used in children, but SDs are not constant across body sizes due to heteroscedasticity.

What is new: • Allometric exponent was derived for each parameter and the parameter/body surface area (BSA) was established. • This is the first ECG-gated CTA study to provide normative en face systolic, diastolic diameters and cross-sectional areas along with Z-scores and normative curves for the aortic root, aorta and aortic arch in children.