This retrospective study included 25 neonates with CHD who received a CT angiography (CTA) from 2009 to 2018. The examinations were performed as a high-pitch CTA (pitch 3.4, 80 kV) with manual contrast administration (1.5 ml/kg body weight) and fixed scan delay depending on the respective heart defect. Diagnosis, adverse events, radiation dose parameters, objective (contrast-to-noise ratio) and subjective (4-point Likert scale) image quality as well as diagnostic accuracy compared to intraoperative findings was assessed.
All examinations were diagnostically evaluable without adverse events. The median CT dose index volume (CTDIvol) was 0.50 mGy (range, 0.15-0.94), the median dose-length product was 8 mGy × cm (range, 3-17). The estimation of the effective dose by Monte Carlo simulation revealed lower median dose levels 0.66 mSv (range, 0.25-1.40 mSv) than previously published in comparable groups. All examinations achieved a very good mean image quality score of 1.2 ± 0.4 with only minimal image noise and mean contrast-to-noise ratio of 16.1 ± 7.0. Diagnostic accuracy was 100 % as cardiac anatomy revealed no new diagnoses or significant differences in the subsequent cardiac surgery.
Cardiac high-pitch CTA of neonates with CHD can be performed safely and dose-reducing without additional test bolus or bolus tracking scan. With very good image quality, it provides a detailed insight into the cardiac anatomy and thus enables a differentiated, noninvasive therapy planning.