Research Article: Ultra-low 70-kV cardiac CT angiography in neonates: a comparative dose-optimized approach with preserved image quality
Abstract:
To evaluate the feasibility of ultra–low tube voltage (70?kV) cardiac CT angiography (CTA) with weight-adapted iodine delivery in neonates and to compare image quality, coronary visibility, radiation exposure, and iodine delivery with those of a conventional 80-kV protocol.
This retrospective study included 125 neonates with congenital heart disease who underwent prospectively ECG-triggered cardiac CTA using a 256-row CT scanner. Patients were divided into an 80-kV group reconstructed with 50% adaptive statistical iterative reconstruction-V (ASIR-V) ( n =?61) and a 70-kV group reconstructed with 70% ASIR-V ( n =?64). Both protocols used standardized weight-adapted iodine delivery (450?mg I/kg). Subjective and objective image quality, coronary artery visibility, radiation dose, and iodine delivery were compared between groups.
Overall interobserver agreement for subjective image quality assessment was excellent ( ? =?0.815). Subjective image quality scores were comparable between the two groups across most coronary segments, with no significant differences in overall image quality (3.98?±?1.04 vs. 3.95?±?1.05, P =?0.545). Objective image quality parameters, including CT attenuation, image noise, signal-to-noise ratio, and contrast-to-noise ratio, also showed no significant differences between groups (all P >?0.05). Coronary artery visibility remained high in both groups, with overall visibility rates exceeding 89%. Importantly, distal coronary segments remained diagnostically assessable in approximately 75% of cases under the 70-kV protocol. Compared with the 80-kV protocol, the 70-kV protocol achieved a 24% reduction in effective radiation dose (0.32?±?0.05 vs. 0.42?±?0.06?mSv, P <?0.001) without increasing iodine delivery.
Ultra-low tube voltage (70?kV) cardiac CT with weight-adjusted iodine delivery is feasible for neonatal imaging and can substantially reduce radiation exposure while preserving coronary artery image quality and visibility. This approach may help achieve a more balanced trade-off among image quality, radiation dose, and contrast administration in neonatal cardiac CT examinations.
Introduction:
Congenital heart disease (CHD) is frequently associated with coronary artery anomalies, which have a reported prevalence of approximately 8.16% in children ( 1 ). Accurate delineation of the origin and course of the coronary arteries is critical for surgical planning in complex CHD ( 2 , 3 ). With advances in multidetector CT technology, cardiac CT angiography has emerged as an important noninvasive imaging modality for evaluating coronary anatomy in pediatric patients ( 4 ). However, accumulating epidemiological…
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