ObjectiveThe aim of this study was to explore the feasibility of using low dose radiation and low concentration contrast media in enhanced CT examinations in children with congenital heart disease. Materials and MethodsNinety patients with congenital heart disease were randomly divided into three groups of 30 patients each who underwent contrast-enhanced cardiac scans on a Discovery CT750 HD scanner. Group A received 270mgI/mL iodixanol, and group B received 320mgI/mL iodixanol contrast media and was scanned with prospective ECG triggering mode. Group C received 320mgI/mL iodixanol and was scanned with conventional retrospective ECG gating mode. The same weight-based contrast injection protocol was used for all three groups. Images were reconstructed using a 30% adaptive statistical iterative reconstruction (ASIR) algorithm and a 50% ASIR in groups A and B and a 30% ASIR in group C. The subjective and objective image quality evaluations, diagnostic accuracies, radiation doses and amounts of contrast media in the three groups were measured and compared. ResultsAll images in the three groups met the diagnostic requirements, with the same diagnostic accuracy and image quality scores greater than 3 in a 4-point scoring system. However, ventricular enhancement and the objective noise, signal-to-noise ratio, contrast-to-noise ratio and subjective image quality scores in group C were better than those in groups A and B (all P<.001). The effective radiation dose in groups A and B was 84% lower than that in group C (P<.001); group A received the lowest contrast dose (14% lower than that of groups B and C). ConclusionEnhanced CT scan images with low dose radiation and low concentration contrast media can meet the diagnostic requirements for examining children with congenital heart disease while reducing the potential risk of radiation damage and contrast-induced nephropathy.