Application of dual-energy CT with prospective ECG-gating in cardiac CT angiography for children: Radiation and contrast agent dose

Abstract

ObjectiveThis research aimed to investigate the feasibility of utilizing dual-energy CT virtual monoenergetic images (VMI11VMI:virtual monoenergetic images.) with prospective electrocardiogram (ECG22ECG:electrocardiogram.) gating for reducing radiation and contrast agent doses in pediatric patients with congenital heart disease (CHD33CHD:congenital heart disease.). MethodsThere were 100 pediatric patients with CHD included in this study. Group A (n = 50) underwent dual-energy scanning with prospective ECG-gating, and group B (n = 50) underwent conventional scanning with retrospective ECG-gating. Comparative analysis of CT values of lumen, objective image quality assessment, subjective image quality evaluations, and diagnostic efficacy were performed. ResultsCT values, image noise, signal-to-noise ratio (SNR44SNR:signal-to-noise ratio.), and contrast-to-noise ratio (CNR55CNR:contrast-to-noise ratio.) were significantly affected by the VMI energy level, and they all increased with decreasing energy levels (P > 0.05). Combining subjective evaluation, the 45 keV VMI was considered the optimum image in group A. The 45 keV VMI exhibited higher CT values of lumen compared to conventional scanning images (P < 0.003 ∼ 0.836), but meanwhile, the image noise was also higher in the 45 keV VMI (P = 0.004). Differences between the two groups in SNR, CNR, and diagnostic accuracy were not statistically significant. Compared to group B, the 45 keV VMI showed fewer contrast-induced artifacts (P < 0.001) and higher image quality score (P = 0.037). Group A had a 64 % reduction in radiation dose and a 40 % decrease in iodine dose compared to group B. ConclusionThe combination of dual-energy CT with prospective ECG-gating reduces radiation and iodine doses in pediatric patients with CHD. The 45 keV VMI can provide clinically acceptable image quality while declining contrast agent artifacts.