Background:Accurate assessment of intra-as well as extra-cardiac malformations and radiation dosage concs are especially crucial to infants and children with interrupted aortic arch (IAA).The purpose of this study is to investigate the value of prospective electrocardiogram (ECG)-triggered dual-source computed tomography (DSCT) angiography with low-dosage techniques in the diagnosis of IAA.Methods:Thirteen patients with suspected IAA underwent prospective ECG-triggered DSCT scan and transthoracic echocardiography (TTE).Surgery was performed on all the patients.A five-point scale was used to assess image quality.The diagnostic accuracy ofDSCT angiography and TTE was compared with the surgical findings as the reference standard.A nonparametric Chi-square test was used for comparative analysis.P＜0.05 was considered as a significant difference.The mean effective radiation dose (ED) was calculated.Results:Diagnostic DSCT images were obtained for all the patients.Thirteen IAA cases with 60 separate cardiovascular anomalies were confirmed by surgical findings.The diagnostic accuracy of TTE and DSCT for total cardiovascular malformations was 93.7％ and 97.9％ (P＞0.05),and that for extra-cardiac vascular malformations was 92.3％ and 99.0％ (P ＜ 0.05),respectively.The mean score of image quality was 3.77 ± 0.83.The mean ED was 0.30 ± 0.04 mSv (range from 0.23 mSv to 0.39 mSv).Conclusions:In infants and children with IAA,prospective ECG-triggered DSCT with low radiation exposure and high diagnostic efficiency has higher accuracy compared to TTE in detection of extra-cardiac vascular anomalies.