Objective To explore the clinical application of low-dose dual-source CT (DSCT) angiography in diagnosis of coronary artery fistulas (CAF) in children. Methods A total of 22 patients [mean age (3.2 ± 1.5) yrs,age range 1.2-6.0 yrs; male 12,female 10] with CAF who underwent DSCT angiography under free breathing were retrospectively reviewed.Surgery was performed in 9 patients,and transcatheter closure in 13 patients.The diagnostic accuracy of DSCT was evaluated based on the surgical or conventional cardiac angiography (CCA) findings.The subjective image quality was evaluated on a fourpoint scale by two radiologists.Radiation dose values were recorded.Interobserver agreement of subjective image quality grading was assessed by using Kappa statistics.Results All images were diagnosable.The average subjective image quality score was 2.6 ± 0.7.Two radiologists made good agreement (K =0.75,P < 0.05).Twenty-five coronary artery fistulas in all patients were clearly displayed on DSCT images with accuracy of 100%.CAF arose from right coronary artery in 13(59.1%) cases,from left coronary artery in 8(36.4%) cases and from dual coronary arteries in 1 (4.5%) case.There were 4 patients associated with coronary artery aneurysms.The mean dose-length product (DLP) was (25 ± 4) mGy · cm resulting in an estimated mean effective radiation dose of (0.25 ± 0.07)mSv.Conclusion Low-dose DSCT angiography provides accurate and reliable diagnosis for coronary artery fistulas in children. Key words: Coronary vessels ; Vascular fistula ; Tomography, X-ray computed ; Radiation dosage; Child