ObjectiveThis study aims to compare the value of a gadolinium contrast-enhanced 1.5-T three-dimensional (3D) steady-state free precession (SSFP) sequence with that of a noncontrast 3D SSFP sequence for magnetic resonance coronary angiography in a pediatric population.Materials and methodsSeventy-nine patients from 1 month to 18 years old participated in this study. A 3D SSFP coronary MRA at 1.5-T was applied before and after gadolinium-diethylenetriaminepentaaceticacid (DTPA) injection. The detection rates of coronary arteries and side branches were assessed by McNemar'sχ2test. The image quality, vessel length, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the coronary arteries were analyzed by the Wilcoxon signed-rank test. The intra- and interobserver agreements were evaluated with a weighted kappa test or an intraclass correlation efficient test.ResultsA contrast-enhanced scan detected more coronary arteries than a noncontrast-enhanced scan in patients under 2 years old (P< 0.05). The SSFP sequence with contrast media detected more coronary artery side branches in patients younger than 5 years (P< 0.05). The image quality of all the coronary arteries was better after the injection of gadolinium-DTPA in children younger than 2 years (P< 0.05) but not significantly improved in children older than 2 years (P> 0.05). The contrast-enhanced 3D SSFP protocol detected longer lengths for the left anterior descending coronary artery in children younger than 2 years and the left circumflex coronary artery (LCX) in children younger than 5 years (P< 0.05). SNR and CNR of all the coronary arteries in children younger than 5 years and the LCX and right coronary artery in children older than 5 years enhanced after the injection of gadolinium-DTPA (P< 0.05). The intra- and interobserver agreements were high (0.803–0.998) for image quality, length, SNR, and CNR of the coronary arteries in both pre- and postcontrast groups.ConclusionThe use of gadolinium contrast in combination with the 3D SSFP sequence is necessary for coronary imaging in children under 2 years of age and may be helpful in children between 2 and 5 years. Coronary artery visualization is not significantly improved in children older than 5 years.