['To determine whether delayed-enhancement magnetic resonance imaging can identify fibrous tissue associated with patch reconstructions in postoperative patients with congenital heart disease. Additionally, to determine whether fibrous structures not directly related to the surgical reconstruction exhibited delayed enhancement.', 'Seventy-three patients underwent magnetic resonance imaging. Studies were retrospectively reviewed for the presence of delayed enhancement along the ventricular outflow tracts, cardiac valves, and where available, the ascending aorta. Three groups were identified. Group A patients (n = 34) underwent right ventricular outflow tract reconstruction and ventricular septal defect patch closure. Group B patients (n = 33) had never undergone cardiac surgery. Group C patients (n = 6) had functional single ventricle and underwent Norwood reconstruction.', 'In group A, 31 of 34 patients had delayed enhancement of the right ventricular outflow tract, and 14 of 34 had delayed enhancement of the ventricular septal defect patch (P < .001). In group B (n = 33), 1 patient with arrhythmogenic right ventricular dysplasia had delayed enhancement limited to the right ventricular outflow tract. The remainder had no delayed enhancement of either outflow tract. Delayed enhancement of the aortic valve and ascending aorta was observed in 13 of 34 (P = .002) and 10 of 26 (P = .05) group A patients, respectively, compared with 2 of 33 and 3 of 24 group B patients. In group C, delayed enhancement of the Norwood reconstruction was observed in 5 of 6 patients (P = .002).'] Does delayed-enhancement cardiovascular magnetic resonance identify fibrous tissue in children after surgery for congenital heart disease?