MRI of congenital abnormalities of the great arteries.

ECG-gated MRI was performed at 0.3 T or 1.0 T in 19 patients, aged 6 years to 18 years, for suspected congenital abnormalities of the aorta (13 patients) or pulmonary artery (six patients). Seventeen of the patients were also evaluated by echocardiography, and 14 had angiograms. In 11 patients, MRI demonstrated lesions that echocardiography either failed to visualize or found inconclusive, including supravalvar aortic stenosis (one patient), coarctation of the aorta (three patients) hypoplastic aortic arch (one patient), and pulmonary artery hypoplasia or stenosis (six patients). MRI complemented echocardiographic diagnosis in four patients with Marfan's syndrome and in one with coarctation. One mild recurrent coarctation demonstrated angiographically was not visualized by MRI or echocardiography. The eight other angiographic studies of the aorta confirmed MRI findings. In all six MRI studies of the pulmonary arteries, obstructive lesions were revealed that had not been completely visualized on echocardiography or angiography. MRI is an excellent noninvasive method of depicting congenital abnormalities of the great arteries and may provide otherwise unobtainable information.