MR imaging of double outlet right ventricle.

Five patients with angiographically proven diagnosis of double outlet right ventricle (DORV) were studied with magnetic resonance (MR) imaging. Magnetic resonance was compared with angiography and echocardiography. Contiguous electrocardiographic-gated spin-echo images were acquired on a 0.35 T imager. Magnetic resonance was equivalent to echocardiography in demonstrating relative relationships of the great arteries with respect to each other, the relative positions of the great arteries with respect to the ventricular septal defect (VSD), and the caliber of the great vessels. It was comparable in visualization of the size and position of the VSD and position of the atrioventricular valves. Due to limited spatial resolution, MR failed to identify chordal straddle of a tricuspid valve and incorrectly interpreted pulmonary stenosis as pulmonary atresia. A small patch leak of an internal baffle was only visualized on angiography. We conclude that MR is superior to echocardiography in the noninvasive assessment of the spatial arrangement and caliber of the great vessels. As such, it is a useful adjunct to echocardiography in the noninvasive assessment of DORV.