Magnetic resonance imaging: evaluation of palliative systemic-pulmonary artery shunts

Eleven patients with a total of 17 palliative systemic-pulmonary artery shunts underwent evaluation by electrocardiogram-gated magnetic resonance imaging (GMRI). GMRI successfully imaged 11 of 17 shunts (65%), including five of nine Blalock-Taussig shunts, four of six Glenn shunts, and both aortopulmonary shunts. All shunts except for the Waterston were imaged on coronal sections during end-systole. The single Waterston shunt was seen on sagittal and transverse scans. Shunt localization and identification were facilitated by obtaining multiple, contiguous sections through the body. Glenn shunts could be imaged entirely in one section, although multiple sections were required to locate the correct plane. Blalock-Taussig shunts generally required multiple sections to image different segments of the shunt. Both aortopulmonary shunts were seen as direct side-to-side connections of the aorta and pulmonary artery. GMRI permitted assessment of the size, course, patency, and distribution of systemic-pulmonary artery shunts as well as the size and morphology of the proximal pulmonary arteries. We conclude that GMRI is a useful, noninvasive method for imaging the anatomy of systemic-pulmonary artery shunts.