Preoperative evaluation of the thoracic aorta using MRI and angiography.

The ability of ECG-gated magnetic resonance imaging (MRI) to evaluate disease of the thoracic aorta compared with angiography was prospectively assessed in 28 patients. MRI identified abnormalities in all patients, with confirmation at operation in 22 (79%) and by angiography alone in all 28. In 20 of the patients, MRI correctly diagnosed 20 of 21 aneurysms of the thoracic aorta (6 dissecting, 4 saccular, 10 fusiform), but 1 surgically proven fusiform aneurysm was categorized as an enlarged aortic dissection based on both MRI and angiographic findings. One dissection and 1 fusiform aneurysm were shown by MRI only. Coarctation of the aorta was identified in 4 patients. Ascending aortic enlargement and left ventricular hypertrophy were identified by MRI in 4 patients with aortic stenosis. In 7 patients (25%), MRI provided additional important information not shown by angiography and in 1 patient, the MRI findings resulted in a change in the surgical approach. In 14 of 28 patients (50%), angiography was necessary for definitive preoperative evaluation of the aortic valve, the coronary arteries, or the brachiocephalic vessels. MRI was a useful noninvasive supplement to angiography for the preoperative assessment of thoracic aortic disease.