Vascular imaging with MRI: inadequacy in Takayasu's arteritis compared with angiography.

Magnetic resonance imaging (MRI) and angiography were compared in a prospective and blinded fashion in 10 consecutive patients with Takayasu's arteritis to evaluate the ability of MRI to detect vascular abnormalities in the large arteries of the thorax and abdomen. Only the aorta and its major branches were studied. MRI was performed with a 0.5-T superconducting instrument and a body coil. Overlapping cuts, oblique views, and cardiac gating were used. Using angiography as the gold standard, MRI correctly identified all lesions in three patients, gave false-positive findings in two patients, and gave false-negative findings in five patients. In the latter five patients, MRI missed areas of major pathology in proximal arch vessels. MRI sensitivity was only 38% with a patient-by-patient analysis and 54% with a lesion-by-lesion analysis. The visualization of specific arteries with MRI was compared to visualization with angiography, and was markedly inferior in all vessels except the aorta, the innominate artery, and the common iliac arteries. It appears that with current equipment and technology, MRI is inadequate as a screening examination or for detailed evaluation of arterial disease other than the aorta except in highly selected cases.