Purpose: To assess the accuracy of MR angiography alone in screening for vascular stenosis of the common carotid bifurcation.
Methods: Two hundred two common carotid bifurcations in 101 patients were evaluated with MR angiography and selective contrast arteriography. A two-dimensional time-of-flight pulse sequence was used to obtain sequential transverse images through the common carotid bifurcations. These images were reprojected with a maximum intensity pixel ray-tracing algorithm. Both examinations were blindly graded as either normal or mildly stenotic (0%-29%), moderately stenotic (30%-69%), severely stenotic (70%-99%), or occluded.
Results: Of the 202 common carotid bifurcations, 119 were classified as normal-mild stenosis by contrast arteriography. In this category, MR angiography correctly identified 114 of these as normal to mild stenosis. Among 21 common carotid bifurcations graded as moderate stenosis by arteriography, 15 were correctly graded as moderate by MR angiography. Among 45 common carotid bifurcations graded as severe stenosis by arteriography, 41 of these were correctly graded as severe by MR angiography. There were 17 complete occlusions which were all correctly graded by MR angiography.
Conclusion: MR angiography with its high rate of agreement with contrast arteriography can be regarded as an accurate screening method of the common carotid bifurcation.