Current role of cerebral angiography in the diagnosis of cerebrovascular diseases.

The role of cerebral angiography in the diagnosis of cerebrovascular disease is currently being questioned because of the increasing availability of MR angiography. The purpose of this essay is to place the use of cerebral angiography in perspective in light of these new developments. In patients with atherosclerotic cerebrovascular disease, MR angiography can almost entirely supplant cerebral angiography as a screening procedure in the evaluation of the carotid bifurcation. However, detection of "pseudoocclusion" still requires cerebral angiography for accurate diagnosis. Atherosclerotic stenosis or occlusion of the major intracranial vessels at the base of the brain can be detected with MR angiography, but not as accurately as with cerebral angiography. Furthermore, for detection of more distal occlusions, cerebral angiography is still needed. A number of erroneous concepts about the risks and value of cerebral angiography have prevented its optimal use for patients with cerebrovascular disease. These myths can be countered by applying several rules to optimize the use of cerebral angiography. Subarachnoid hemorrhage is best evaluated with CT followed by detailed cerebral angiography, although MR angiography can be used as a screening test for aneurysms 3 mm or larger. Cerebral angiography is still necessary to confirm the diagnosis of cerebrovascular malformations, although MR angiography is a useful screening test. Cerebral angiography is required for the definitive diagnosis of arteritis, arterial dissection, or fibromuscular dysplasia.