Cerebral aneurysms are pathologic focal dilatations of the cerebrovasculature that are prone to rupture. These vascular abnormalities are classified by presumed pathogenesis. Saccular aneurysm is the most common form of aneurysm whereas Dolichoectatic, fusiform, or arteriosclerotic aneurysms are uncommon. Traumatic injury also may result in dissecting aneurysms in proximal vessels. The purpose of this study was to compare the accuracy of MRI with angiography technique in the identification of intracranial aneurysms. The intracranial vasculature was examined in 5 patients by MRA i The results of this study suggest that MRA can define the circle of Willis sufficiently to allow detection of intracranial aneurysms as small as 3-4 mm. MRA holds promise as a truly noninvasive screening examination of intracranial vasculature in patients at risk for aneurysms.
