SCREENING FOR UNRUPTURED INTRACRANIAL ANEURYSMS WITH 3-DIMENSIONAL MAGNETIC-RESONANCE ANGIOGRAPHY

Unruptured asymptomatic intracranial aneurysms bleed at a rate of not less than 3% per year, with a mortality rate exceeding 50% per hemorrhage. Three-dimensional magnetic resonance angiography (3D-MRA) is able to depict the intracranial artery noninvasively and without using contrast media. The authors used 3D-MRA in 20 patients, (10 women, 10 men) with nausea, vomiting, and headache with hypertension to rule out intracranial aneurysm at same time brain computed tomography (CT) was performed. In this study, cases of subarachnoid hemorrhage (SAH) diagnosed by CT were excluded. Of 20 patients, only 1 was suspected to have intracranial aneurysm despite a normal-appearing CT, and this was confirmed by cerebral angiography. Two cases were suspected at the horizontal view of MRI; however, these were excluded by 3D-MRA. The authors began this study after finding the unruptured case, and are continuing it. The incidence thus is 5% so far. Discovering unruptured intracranial aneurysms is important for reducing the death rate from SAH, and 3D-MRA is useful for screening patients suspected of having aneurysm.