DIAGNOSIS OF UNRUPTURED ASYMPTOMATIC CEREBRAL ANEURYSMS BY MAGNETIC-RESONANCE ANGIOGRAPHY

The purpose of this study was to assess the incidence of unruptured as ymptomatic cerebral aneurysms detected by magnetic resonance angiograp hy (MRA). Three thousand patients without major neurological deficit h ad undergone MRA. MRA was obtained using three-dimensional time-of-fli ght method. Among the 3000 patients examined, 80 unruptured asymptomat ic aneurysms were discovered in 68 patients (2.3%). Twenty-six were lo cated on the internal carotid artery, 28 on the middle cerebral artery , 17 on the anterior communicating artery, 1 on the posterior cerebral artery and 8 on the vertebro-basilar artery. Thirty-seven patients un derwent surgery. Mortality was zero and morbidity was 5%. Three patien ts who declined surgery died of subarachnoid haemorrhage in the ensuin g 2.5 years.