MAGNETIC-RESONANCE ANGIOGRAPHY IN INTRACR ANIAL ANEURYSMS AFTER SUBARACHNOID HEMORRHAGE

Magnetic resonance angiography is now commercially available for a var iety of scanners and is being increasingly applied in the diagnosis of cerebrovascular disorders. Considering the clinical consequences, esp ecially in intracranial aneurysms, studies to determine the sensitivit y and specificity of the method are essential. Here we report our expe rience with a 3D-FISH time-of-flight magnetic resonance angiography pr otocol in 52 patients who have suffered an acute subarachnoid hemorrha ge. In 26 of the 52 patients, conventional angiography identified 31 a neurysms (3-20 mm) that were confirmed during surgery or autopsy. Magn etic resonance angiography correctly identified 28 of the 31 aneurysms (sensitivity 90.3 %) and missed one ruptured (3 mm) and two incidenta l aneurysms (3 mm) in patients with multiple aneurysms. The sensitivit y for a ruptured aneurysm was 96 %. The 26 patients who suffered subar achnoid hemorrhage without evidence of an intracranial aneurysm on rep eated angiography served as a control group. Magnetic resonance angiog raphy revealed no false-positive findings, resulting in a specificity of 100 %. In correlation with the literature, we conclude that magneti c resonance angiography is not sensitive enough for the management of acute sub arachnoid hemorrhage. However, the method provides important complementary information for definition of the bleeding site in pati ents with multiple aneurysms. In addition, the calculation of projecti ons not possible with conventional angiography can aid surgical planni ng. Since only very small aneurysms were missed by magnetic resonance angiography, the sensitivity seems appropriate to screen asymptomatic patients who are at risk for intracranial aneurysms,