Detection of intracranial aneurysms by three-dimensional time-of-flight magnetic resonance angiography.

The purpose of this study was to investigate the reliability of magnetic resonance angiography (MRA) for detection of intracranial aneurysms. Ninety-six consecutive patients who underwent both MRA using the three-dimensional time-of-flight technique (3D TOF) with the rephase/dephase subtraction method and conventional angiography were reviewed. MRA showed 22 aneurysms in 19 patients, and conventional angiography 28 aneurysms in 23 patients. The sensitivity of MRA was thus 79% for aneurysms in 83% of patients. MRA showed no aneurysm in 67 of 73 patients without aneurysms; its specificity was therefore 92%. The 6 false positive interpretations were suspected internal carotid artery aneurysms.