MR-ANGIOGRAPHY OF RUPTURED ANEURYSMS IN ACUTE SUBARACHNOID HEMORRHAGE

PURPOSE: To determine the efficacy of high-resolution MR angiography f or the prospective diagnosis of ruptured aneurysms in acute subarachno id hemorrhage, METHODS: We used 3-D time-of-flight MR angiography with a large image matrix (193 x 512 frequency-encoding steps), magnetizat ion transfer saturation, and a variable flip-angle excitation (tilted optimized nonsaturating excitation [TONE]) to study 28 patients with a cute subarachnoid hemorrhage, The MR angiograms were compared with int raarterial digital subtraction angiographic (IA-DSA) images. RESULTS: Thirty-five (90%) of 39 aneurysms were detected prospectively with MR angiography. At least one aneurysm was identified with MR angiography in 25 (96%) of 26 patients with aneurysms proved by IA-DSA. Although f our aneurysms were missed prospectively, three of these were detected retrospectively with MR angiography. Six aneurysms (18%) of those evid ent on MR angiograms were 3 mm or less in diameter, In one patient, ad ditional targeted maximum intensity projections were greatly helpful f or the ensuing IA-DSA by determining the optimizal projection angle by which to depict a ruptured aneurysm that neither routine MR angiograp hy nor routine IA-DSA detected, CONCLUSION: High-resolution MR angiogr aphy may be a useful diagnostic technique for detecting ruptured aneur ysms, even in patients with acute subarachnoid hemorrhage, Initial MR angiography offers valuable and reliable information on ruptured aneur ysms in acute subarachnoid hemorrhage, allowing the optimization of pr ojection angles at conventional angiography.