Microbleeds in Moyamoya Disease: Susceptibility-Weighted Imaging Versus T2*-Weighted Imaging at 3 Tesla

OBJECTIVES: To prospectively evaluate differences in detectability of cerebral microbleeds (MBs) in Moyamoya disease (MMD) on susceptibility-weighted imaging (SWI) and T2*-weighted imaging (T2*WI) at 3 T. MATERIALS AND METHODS: SWI and T2*WI were applied for 50 consecutive MMD patients. MB was defined as a very low signal intensity area in each sequence without continuity from surrounding vessel structures. Numbers of MBs were compared between the 2 sequences. To assess visualization, a grading score was assigned to each MB from Grade 3 (prominent) to Grade 0 (normal-appearing) on SWI and T2*WI, respectively, and were compared by Wilcoxon signed rank test. RESULTS: A total of 37 MBs were detected in 21 patients (42%) on SWI, compared with 27 MBs in 16 patients (32%) on T2*WI, with significant difference in number of MBs between the 2 sequences (P = 0.002). Lesions displayed greater visual grading score on SWI than on T2*WI (P < 0.0001). CONCLUSIONS: SWI offers better detectability of MBs in MMD than T2*WI at 3 T.