Detection and risk stratification of cerebral microbleeds by susceptibility weighted imaging

Background and Purpose: Cerebral microbleeds have important clinical implications in Stroke and dementia. We investigated the role of SWI in detection and risk stratification of chronic microbleeds. Materials and Methods: Hospital based , prospective, case-control study was performed in Department of Radiodiagnosis and Imaging , ASCOMS , Jammu using 1.5 Tesla Siemens Magnetom Essenza. Our study comprised of 30 subjects ( n = 30, M = 21, F=9, mean age 68 y) with an equal number of age and sex matched controls. Cases were divided on basis of number (> or < 5) and size (> or < 5mm) of microbleeds on reverse phase SWI and T2*GRE imaging. Results: The distinct advantage of SWI sequence was noted in detecting and evaluating CMBs compared to the T2*GRE sequence which demonstrated only 70.5% of the microbleeds seen on SWI. Most patients in the present study exhibited multiple CMBs, which were noted simultaneously in various parts of the brain. A substantially higher number of patients had mixed CMBs (n=21, 70%) than in isolated deep or lobar locations. Majority of the subjects (n=21; 70%) had more than 5 CMBs.Larger sized CMBs i.e. CMBs ≥5mm had a strong correlation with both hypertension and diabetes as compared to CMBs < 5mm. There was a higher frequency of patients with lobar CMBs (n=27, 90%) followed by the deep location (n=21, 70.%). In deep grey nuclei, majority of CMBs were seen in thalamic region (n=234; Mean ± SD = 3.49 ± 6.18) and in infratentorial location, more CMBs were seen in cerebellum (n=192; Mean ± SD = 2.87 ± 6.18). Hypertension and diabetes had a moderate correlation with CMBs in the deep grey nuclei location as well as infratentorial location. Conclusion: Due to increased detection of microbleeds we strongly recommend use of SWI as sequence of choice in microbleed detection. SWI offered greater reliability and sensitivity for CMB detection as compared to the T2*GRE sequence and is presently the gold standard modality for quantifying CMBs. CMBs may further indicate inappropriately treated hypertension and diabetes.