Cerebral microbleeds: Histopathological correlation of neuroimaging

Background: In recent years, there has been a growing interest in cerebral microbleeds (CMBs) and their role in cerebrovascular disease. A few studies have investigated the histopathological correlation between CMBs and neuroimaging findings. We conducted a systematic review in an attempt to characterize the pathological and radiological correlation. Methods: A systematic literature search was conducted for studies in which CMBs were characterized histopathologically and correlated with MRI findings. Results: Five studies met the inclusion criteria, with a total of 18 patients. Hemosiderin deposition was reported in 42 CMBs (49%), while 16 CMBs (19%) were described as old hematomas which stained for iron, 13 (15%) had no associated specific pathology, 11 (13%) contained intact erythrocytes, 1 (1%) was due to vascular pseudocalcification, 1 (1%) was a microaneurysm and 1 (1%) was a distended dissected vessel. Lipofibrohyalinosis was the most prominent associated vascular finding. Amyloid angiopathy was present primarily in patients with dementia. Conclusions: Although histopathological associations have been observed using MRI in patients with CMBs, the findings have yet to be validated and further research is warranted. Copyright © 2011 S. Karger AG, Basel.