cerebral microbleed
Small hemorrhagic lesions visible on susceptibility-sensitive MRI sequences, indicating underlying vasculopathy.
Full Definition
Cerebral microbleeds are small (2-10 mm), round, hypointense lesions seen on T2*-weighted gradient echo or susceptibility-weighted imaging sequences, representing microscopic hemorrhages caused by small vessel disease. These lesions indicate blood-brain barrier dysfunction and are associated with increased risk of future hemorrhagic and ischemic strokes. The distribution pattern of microbleeds can help differentiate between cerebral amyloid angiopathy (lobar distribution) and hypertensive vasculopathy (deep/infratentorial distribution). Microbleed burden is an important consideration in anticoagulation decisions.
Usage
Usage note: Best visualized on susceptibility-sensitive sequences like SWI or GRE.
In Context
- "Multiple lobar cerebral microbleeds were suggestive of underlying cerebral amyloid angiopathy." — elderly patient bleeding risk assessment
- "The presence of numerous cerebral microbleeds influenced the decision regarding anticoagulation therapy." — atrial fibrillation management