Not all cortical cerebral microbleeds are due to cerebral amyloid angiopathy.

Abstract

Cerebral microbleeds (CMBs) are commonly detected on routine MRIs of the brain in centres that incorporate a susceptibility sequence as standard. The susceptibility weighted imaging (SWI) sequence is increasingly available and is more sensitive than gradient echo in detection of small susceptibility abnormalities caused by iron from haemoglobin, occurring either as CMBs or cortical superficial siderosis, with the underlying diagnosis usually inferred to be cerebral amyloid angiopathy (CAA) for the more peripheral hemisphere location of CMBs. Cortical superficial siderosis is likely a more specific marker of CAA1 and in patients with cortico-subcortical CMBs alone, other causes should be considered.