Cerebral microhemorrhage

Cerebral microhemorrhages, or cerebral microbleeds, are small focal intracerebral hemorrhages, often only visible on susceptibility-sensitive MRI sequences.

Pathology

Common etiologies
Less common etiologies

Radiographic features

Cerebral microhemorrhages are generally only seen on MRI and are best seen on susceptibility weighted T2* sequences such as gradient-recalled echo (GRE) and susceptibility weighted imaging (SWI).

They appear as conspicuous 2-10 millimeter punctate regions of signal drop out with blooming artifact. This blooming grossly overestimates the size of the lesions, and they are usually inapparent on other sequences.

Differential diagnosis

  • artificial heart valve metallic emboli (very rare)
  • pneumocephalus (very rare without proceeding surgery)
  • flow voids of veins
  • intracranial calcification