This axial T1-weighted gadolinium-enhanced MRI shows a “caput medusa” sign in the cerebellar midline (click image for arrows), characteristic of a developmental venous anomaly. There was a large draining vein to the vein of Galen (not shown).
DVA, otherwise known as venous angioma, is a vascular malformation due to persistence of embryonic veins. It is the most common cerebral vascular malformation. DVA are usually asymptomatic. They may be associated with cavernous haemangioma, in which case there is a risk of haemorrhage, or cortical dysplasia, with a risk of seizures. No treatment is required for solitary, uncomplicated DVA.
Reference: Osborn A, et al. Diagnostic Imaging: Brain Amirsys 2004
Credit: Dr Laughlin Dawes