Venous angioma

-Is a normal variant.

-Clinically silent.

-A tuft of abnormally enlarged medullary veins draining into a central venous trunk.

After contrast administration, the MRI findings are highly characteristic of a venous angioma (contiguous axial images shown). Several small radially oriented (medullary) vessels connect to a larger vessel ("caput medusa," "spoke-wheel," or "umbrella" pattern). Because of slow flow, enhancement of the venous channels occurs (arrows). Supratentorial venous angiomas most commonly show enhancement extending to the ventricular ependyma (left image, curved arrow). The adjacent parenchyma is typically nonenhancing, unless there is venous stasis due to flow obstruction within the venous angioma.