Cavernous malformation, with an associated developmental venous anomaly

On CT, a small, well delineated, hyperdense, round, focal lesion is seen pre-contrast, to the right and posterior to the fourth ventricle. On axial T2-weighted scans, a complete hemosiderin rim is demonstrated, together a “popcorn ball” appearance centrally, with mixed high and low signal intensity – all characteristic for a cavernous malformation. Just lateral and posterior to the lesion is an additional finding, a large flow void and associated caput medusa, consistent with an associated developmental venous anomaly.

Cavernous malformation, with an associated developmental venous anomaly

Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015)