Case 292: Hemangioma
30 year old man with Hepatitis B.
MR: Cavernous, bright dot sign
MR shows small cavernous hemangioma in segment 4A.
Unenhanced T1w image shows a hypointense focal lesion. T2w images with fat saturation show high signal intensity ("light bulb sign"). Arterial contrast sequence with with Gd-EOB-DTPA shows a solitary eccentric focus of enhancement ("bright dot sign"), and discontinuous nodular peripheral enhancement on portal contrast phases. Hepatobiliary contrast phase after 20 minutes shows lesion is hypointense to liver parenchyma and isointense to blood pool.
The bright dot sign is considered very specific for cavernous hemangioma and is particularly helpful in the analysis of lesions investigated with hepatobiliary agents, where the delayed centripetal enhancement is not appreciated due to the surrounding dominant hepatocellular signal of the liver parenchyma.
Note smaller cavernous hemangioma posterior to the IVC.