Differential includes hemangioma, hepatoma, and angiosarcomas. Findings are consistent with Hemangioma of the liver. Criteria for diagnosis of a hemiangioma on Technetium-99m labeled red blood cell (Tc99m-RBC) scan require the liver mass to have increase activity on 1 or 2 hour delayed imaging. Blood flow images usually show decrease uptake but can show early uptake. Large hemangiomas can show heterogeneous uptake.
Diagnosis of a hemiangioma on Tc-99m RBC scan has a very high positive predictive value (approaching 100%). Rare false positives have been reported for hepatomas and angiosarcomas. False negative studies are also rare and may be a result of fibrosis or thrombosis. Planar imaging can demonstrate hemangiomas from 3 cm and greater. Multiple headed SPECT can detect hemangiomas from 1.5 cm and greater.
Ref: Thrall, James, Nuclear Medicine: The Requisites, 1995, pp 204-210