Role of Tc-99m labeled RBC SPECT in haemangioma of the liver

Full text: Haemangioma of the liver must be included in the differential diagnosis of all focal hepatic lesions. Nuclear medicine imaging techniques continue to play a unique role in the evaluation of hepatic masses. Role of planar scintigraphy in the diagnosis of hepatic haemangioma is already established although it has limitations, which can be significantly improved by means of SPECT studies. A prospective study was carried out to evaluate Tc-99m red blood cell SPECT imaging in liver haemangioma and compare it with CT findings. Radionuclide liver scan, both planar and SPECT was done in 10 patients who had 16 liver masses diagnosed as haemangiomas on their CT. The acquisition protocol was an immediate perfusion phase study in an anterior view followed by SPECT of the liver at 2 hours. A perfusion/blood-pool mismatch is the hallmark finding for hepatic haemangioma. The smallest haemangioma detected with isotope scan was of 1.55 cm size. Planar scintigraphy showed a sensitivity of 82% versus 94.2% for SPECT. It was mostly due to missing of lesions less than 2 cm in size on planar scans. For cavernous haemangioma (n=4) the specificity and positive predictive value was 100%. We believe that hepatic scintigraphy still continues to play an important role in the diagnosis of hepatic masses especially for liver haemangioma where Tc-99m labeled red blood cell scanning has considerably high specificity. However, planar imaging has poor sensitivity especially for the identification of smaller lesions. Hepatic scintigraphy is non-invasive, easy to perform and inexpensive. In our opinion, when a suspicion of hepatic haemangioma is raised on CT or other imaging modalities, it needs to be confirmed by radionuclide blood-pool study. (author)