Diagnosis of hepatic hemangiomas with 99mTc-labeled red blood cell scanning: value of SPECT.

99mTc-labeled red blood cell (RBC) scanning is considered a highly specific technique for the study of hepatic hemangiomas. However, planar imaging displays poor sensitivity for the identification of small lesions. The authors consider a survey group of 119 patients, of whom 66 with a presumed diagnosis of hepatic hemangioma, for a total of 77 lesions ranging from 0.8 to 15 cm in diameter. The study was conducted with three-phase planar imaging and single photon emission computed tomography (SPECT). The results, which confirm a high specificity of 99mTc-RBC scanning (100%) in the study of hepatic hemangiomas, show that SPECT significantly improves the detection of these lesions (71%) compared to the delayed static study (52%), with the largest gain for lesions between 2-3.5 cm (83% versus 51%). However, also SPECT has difficulty in detecting lesions of less than 2 cm. With regard to three-phase imaging, the authors point out that the pattern considered characteristic for hepatic hemangiomas (perfusion blood-pool mismatch) is infrequent (13%).