99mTc-RBC liver Scintigraphy: Planar vs. SPECT in liver hemangioma

Introduction: Hepatic cavernous hemangioma (HCH) is the most frequent benign liver lesion, with an incidence of 5-7%. Tc99m-RBC scintigraphy has highest specificity for diagnosis of HCH. However, It has some limitations in small sized lesions due to low resolution of gamma cameras. The purpose of this study was to determine the value and diagnostic accuracy of Tc-99m RBC scintigraphy on SPECT mode in comparison to planar images. Methods:Planar and SPECT images of 49 patients referred to Department of Nuclear Medicine for Tc999m-RBC scintigraphy were interpreted by two nuclear medicine specialists. All patients were followed up to 2 years. Results: From 69 HCHs, 37( 53.6%) and 61(88.4%) of masses showed increased tracer activity respectively. Mean size of HCHs with increased tracer activity in SPECT, planar, anterior and posterior planar images was 13.37, 23.09, 25.41 and 27.35 mm respectively.Smallest and greatest HCHs were 6 and 189 mm in size, while the smallest HCH that distinguished in SPECT and planar images were 13 and 17.3 mm in size. The sensitivity of planar and SPECT for diagnosis of HCH>10 mm was 56.3% and 93.8% respectively. For HCH>15 mm, these were 61% and 96.6% respectively. Left lobe HCH was better seen on planar images specially on the anterior views. So we need SPECT more frequently in the HCH of the right liver lobes. Conclusion:The prevalence of HCH in females is more than the males. The sensitivity of the Tc99m-RBC SPECT is more than the Planar images. This difference specially is more prominent in the HCH with 10 to 20 mm in size. We can distinguish HCH>30 mm with planar images, while the sensitivity of the SPECT for 10 to 20 mm HCHs was 80%.