title: Differentiation of focal intrahepatic lesions with 99mTc-red blood cell imaging.
abstract: The appearance of focal hepatic lesions on 99mTc-sulfur colloid images is nonspecific. As it is important to distinguish hemangiomas from other lesions prior to biopsy, a prospective study was performed using 99mTc-labeled red blood cells. Dynamic perfusion and delayed blood-pool images (1-2 hours) were obtained and lesion activity categorized as increased, equal, or decreased compared with the liver. Of 21 patients studied, 9 (43%) had one or more hepatic hemangiomas, and 8 of these 9 patients (89%) demonstrated increased blood-pool activity. The 12 nonhemangiomatous lesions consisted of 7 metastatic tumors, 2 hepatomas, 1 cirrhotic nodule, and 2 hepatic cysts. None of these 12 patients had increased activity on delayed blood-pool images. Early dynamic images of hepatic hemangiomas demonstrated variable activity (vascularity) and were not useful in differentiating hemangiomas from other lesions. Sensitivity was 89% and specificity 100%. Although liver enzymes are usually normal with hepatic hemangiomas, they may also be normal in metastatic disease. The authors recommend that delayed blood-pool imaging be performed prior to biopsy, particularly in patients without a known primary tumor or those with normal liver enzyme levels.
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging; D003560:Cysts / Q000000981:diagnostic imaging; D004912:Erythrocytes; D005260:Female; D006392:Hemangioma, Cavernous / Q000000981:diagnostic imaging*; D006801:Humans; D008102:Liver Circulation; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011877:Radionuclide Imaging; D013667:Technetium
chemical_list: D013667:Technetium