To what extent can diverse types of liver lesions mimic hemangiomas? A retrospective quantitative analysis of masses found to be positive in SPECT/CT with labeled blood cells - a preliminary report

• Published in: Polish journal of radiology Vol. 78; no. 4; pp. 21 - 26
• Main Authors: Swiętaszczyk, Cyprian, Pilecki, Stanisław E
• Format: Journal Article
• Language: English
• Published: Poland 01-01-2013
• Subjects: Tc-99m; liver hemangioma; quantitative analysis; labeled red blood cells; SPECT/CT
• ISSN: 1733-134X
• DOI: 10.12659/PJR.889225

Although specificity of SPECT/CT examination using technetium-99m radiolabeled red blood cells (Tc-99m-RBC) for detection of liver hemangiomas is very high, it is still not perfect. It is possible to overlook a malignancy. Moreover, the difference in accumulation of RBCs between a hemangioma and uninvolved liver remains unknown. The aim of the study is to determine the quotients of accumulation of Tc-99m-RBC in hemangiomas and in normal liver parenchyma (HEM/liv), and to verify, whether the quotient could be potentially helpful in distinguishing hemangiomas from other RBC-accumulating liver masses.
34 liver lesions larger than 1.5 cm classified scintigraphically (qualitatively) in our Department as either typical or suspicious of hemangioma 1.5-4 years earlier were enrolled in this retrospective study. Their SPECT/CT images were acquired 1 hour after in vivo labeling of RBCs with Tc-99m. In reconstructed images, ellipsoidal regions of interest (ROIs) with diameters of about 1.5 cm were created in the assessed lesions (HEM) and in the uninvolved liver parenchyma (liv). The HEM/liv quotients were calculated for each mass. The results were compared with radiological data.
31 lesions were found to be clinically and radiologically typical for hemangiomas, their HEM/liv ratios were at least 1.6 (smaller masses) or 1.8 (larger masses). One lesion with HEM/liv ratio equal to 1.21 was classified as metastasis. Two lesions with HEM/liv 1.42 and 1.46 were classified as benign foci other than hemangioma.
The quantitative analysis can be preliminarily proposed as a helpful tool in the assessment of possible liver hemangiomas.