SCANNING OF THE HEPATIC BLOOD POOL IN LIVER AMEBIASIS

Abstract
An amebic liver abscess consists of an area of necrosis caused by the implantation of trophozoites of the Entamoeba histolytica. This necrotic area is surrounded by hyperemic liver tissue, evident by celiac axis angiography as a hypervascular region. This process interferes with the normal phagocytic activity of the reticuloendothelial tissue around the abscess creating a bigger filling defect in the scans obtained with radiocolloids than the actual size of the lesion. Furthermore, when the abscess is located near the surface of the liver or in the left lobe, its boundaries are not precise in the scan image. A comparative study of liver scanning with colloidal In113m and scintigraphy of the hepatic blood pool with carrier-free, ionic In113m, was carried out in 125 patients with proven hepatic amebic abscesses. Carrier-free, ionic In113m proved to be more precise in the imaging of the actual size, shape, number and position of the abscesses, but was less efficient than colloidal In113m in depicting smaller lesions. It is concluded that liver scanning with colloidal In113m should be considered as the best routine procedure for the study and localization of amebic liver abscesses, but that in some special instances it should be complemented with a scintigraphic study of the distribution of the hepatic blood pool to gather more precise information about the actual size, shape, number and position of the abscesses.