HIDA and pseudosplenomegaly in hydatid cyst and amebic abscess of liver.

Tc-99m-HIDA and related compounds have been universally accepted for studying the hepatobiliary system. The authors describe yet another use of HIDA documented by three case reports. HIDA is taken up by the hepatocytes and not by the reticuloenthothelial system. Two patients are described, one with hydatid cyst and the second with amebic abscess of the liver, in whom splenomegaly was diagnosed clinically and confirmed by ultrasonography as well as by Tc-99m-tin colloid scan. HIDA imaging proved the spleens to be normal. A displaced right lobe of the liver in one case, and an enlarged left lobe in the other, led to this erroneous diagnosis, which the authors term "pseudosplenomegaly." In the third patient, HIDA not only clarified the extent of the spleen, but also revealed a "cold" area in the left lobe of the liver. This was missed by the colloid scan because of the position of the "cold" area.