Scintiangiographic Visualization of Systemic-Portal Venous Shunting as a Cause of 'hot Spot' in Superior Vena Cava Obstruction

A small number of pathologic entities such as Budd-Chiari Syndrome, cirrhosis, focal nodular hyperplasia, and superior and inferior vena cava obstruction has been reported to result in focal areas of increased uptake of radiocolloid on the hepatoscintigram. We recently studied a patient with focal accumulation of 99mTc-phytate at the inferior aspect of the liver, at the junction of the right and left lobe. The superior vena cava scintiangiogram was taken for the evaluation of the superior vena cava obstruction and collateral circulations. As a result of superior vena caval obstruction a considerable amount of blood flowed to the liver through the anterior parietal and periumblical venous channels. A certain fraction of radiocolloid delivered by the rete mirabile perfused to a localized area of the liver. This would explain the hot spot around the porta hepatis in this case.