Focal Hepatic "Hot Spot" in Superior Vena Cava Obstruction

A focal area of increased activity (a hot spot) in the hepatic hilum on a radiocolloid liver scan has been well documented in patients with superior vena cava obstruction. Portal-systemic shunting that has developed between the superior vena cava and portal vein is thought to be the cause of this finding. Although this is well known, a direct correlation with other anatomic imaging methods has rarely been shown. The authors present a case of complete superior vena cava obstruction, in which Tc-99m stannous colloid hepatic SPECT could clearly locate a hot spot in the anterior part of the quadrate lobe, where contrast-enhanced radiographic CT also revealed an area of transient abnormal enhancement. In this case, an anatomic correlation between the radiocolloid hepatic hot spot and portal-systemic shunting on radiographic CT has been clearly demonstrated.