Reflections on the etiology of hot spots on liver scans

Abstract

Liver scintigraphy demonstrated areas of increased radiocolloid uptake in three cases with obstruction of the superior vena cava and extensive collateral circulation through the veins of the thoracic wall. The pattern of the hyperactive zones is indicative of predominant vascularization of the liver via the umbilical vein, with high colloid particle deposition in the quadrate lobe and adjacent part of the right lobe. These liver regions vascularized by the first intrahepatic branches of the umbilical vein as demonstrated by postmortem angiography, probably extract a great portion of the tracer dose, resulting in localized hyperactivity. An identical liver scan image was, however, found in a fourth case without evident superior vena cava syndrome. In this patient, presenting with a bronchus carcinoma with paratracheal metastatic lymph nodes, there is no explanation metastatic lymph nodes, there is no explanation (collateral circulation without vena cava obstruction?) for the abnormal tracer distribution within the liver.

Inferior vena cava thrombosis with hot quadrate lobe sign demonstrated by Tc-99m macroaggregated albumin radionuclide venogram and single-photon emission computed tomography/computed tomography

“…Several causes of focal hepatic hotspots on nuclear medicine imaging have been described. Obstruction of either superior vena cava or IVC has been reported to result in hotspot in the quadrate lobe caused by collateral venous drainage through the umbilical or paraumbilical veins which in turn drain into the left branch of the portal vein resulting in “systemic-portal shunting,”[ 13 14 15 ] while hepatic vein obstruction in Budd-Chiari syndrome is related with focal uptake in the caudate lobe. [ 16 ] Hepatic pathology including focal nodular hyperplasia,[ 17 ] regenerative nodules,[ 18 ] liver abscess, hemangioma, and hepatocellular carcinoma[ 19 ] have also been reported to accumulate radiocolloids, but can occur anywhere in the liver.…”