Case report: diagnosis of cavo-portal shunt in inferior vena cava obstruction: comparison between venography and dynamic scintigraphy.

A cavo-portal shunt is a rare complication of inferior vena cava obstruction. A patient is described who had complete obstruction of the inferior vena cava (IVC) due to extension of tumour thrombus from a left renal cell carcinoma. Venocavography clearly showed many collateral veins but not a cavo-portal shunt. Dynamic scintigraphy, however, distinctively showed a draining vein and subsequent homogeneous radionuclide uptake of the liver, which indicates a cavo-portal shunt.