The hepatic venogram at the left reveals lack of filling in the venous outflow due to hepatic venous thrombosis with Budd-Chiari syndrome. In the venogram at the right, there is a central dark area from thrombosis in the inferior vena cava that extended from the hepatic veins. The Budd-Chiari syndrome can result from polycythemia vera, pregnancy, and carcinomas in the abdominal region.