Azygos Continuation of the Inferior Vena Cava

  • Etiology: post-hepatic segment of inferior vena cava is present draining only hepatic veins into right atrium, there is an interruption of infrahepatic/suprarenal inferior vena cava, renal segment of inferior vena cava drains via azygos vein into superior vena cava
  • Imaging: absence of the hepatic segment of the inferior vena cava with azygos continuation

Cases of Azygos Continuation of the Inferior Vena Cava

CT of azygos continuation of the inferior vena cava
Coronal CT with contrast of the abdomen (below) shows interruption of the infrahepatic inferior vena cava which then communicates with the hemiazygos vein to the left of the spine which then via dilated azygos and hemiazygos venous collaterals alongside the vertebral body on the axial CT (above) ultimately drain into the superior vena cava.