(A) Computed tomography image of the upper abdomen shows the liver, aorta, polysplenia, and absence of the inferior vena cava. (B) Abdominal venous return occurred via the collateral vein (hemiazygos vein draining into the superior vena cava). (C) Magnetic resonance image of the chest and abdomen shows the heart, liver, aorta, polysplenia, and absence of the inferior vena cava. (D) Abdominal venous return occurred via the dilated hemiazygos vein. Hypoplasia of the left kidney was noted.