Figure 4b. Hypogenetic lung syndrome in a 22-year-old asymptomatic woman. (a) Axial CT angiogram obtained at the level of the lung bases shows a large anomalous vein (*) that drains into a dilated inferior vena cava (IVC). (b) Volume-rendered reformatted image demonstrates that the anomalous vein (*) drains into the IVC below the level of the right hemidiaphragm. L = liver. (c) Anteroposterior venous phase pulmonary angiogram obtained for shunt quantification helps confirm the presence of an anomalous pulmonary vein. (d) On a minimum-intensity-projection reformatted image, the right upper lobe bronchus is not seen, allowing visualization of the associated hypogenetic lung and central bronchi.