Partial anomalous pulmonary venous return (PAPVR)

Imaging description In partial anomalous pulmonary venous return (PAPVR) there is an abnormal connection between the draining veins of one or more lobes to a systemic venous structure that drains into the right side of the heart, resulting in a left-to-right shunt. On CT the anomalous venous return is diagnosed based on recognizing the abnormal course of the intraparenchymal pulmonary vein. There are three common patterns of anomalous drainage: Anomalous right superior pulmonary venous drainage to the superior vena cava (SVC) – on CT the right upper lobe drains into the SVC, usually near the SVC/right atrial (RA) junction (Figure 53.1). Anomalous left superior pulmonary venous return to the left brachiocephalic (innominate) vein – on CT a vertical vein is seen coursing lateral to the aortic arch and aortopulmonary window. Blood flow is caudocranial (Figure 53.2). Anomalous right lower lobe drainage into the inferior vena cava (IVC), portal vein, or hepatic vein – on CT the right lower lobe vein courses inferomedially to connect with one of these structures (Figures 53.3 and 53.4).