CT slices (top) and view of volume rendered CT angiographies (bottom) are shown. (a1) and (a2) demonstrate a patent vein of Marshall (blue arrow and within the blue ring) passing between the left atrial appendage (LAA) and the left superior pulmonary vein (LSPV) before joining the coronary sinus (CS). (b1) and (b2) are partial anomalous pulmonary venous (green arrows) return draining part of the left upper lung into the superior vena cava (SVC). Note that the left superior pulmonary vein exists (within red circle) but appears diminutive compared to the other veins. (c1) and (c2) show partial anomalous pulmonary venous (red arrow) return draining part of the right upper lung into the SVC. In this case, the right superior pulmonary vein is absent (green circle). RIPV = right inferior pulmonary vein. (b2) and (c2) are flipped for better orientation.
