Fig. 2

Thoracic and abdominal enhanced computed tomography demonstrating (a) A left IVC posterolateral to the abdominal aorta, converged by two renal veins (yellow arrow). b The left IVC gradually becomes thin, and continues with an enlarged hemiazygos vein (yellow arrow). Visceral position is normal. c The tiny azygos vein can be seen anterior to the vertebra, then crosses over the aorta and drains into the R-SVC (yellow arrow). The hemiazygos vein continues as the left superior intercostal vein via the accessory hemiazygos vein. The left superior intercostal vein eventually drained into the PLSVC at the level of the pulmonary artery bifurcation (red arrow). d In the left atrioventricular groove, a huge CS connected with the RA. e Reconstructive 3D imaging gives a better view of this anomaly. Ao: aorta; Az: azygos vein; CS: coronary sinus; HAV: hemiazygos vein; IVC: inferior vena cava; LV: left ventricle; PA: pulmonary artery; PLSVC: persistent left superior vena cava; RA: right atrium; R-SVC: right superior vena cava; RV: right ventricle