Pulmonary venous abnormalities encountered on pre-radiofrequency ablation mapping multidetector computed tomography

Abstract

Multidetector computed tomography (MDCT) elegantly renders pulmonary venous anatomy. With increasing numbers of radiofrequency ablation procedures being performed, there is now a greater emphasis on pre-procedure imaging to delineate this anatomy. Pulmonary venous mapping studies can be performed with or without ECG-gating. However, ECG-gating improves both the quality of 3D images and the accuracy of pulmonary vein (PV) ostial diameter measurements. Including the superior thorax, and not just the left atrium and central PVs, allows visualization of aberrant pulmonary venous drainage to the brachiocephalic veins or superior vena cava. Normally, there are two superior PVs, one right and one left, and two inferior PVs, one right and one left. The right superior vein usually drains the right upper and middle lobe. The left superior vein drains the left upper lobe including the lingula. The inferior veins drain their respective lower lobe. PV anatomy is more variable than pulmonary arterial anatomy, and developmental anomalies are common. This article describes, illustrates and reviews the common anomalies of the PVs in our experience performing over 1000-pre-radiofrequency ablation cardiac MDCT studies. The commonest anomalies are supernumerary or accessory veins (on the right) and a (left) common trunk. More rarely, partial anomalous pulmonary venous return and Cor triatriatum are seen, and rarest of all is total anomalous pulmonary venous return, PV varix and single or multiple vein stenosis or atresia.