Systemic to pulmonary venous communication (right-to-left shunt) in superior vena cava obstruction demonstrated by spiral CT.

An unusual case of systemic vein to pulmonary vein communication in superior vena cava obstruction is reported. This was a right-to-left shunt, demonstrated by spiral CT and aided by three-dimensional reconstruction. The pulmonary venous shunts were mainly seen in fibro-atelectatic lung where prominent bridging veins were concentrated.