Three-dimensional reconstruction of a spiral CT angiogram through the left upper extremity (oriented in a cranial–caudal projection with the spine at the top of the image and the manubrium at the bottom) reveals obstruction of the superior vena cava (arrow) with venous collaterals around the left shoulder (arrowheads). The enlarged azygous vein is located posteriorly along the right side of the spine adjacent to the obstructed portion of the superior vena cava.
CT angiogram of the deep venous system of the left upper extremity. The image is oriented in the anteroposterior projection with mild caudal rotation. There is marked irregular narrowing of the left subclavian vein (arrow) with numerous venous collaterals around the left shoulder and to the vertebral plexus (arrowheads).