Sonographic demonstration of the right ascending lumbar vein

The right ascending lumbar vein has not previously been described in the sonographic literature. This vein is an important part of the abdominal prevertebral anastomotic network and appears sonographically as an anechoic tubular structure lying dorsal and parallel to the inferior vena cava. It was detected in 14 of 20 randomly selected patients who underwent routine abdominal sonography and had a mean diameter of 2.0 mm +/- 0.8 SD. In another six patients with abnormal blood flow in the inferior vena cava, dilated lumbar veins were demonstrated.