Fig 3. Venous phase of the 3D contrast-enhanced MR angiographic study, on a coronal MIP (maximum intensity projection) images.

A, Enlarged vertebral venous plexus (VVPx) consisting of epidural and paravertebral veins (arrows) extending up to the renal hilus level and consequently draining into the azygos-hemiazygous veins (open arrow).

B, Infrahepatic inferior vena cava cannot be distinguished as a separate structure. Common iliac veins appear at the conjunction level just behind the common iliac arteries (arrows) and drain into the VVPx eventually (not shown here). Enlarged left ovarian vein and a large-caliber tortuous right renal vein as a secondary drainage pathway of the lower body segments, as well as the VVPx, can also be recognized (asterisk). Arrowheads indicate the enlarged azygous vein.