Termination of the vertebral veins: Evaluation by multidetector row computed tomography.

The purpose of this study was to evaluate the topographic anatomy of the vertebral vein (VV) in the lower neck and thoracic inlet using CT scans. Enhanced CT scans using 32-MDCT were obtained for 199 consecutive patients. Reconstructed images with 1-mm section thickness/intervals were evaluated by two radiologists examining the drainage point, number, and route of VVs using frame forwarding and the rewind function on the DICOM viewer. The VV was classified into four types as follows: Type A (80.6%), a VV that descended ventral to the subclavian artery (SA) and drained into the upper portion of the brachiocephalic vein (BCV); Type B (5.8%), a VV that descended dorsal to the SA and drained into the upper portion or the lower portion of the BCV; Type C (8.3%), a doubled VVs that crossed both sides of the SA and drained into the upper portion of the BCV and formed a common trunk; Type D (5.3%), a VV ventral to the SA that drained into the upper portion of the BCV and another VV dorsal to the SA drained into the upper portion or the lower portion of the BCV. Some variations were observed in regard to the drainage point, number, and route of the VVs. Classification of the VV may be useful for interpreting chest CT scans and in better understanding the embryologic development of the vertebral vein.