RADIOLOGY: VASCULAR: Case# 32987: DUPLICATED IVC. Young adult male involved in an MVA who presents for CT scan to rule out abdominal injury. Two large venous channels are seen on either side of the aorta below the level of the renal veins. Duplication of the IVC is an anomaly which occurs as a result of persistence of the left inferior vena cava during embryonic development. The left sided vena cava ascends to the level of the renal veins where it joins the right sided vena cava via vascular structures passing either anteriorly or posteriorly to the aorta. Either vena cava may predominate or they may be of equal size. CT images show a single right sided IVC at the level of the renal veins and above, two vascular structures crossing at the level of the renal veins and two vena cava on either side below the renal veins. Duplication of the IVC may be differentiated from a dilated left gonadal vein by following the structure more caudally. A duplicated vena cava ends at the level of the common iliacs, while a dilated left gonadal vein may be traced to the inguinal canal.