Anatomy of the Origin of the Gonadal Veins on CT

Purpose: To study gonadal vein (GV) anatomy on multidetector computed tomography (CT) and define guidelines to aid their identification. Materials and Methods: A total of 106 multidetector CT examinations obtained for abdominal pain were reviewed by three independent readers. The location and three-dimensional orientation of the GV ostia were investigated. Six studies were excluded because the GVs were incompletely visualized. Results: The anatomy of the right and left GVs was defined in 100 and 99 cases, respectively. On the left side, 97 of 99 inserted directly into the inferior wall of the left renal vein (> 85% within 45 mm of the edge of the inferior vena caya [IVC] or within 10 mm of the edge of the spine). Two patients showed variant caval anatomy, and the GV directly joined the variant IVC. On the right side, 92 of 100 inserted directly into the IVC (> 83% within 25 mm below the renal vein ostium). The right GV ostium was anterolaterally located (ie, between 270 degrees and 360 degrees) in the majority of cases. Eight right GVs joined the right renal vein within 2 cm of the renal vein ostium. Conclusions: When searching for the right GV, the right anterolateral quadrant should be searched first, as much as 25 mm caudal to the right renal vein ostium. If unsuccessful, the inferior wall of the right renal vein within 2 cm of its origin should be interrogated. On the left side, the inferior wall of the left renal vein should be examined. If a left-sided IVC is found, the GV will join it directly.