On an axial CT of the abdomen at the level of the second lumbar vertebra, which structure is seen immediately anterior to the abdominal aorta?

• A Left renal vein
• B Right renal vein
• C Inferior vena cava
• D Superior mesenteric artery ✓

Explanation

The superior mesenteric artery (SMA) arises from the front of the abdominal aorta at the level of L1, just below the coeliac axis, and is visible on axial CT anterior to the aorta at the L1–L2 level surrounded by fat and the superior mesenteric plexus. The left renal vein crosses anterior to the aorta (and posterior to the SMA) slightly lower. The IVC lies to the right of the aorta. Confusion arises because the left renal vein is just posterior to the SMA; at this level the SMA is the most prominent anterior aortic relation.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.