[Sonography of the superior mesenteric artery. Normal anatomy variations and value for the analysis of retroperitoneal space occupying processes].

The superior mesenteric artery (SMA) can be demonstrated by ultrasonography under adequate conditions as a tubular liquid structure of 3 to 7 mms. in diameter, which parallels the abdominal aorta at a distance of 2 to 5 mms. The aortomesenteric distance is higher in patients with arteriosclerosis or aneurysm of the abdominal aorta, enlarged pre-aortic lymph nodes or other retroperitoneal masses. Its measurement can be recommended for quantitative assessment of retroperitoneal lymphadenopathy. Anatomic variations and postoperative changes may alter the course of the SMA. Measurement of the aortomesenteric angle is of no practical value.