Sonographic evaluation of abdominal and retroperitoneal lymph nodes in healthy subjects.

Purpose: Transabdominal ultrasonography is able to detect normal sized perihepatic lymph nodes. The role of transabdominal ultrasonography in detecting normal lymph nodes in other abdominal locations has not yet been examined. Methods: 92 healthy volunteers (57 male, 35 female; age: 33 +/- 9 [19 - 66] years) were examined by transabdominal ultrasonography. The peripancreatic region, the location between the inferior vena cava and aorta, left paraaortal region, and the right mesenteric region next to the terminal ileum were studied with high resolution ultrasound. All transabdominal ultrasound examinations were performed with a 3.5 and 5 MHz probe using a special magnification mode without substantial loss of resolution (RES(R)-mode, Acuson) and additionally by colour doppler imaging (Acuson XP). Results: In 80/92 (87%) of the healthy subjects, all regions could be adequately visualized. In 72% of patients with adequate visualization, abdominal lymph nodes were detectable. Abdominal lymph nodes could be sonographically detected peripancreatically in 14/80 (18%), in the location between the inferior vena cava and aorta in 44/80 (55%), in the left paraaortal region in 32/80 (40%), and in the right mesenteric region next to the terminal ileum in 31/80 (39%) of the healthy subjects. Conclusion: High resolution ultrasonography is able to detect normal lymph nodes in different abdominal locations in 72% of healthy subjects. Sonographic detection of singular normal-sized abdominal lymph nodes is not indicative of abdominal disease.