Diagnosing proximal small bowel involvement in Crohn′s disease (CD) can be challenging with magnetic resonance enterography (MRE). CD can be associated with the inflammatory process like peri-intestinal inflammatory reactions, including the presence of inflamed mesenteric lymph nodes.

A recent study evaluated the significance of inflamed mesenteric lymph nodes adjacent to the jejunum at MRE in CD and how they relate to proximal bowel disease as detected through video capsule endoscopy (VCE). It included 64 patients with CD who underwent MRE and VCE within one year.

The study collected data for examinations performed between August 2013 and February 2021. Radiologists, blinded to the clinical data, independently reviewed the MRE images. The study examined the association between the appearance of mesenteric lymph nodes adjacent to the jejunum at MRE and disease activity according to VCE Lewis scores of the proximal small bowel.

• VCE detected the proximal disease in 37.5% of the patients. 
• The presence of regional lymph nodes in the jejunal mesentery showed significant association with the jejunal disease, as seen on VCE. 
• Of the 20 patients having proximal mesenteric lymph nodes at MRE, 75% displayed jejunal disease at VCE. 
• The number of regional lymph nodes showed a positive correlation with jejunal disease. 
• Other MRE features of lymph nodes did not significantly predict jejunal CD.

Thus, in patients with CD, inflamed regional lymph nodes in the jejunal mesentery at MRE may suggest proximal small bowel disease, even when bowel wall features at imaging do not indicate disease involvement.

Maconi G, Sorin V, Kopylov U, et al. Diagnostic significance of mesenteric lymph node involvement in proximal small bowel Crohn′s disease. Therapeutic Advances in Gastroenterology. 2022;15. doi:10.1177/17562848221118664