High Prevalence of MRI Features of Mesenteric Panniculitis in Chronic Intestinal Inflammation: A Retrospective 3-T MRI Study

Background/Objectives: Mesenteric panniculitis (MP) is a chronic inflammatory and sclerosing disorder of the mesenteric fat. This study evaluated the occurrence and MRI appearance of MP in patients with chronic inflammatory bowel disease and chronic inflammatory bowel conditions. Methods: In this retrospective single-center study, 312 individuals underwent standardized 3-T MRI Sellink examinations, including 252 patients with clinically confirmed chronic inflammatory bowel disease or chronic inflammatory bowel conditions and 60 control patients without intestinal inflammation. MP was diagnosed when at least three of five characteristic MRI findings were present: increased mesenteric signal intensity on fat-saturated fluid-sensitive T2 sequences, fat ring sign, pseudocapsule, embedded micronodules, and displacement of bowel loops. Group differences were analyzed using contingency table analysis with Monte Carlo exact testing; Pearson’s chi-square test and Holm-adjusted pairwise post hoc comparisons were additionally performed. A p-value < 0.05 was considered statistically significant. Results: MRI signs of MP were present in 221/312 patients (70.8%) overall, including 220/252 patients (87.3%) in the disease cohort and 1/60 patients (1.7%) in the control group. Among patients with MP, the underlying diseases/conditions were Crohn’s disease (104/220, 47.3%), sigmoid diverticulitis (88/220, 40.0%), and ulcerative colitis (28/220, 12.7%). The overall distribution of MP extent differed significantly among diagnostic groups (Monte Carlo exact test: p = 0.030), although adjusted pairwise comparisons were not statistically significant. Topographically, MP showed a clear predominance in the left upper quadrant. Conclusions: MRI-defined features consistent with mesenteric panniculitis are highly prevalent in this selected cohort of patients with chronic intestinal inflammatory conditions when standardized criteria are applied. These findings suggest that MP-like mesenteric changes may represent a common imaging correlate of chronic intestinal inflammation rather than a rare incidental finding. MRI enables consistent detection and topographic assessment of MP.