Colonic inflammation in pediatric inflammatory bowel disease: detection with magnetic resonance enterography

Background: Colonic involvement in pediatric inflammatory bowel disease is common. Magnetic resonance (MR) enterography is considered the best imaging modality for pediatric inflammatory bowel disease evaluation. It is unclear whether the lack of a dedicated large bowel preparation prevents a reliable colonic assessment. Objective: To determine the diagnostic performance of standard MR enterography in detecting and grading colonic inflammatory activity. Materials and methods: We retrospectively evaluated children who underwent both MR enterography and ileocolonoscopy with biopsies <4 weeks apart. Two radiologists independently reviewed MR examinations and quantified inflammation in each of the five colonic segments using a standardized MR score system. Findings were compared with histological examination of the corresponding segment. Mann-Whitney, Kruskal-Wallis, Jonckheere-Terpstra and Bland-Altman statistics were used. Results: One hundred seventy-five segments from 37 examinations were included. MR enterography diagnostic performance for inflammation was as follows: sensitivity 94% (95% confidence interval [CI]: 90-97%), specificity: 64% (95% CI: 57-71%). A significant positive correlation was found between MR score and inflammatory activity histologically graded (P<0.001, Jonckheere-Terpstra test). The interobserver agreement was good (mean difference between MR enterography scores was -0.03; limits of agreement -2.8 to 2.7). Conclusion: Standard MR enterography is sensitive for the detection of actively inflamed colonic segments. MR enterography might provide useful information for guiding biopsies and its role as an alternative to ileocolonoscopy in monitoring colonic disease activity in children should be further investigated.