Bowel magnetic resonance imaging of pediatric patients with oral mannitol - MRI compared to endoscopy and intestinal ultrasound

The purpose of this study was to assess the sensitivity, specificity, and diagnostic accuracy of magnetic resonance imaging (MRI) in pediatric patients with clinical suspicion of inflammatory bowel disease (IBD) by comparing MRI and ultrasound (US) to endoscopy, the gold standard. A median volume of 300 ml of mannitol in a 4.5% watery solution were ingested by 43 children prior to examination. The 53 MRI examinations were compared with 20 endoscopies and 41 US of the terminal ileum. The outcomes were MRI quality; pathologic findings; level of adverse events; and concordance between endoscopy, MRI, and US estimated by kappa statistics. The ileum and terminal ileum were very good or excellently imaged in approximately 80% of cases. Wall thickening and enhancement were most frequent in the terminal ileum. MRI compared with endoscopy had a sensitivity of 81.8% [95% confidence interval (CI)], specificity of 100%, diagnostic accuracy of 90%, and kappa value of 0.80 (95% CI), indicating a good degree of concordance. A similar degree of concordance was achieved between US and endoscopy. In spite of the frequent adverse reactions, such as diarrhea and nausea, half of the patients were prepared to repeat the examination. The results of MRI are concordant with endoscopy and US of the terminal ileum.