Comparison of MR enterography and histopathology in the evaluation of pediatric Crohn disease

While MR enterography (MRE) is commonly used to identify segments of bowel affected by Crohn disease in children, there is little data to support this practice. To assess the ability of MRE to identify segments of small bowel and colon affected by pediatric Crohn disease using histopathology as the reference standard. Pediatric MRE examinations performed between April 2009 and December 2010 were identified. Subjects were excluded if they did not have Crohn disease, if they had Crohn disease but no correlative histopathology within 2 months of imaging, or if they had undergone prior bowel resection. Pertinent MRE and histopathology reports were reviewed, and normal and abnormal bowel segments were documented. Thirty-two pediatric MRE examinations were identified with correlative histopathology. MRE had an overall sensitivity of 94% for detecting the presence of Crohn disease, in general. At the bowel segmental level, MRE had a sensitivity of 66%, specificity of 90%, positive predictive value of 85% and negative predictive value of 76%. The terminal ileum was abnormal by MRE in 11 of 15 (73%) subjects lacking a diagnostic biopsy of this bowel segment. MRE successfully identifies small bowel and colon segments affected by pediatric Crohn disease.