Interobserver Agreement in MR Enterography for Diagnostic Assessment in Patients with Crohn's Disease

To evaluate the extent to which MRE can be used as an observer-independent, objective imaging method for the diagnosis and evaluation of CD with respect to the detection of inflammatory changes of the small bowel and lymphadenopathy as diagnostic criterion and bowel distension as a quality criterion.

MRE scans of 84 patients (42 female, median age 37 years) were evaluated independently by 4 experienced radiologists. Analysis of inflammatory changes of the bowel wall, lymphadenopathy and adequate bowel distension was conducted separately for the jejunum, ileum and terminal ileum. The Kendall's W-test was used for the statistical comparison of concordance.

In a total of 55 patients, inflammatory activity of the bowel wall was detected and MRE was found to have a high interobserver reproducibility concerning inflammatory changes of the intestinal wall (Kendall's W 0.527 - 0.823). Concerning lymphadenopathy (31 cases, 36.9 %), a low to moderate consensus could be shown with a Kendall's W value of 0.402 - 0.505. For the assessment of adequate bowel distension, a moderate concordance between the operators could be found (Kendall's W 0.497 - 0.581).

MRE has proven high interobserver agreement with respect to the diagnosis of inflammatory disease activity of the bowel as a diagnostic criterion in patients with CD. Concerning adequate bowel distension as a quality criterion of the examination itself and lymphadenopathy as a diagnostic criterion, moderate interobserver agreement could be found. This is thought to have a rather small effect on the diagnostic significance and conclusiveness of the method in the daily routine.

▶ MR enterography as observer independent diagnostic procedure in patients with Chron's Disease. ▶ Highest interobserver concordance for the criterion of inflammatory bowel wall affection. ▶ Moderate interobserver concordance for lymphadenopathy and bowel distension.