Ileal Crohn's disease: MRI with endoscopic correlation.

Purpose: To evaluate activity staging of Crohn's disease (CD) measured with MR-enterography using ileoscopy as reference standard.

Materials And Methods: A prospective study was made of 61 patients with CD. All patients underwent MR-enterography and ileoscopy. MRI activity was measured by means of an ad hoc developed score, as well as by analysis of the imaging findings, and was compared with the SES-CD score obtained via ileoscopy. Examinations were performed using a 1.0 T scanner.

Results: MRI score discriminates between active and inactive disease with an area under the ROC curve of 0.941. Overall correlation with the standard reference SES-CD score was moderate to strong (Spearman's r=0.62 p<0.001). Agreement between both methods in staging patients with ileal CD as inactive, mild or moderate to severe was good (Cohen's κ=0.60). Differences in means of the MRI activity scores of the three groups showed statistical significance (p<0.01).

Conclusions: The MRI score is a reliable predictor of activity in ileal CD and can stage patients in a way comparable to endoscopy. 1.0 T scans are valid for performing radiological evaluation of ileal Crohn's disease.