Background: Maintenance of mucosal healing may lead to a better outcome in patients with Crohn's disease (CD). Magnetic resonance diffusion-weighted imaging (MR-DWI) scans 1 year after infliximab (IFX) induction therapy were assessed as predictors of maintained response, or remission, through 3 years of treatment in patients with CD.
Summary: MR-DWI and endoscopy data were prospectively collected throughout IFX treatment. Altogether, 86 lesions from 13 patients given IFX as induction (weeks 0, 2 and 6) and maintenance (5 mg/kg every 8 weeks beginning at week 14) therapy were analyzed with MR-DWI for 0.5-1.5 years from the starting point. Mucosal findings were confirmed by endoscopy at 1 and 3 years (gold standard). Of the 86 lesions, 65 were graded '0' and 21 were graded '1' based on their hyperintensity (HI; or lack thereof) on MR-DWI. Two years after the first evaluation, 7 of 15 false-negative lesions had turned positive based on colonoscopy findings, and 60 of 62 true-negative lesions had not. Thus, 0.03% of those predicted to remain in remission had relapsed (negative predictive value 0.9677, p < 0.0001). MR-DWI-HI at 1 year coincided with the presence of endoscopic inflammation, with sensitivity of 66.67%, specificity of 80.52%, and an area under the curve (AUC) value of 0.7359 (0.5479-0.9240, p = 0.0211). The AUC value of MR-DWI-HI at 3 years was 0.8402 (0.7460-0.9343, p = 0.001) with sensitivity of 94.12% and specificity of 73.91%.
Key message: A definition of the response on the basis of MR-DWI-HI might be helpful for optimizing treatment for patients with CD under treatment with IFX.