Magnetic resonance Index of Activity (MaRIA) is reliable in assessing response to treatment in patients with Crohn's disease (CD).

AIM: To assess the accuracy of Magnetic Resonance Index of Activity (MaRIA) in evaluating therapeutic efficacy in Crohn's disease (CD) patients with different activity levels using ileocolonoscopy as the reference standard. MATERIALS AND METHODS: Forty-eight patients underwent magnetic resonance enterography (MRE) and ileocolonoscopy at baseline, week 26, and week 52, along with the Simple Endoscopic Score for Crohn's Disease (SES-CD) and MaRIA scores. According to the SES-CD score at baseline, all patients were subdivided into mild, moderate, and severe activity subgroups. The identification of endoscopic mucosal healing (MH) was explored primarily. Moreover, the Crohn's Disease Activity Index (CDAI), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), and interleukin-6 (IL-6) levels were collected and analysed. RESULTS: MaRIA correlated significantly with SES-CD and CRP at baseline, week 26, and week 52. The discrepancies in MaRIA and SES-CD were statistically significant before and after treatment. MaRIA = 24.43 and ΔMaRIA = 12.77 as the cut-off points were found to have high diagnostic accuracy for predicting MH. MaRIA (p<0.001), SES-CD (p<0.001), CRP (p<0.05), ESR (p<0.05), and CDAI score (p<0.05) in patients with MH were considerably decreased compared to those in patients without MH. CONCLUSIONS: MRE has good application value in evaluating the therapeutic response of CD patients treated with biological agents. MaRIA is a reliable indicator in the follow-up of CD patients, which is strongly correlated with SES-CD, and it has high accuracy in predicting endoscopic MH.