Combination of colonoscopy and magnetic resonance enterography is more useful for clinical decision making than colonoscopy alone in patients with complicated Crohn's disease.

Background/aims: The small bowel is affected in more than half of patients with Crohn's disease (CD) at the time of diagnosis, and small bowel involvement has a negative impact on the long-term outcome. Many patients reportedly have active lesions in the small intestine even in patients in clinical remission. This study was performed to compare findings of magnetic resonance enterography (MRE) and ileocolonoscopy.

Methods: A single-center retrospective study was conducted in 50 patients (60 imaging series) with CD, for whom MRE was additionally performed during the bowel preparation for subsequent ileocolonoscopy. Endoscopic remission was defined as a Simple Endoscopic Score for CD (SES-CD) of <5. MRE remission was defined as a Magnetic Resonance Index of Activity (MaRIA) score of <50. The time to treatment escalation was assessed by the log-rank test.

Results: Importantly, 7 of 29 patients (24.1%) with endoscopic remission had a MaRIA score of ≥50. Both SES-CD and MaRIA correlated with the need for treatment escalation (P = 0.025, P = 0.009, respectively). MRE predicted the need for treatment escalation even in patients with endoscopic remission. Although no correlation was present between SES-CD and MaRIA score in patients with structuring/penetrating disease, or insufficient ileal insertion (<10cm), a high MaRIA score still correlated with the need for treatment escalation in stricturing or penetrating disease (P = 0.0306).

Conclusions: The MaRIA score predicts the need for treatment escalation even in patients with endoscopic remission, indicating that addition of MRE to conventional ileocolonoscopy alone can be a useful, noninvasive tool for monitoring CD especially in stricturing or penetrating disease.