When Intestinal Ultrasound and MRI Disagree in Crohn’s Monitoring
A prospective multicentre comparison found only fair-to-moderate agreement between intestinal ultrasound and MR enterography for treatment response.
Two views of the bowel wall
Intestinal ultrasound (IUS) and magnetic resonance enterography (MRE) are both used to assess Crohn’s disease. They offer different practical and technical views of the bowel, so a change detected by one method may not map neatly to a change detected by the other.
A prospective, blinded, multicentre analysis compared the two modalities before and after treatment in people with endoscopically active disease. Thirty-five participants were included in the response analysis.
Agreement was not complete
At baseline, IUS identified more bowel segments classified as active than MRE in this study: 59 versus 42. Agreement for disease location and behaviour was moderate. For treatment response, agreement ranged from fair to moderate, depending on the MRI activity score used. Normalisation of bowel-wall thickness was recorded in 12 participants by MRE and 11 by IUS, with moderate agreement between those assessments.
These results do not establish that either modality is universally superior. They show that the choice of measure and the definition of response affect the comparison. In practice, a clinician may need to interpret imaging alongside symptoms, laboratory tests, endoscopy, and the treatment question being asked.
A cautious interpretation
The analyzed group was small, and agreement statistics describe how often measurements align—not whether either method is a perfect reference standard. The paper supports careful, method-aware interpretation rather than treating IUS and MRE scores as interchangeable.
Further studies with larger cohorts and consistent response definitions can help establish where each modality is most useful, including whether one can reduce burden without losing clinically important information.
Source and credit
Independent summary of “Assessment of transmural treatment response in known Crohn’s disease: a prospective blinded study of the intermodality agreement between intestinal ultrasound and magnetic resonance enterography,” BMJ Open Gastroenterology, published 9 February 2026. Original paper, DOI: 10.1136/bmjgast-2025-002175. Source article license: CC BY-NC 4.0. No source figures or tables are reproduced here.
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