Quantified small bowel motility assessment on magnetic resonance enterography in paediatric inflammatory bowel disease - does it reflect clinical response?

Background: Quantified small bowel motility assessment using cine magnetic resonance enterography (MRE) has shown promise as a biomarker in adult inflammatory bowel disease. Whether quantified motility corresponds to treatment response in paediatric inflammatory bowel disease is unknown.
Objective: To test whether changes in motility reflect response.
Materials and Methods: Local ethics approval was granted for this single-institution, retrospective study. All children < 18 years with confirmed inflammatory bowel disease, who had more than one MRE between Jan 2011-Jan 2022, were included. Simplified MaRIA (sMaRIA) and motility index (quantified motility) at all terminal ileum and diseased non-terminal ileum segments were independently assessed by two radiologists each with ≥ 9 years' experience. Change in (Δ) motility index was compared to clinical (gastroenterologist physician's global assessment) and consensus radiological reference standard (response = decrease in sMaRIA of more than or equal to 2 points) in responders versus non-responders using the Mann-Whitney test. Sensitivity and specificity of Δ motility index more than zero were compared to decrease in sMaRIA of 2 or more points for identifying clinical response.
Results: Of 64 children aged 5-16, 21 out of 64 (33%) were responders, 37 out of 64 (58%) were non-responders and 6 out of 64 (9%) had inactive disease according to clinical reference standard. Δ Motility index by both radiologists was higher in responders (+ 16, + 39) than non-responders (-43, -44), P = 0.04, P = 0.01 each radiologist, respectively. Motility index was more sensitive (57% versus 24%), but less specific (67% versus 93%) than sMaRIA in identifying clinical response.
Conclusion: Motility index on cine MRE corresponds to clinical response, and is more sensitive at detecting response compared to sMaRIA in paediatric inflammatory bowel disease.
Competing Interests: Declarations. Conflicts of interest: The authors of this manuscript declare relationships with the following companies: Motilent Ltd as follows: HEF – previous internship. SAT – Holds share options.
(© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)