The MRI colonic function test: Reproducibility of the Macrogol stimulus challenge

Wilkinson-Smith, Victoria; Menys, Alex; Bradley, Christopher; Corsetti, Maura; Marciani, Luca; Atkinson, David; Coupland, Carol; Taylor, Stuart; Gowland, Penny; Spiller, Robin; Hoad, Caroline

Abstract

Background

Magnetic resonance imaging (MRI) of the colonic response to a macrogol challenge drink can be used to assess the mechanisms underlying severe constipation. We measured the intra-subject reproducibility of MRI measures of colonic function to aid their implementation as a possible clinical test.

Methods

Healthy participants attended for MRI on two occasions (identical protocols, minimum 1 week apart). They underwent a fasted scan then consumed the macrogol drink. Subjects were scanned at 60 and 120 minutes, with maximum value reached used for comparison. The colonic volume, water content, mixing of colonic content and the movement of the colon walls were measured. Coefficients of variation and intraclass correlation coefficients (ICC) were calculated.

Results

12 participants completed the study: 9 female, mean age 26 years (SD 5) and body mass index 24.8kg/m2 (SD 3.2). All measures consistently increased above baseline following provocation with macrogol. The volume, water content and content mixing had good intra-subject reproducibility (ICC volume=0.84, water content=0.93, mixing=0.79, p

• Journal Article Type: Article
• Acceptance Date: Jun 18, 2020
• Online Publication Date: Jul 16, 2020
• Publication Date: 2020-11
• Deposit Date: Jul 8, 2020
• Publicly Available Date: Jul 17, 2021
• Journal: Neurogastroenterology & Motility
• Electronic ISSN: 1365-2982
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 32
• Issue: 11
• Article Number: e13942
• DOI: https://doi.org/10.1111/nmo.13942
• Keywords: Gastroenterology; Physiology; Endocrine and Autonomic Systems
• Public URL: https://nottingham-repository.worktribe.com/output/4754906
• Publisher URL: https://onlinelibrary.wiley.com/doi/full/10.1111/nmo.13942