Detecting the effects of a standardized meal challenge on small bowel motility with MRI in prepared and unprepared bowel

Abstract

Objective MRI is increasingly used to evaluate small bowel contractility. The objective of this study was to validate a clinically practical stimulation test (300‐kcal meal) for small bowel motility. Methods Thirty‐one healthy subjects underwent dynamic MRI to capture global small bowel motility after ±10h fasting, of which 15 underwent bowel preparation consisting of 1 L 2.5% mannitol solution and 16 did not. Each subject underwent (1) a baseline motility scan (2) a food challenge (3) a post‐challenge scan, and (4) second post‐challenge scan (after ±20 minutes). This protocol was repeated within 2 weeks. Motility was quantified using a validated motility assessment technique. Key Results Motility in prepared subjects at baseline was significantly higher than motility in unprepared subjects (0.36 AU vs 0.18 AU, P < 0.001). In the prepared group, the food challenge produced an 8% increase in motility (P = 0.33) while in the unprepared subjects a significant increase of 30% was observed (P < 0.001). Responses to food remained insignificant (P = 0.21) and significant (P = 0.003), for the prepared and unprepared subjects, respectively, ±20 minutes post food challenge. These results were confirmed in the repeated scan session. Conclusion & Inferences A significant response to a 300‐kcal meal was measured within 10 minutes in unprepared bowel, supporting the clinical use of this challenge to provoke and assess motility changes. A caloric challenge did not produce an observable increase in motility in mannitol prepared subjects.

Assessment of fasted and fed gastrointestinal contraction frequencies in healthy subjects using continuously tagged MRI

“…No differences were found in the higher frequency range (11)(12)(13)(14)(15)(16)(17)(18)(19) contractions per minute), which primarily contains breathing motion, with an exception at 20 contraction per minute. No differences were found in the higher frequency range (11)(12)(13)(14)(15)(16)(17)(18)(19) contractions per minute), which primarily contains breathing motion, with an exception at 20 contraction per minute.…”

“…In a previous study, 15 In the study presented here, the same healthy subjects were included as in the study referred to above, but the fundamental different approach is to monitor motility at substantially longer timescales (3 minutes vs. 20 seconds) and examine motility behavior in the frequency domain. The tagged MRI acquisition technique in combination with the frequency analysis showed a mean effect ranging from 10% to 19% over nine spectral intervals (2-10 cpm).…”

“…15,17 For inclusion in this study, we selected all participants that did not receive bowel preparation, resulting in the enrollment of sixteen healthy subjects. The study was designed to gain insight in healthy bowel motility quantified with MRI.…”

“…This allows assessment of the response by comparing pre-and poststimulation, this response may be altered in disease. 15,16 The ability to quantify the spectrum of frequencies in the intestine with MRI and capture the presence or absence of specific frequencies after a stimulation challenge could distinguish healthy from diseased bowel motility.…”

“…The study was designed to gain insight in healthy bowel motility quantified with MRI. 15,17 For inclusion in this study, we selected all participants that did not receive bowel preparation, resulting in the enrollment of sixteen healthy subjects. Inclusion criteria included healthy, human volunteers who were willing to undergo minimal bowel preparation and MRI.…”