Small bowel motility assessment with magnetic resonance imaging.

Purpose: To assess primarily the feasibility of magnetic resonance imaging (MRI) as a tool to monitor small bowel peristaltic motion and secondarily to validate this technique by demonstrating drug-induced motility changes.

Materials And Methods: After a standardized oral preparation of Ispaghula husk (Metamucil) and meglumine gadoterate (Gd-DOTA; Dotarem), 10 volunteers underwent dynamic MRI using a two-dimensional turbofast field echo (TFE) sequence with a slice repetition time of 500 msec. Intraluminal cross-sectional caliber changes over time were assessed allowing quantification of the peristaltic frequencies and amplitudes of the small gut on various regions of interest. Pharmacologically induced alterations of the peristaltic motion after spasmolytics and gastrokinetic motion enhancers were investigated.

Results: Small bowel diameter measurement resulted in a peristalsis of 10.96 (SD = +/-2.51) waves per minute, oscillating regularly with mean amplitudes of 6.65 mm (SD = +/-1.15 mm). Peristaltic frequency in normal individuals is consistent with that observed with other techniques. Intravenous administration of scopolamine butylbromide (= hyoscine butylbromide/Buscopan) resulted in small bowel paralysis within 21.3 seconds (SD = +/-2.8 seconds). Prokinetic effect of intravenous metoclopramide (Paspertin) after Buscopan paralysis was tested in one volunteer, characterized by a slow recovery of peristalsis, which propagated from the proximal to the distal segments and enhanced contraction amplitudes.

Conclusion: Dynamic MRI allows observing and quantifying small bowel peristalsis, characterizing motion patterns, and monitoring the effects of interfering factors such as drugs.