Gastric emptying and motility: assessment with MR imaging--preliminary observations.

PURPOSE To evaluate a magnetic resonance (MR) imaging method for simultaneous assessment of gastric emptying and motility. MATERIALS AND METHODS Gastric emptying and motility were measured in nine volunteers after ingestion of a liquid meal. A specially designed MR imaging protocol was used that allowed simultaneous assessment of gastric emptying (spatial resolution, 1.5 mm; corrected for gastric secretion volume) and gastric motility (temporal resolution, 1.2 seconds; spatial resolution, 3.1 mm). To evaluate the ability to detect small changes in gastric motor activity with findings from this method, the influence of a prokinetic agent (loxiglumide) on gastric emptying and motility was tested in five volunteers. RESULTS Each contraction could be individually visualized at MR imaging. Administration of loxiglumide resulted in decreased gastric half-emptying time (mean +/- 1 standard error of the mean, 88.1 minutes +/- 6.3 for the placebo and 39.1 minutes +/- 6.7 for loxiglumide) and increased gastric motility (contraction frequency, 2.26 contractions per minute +/- 0.15 for the placebo and 3.04 per minute +/- 0.04 for loxiglumide). CONCLUSION MR imaging makes it feasible to study gastric emptying and gastric motility and to determine the influence of drugs on gastric motor activity.