title: Gastric motor function and emptying in the right decubitus and seated body position as assessed by magnetic resonance imaging.
abstract: OBJECTIVE
  To determine the effect of the right decubitus lying body position (RP) on relevant parameters of human gastric motor function in healthy volunteers.
  
  
  METHODS
  Postprandial gastric function after ingestion of a solid/liquid meal (150 g/150 mL) was assessed over 90 minutes in volunteers in the RP and seated position (SP). Ten healthy volunteers were imaged using two MRI systems that differed in architecture and field strength. Stomach and intragastric air volume, intragastric meal distribution, gastric emptying, and gastric peristalsis were compared between the RP and SP.
  
  
  RESULTS
  Body position did not affect gastric relaxation (RP, 372 mL vs. SP, 384 mL) and initial gastric volumes (stomach: RP, 458 mL vs. SP, 462 mL; meal: RP, 377 mL vs. SP, 399 mL; intragastric air: RP, 110 mL vs. SP, 98 mL). Postprandial stomach volume and gastric activity (RP and SP, 3.1 minute(-1)) were also similar. Meal emptying showed different characteristics, resulting in a significant but small difference in meal volume of -43 mL at t = 90 minutes (P < 0.05).
  
  
  CONCLUSIONS
  Gastric MRI in RP is feasible for clinical research assessing gastric motor function. The subtle difference in meal emptying may be induced by posture-dependent vagal activity. This study confirms that MRI is a highly sensitive imaging technique for assessing gastrointestinal function in humans.
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, CH-8092 Zurich, Switzerland.
authors.forename: Reto
authors.initials: R
authors.lastname: Treier
authors.forename: Andreas
authors.initials: A
authors.lastname: Steingoetter
authors.forename: Dominik
authors.initials: D
authors.lastname: Weishaupt
authors.forename: Oliver
authors.initials: O
authors.lastname: Goetze
authors.forename: Peter
authors.initials: P
authors.lastname: Boesiger
authors.forename: Michael
authors.initials: M
authors.lastname: Fried
authors.forename: Werner
authors.initials: W
authors.lastname: Schwizer
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010528:Peristalsis / Q000502:physiology; D019518:Postprandial Period; D011187:Posture / Q000502:physiology*