Quantification of distal antral contractile motility in healthy human stomach with magnetic resonance imaging.
OBJECTIVE
To quantify healthy postprandial: 1) propagation, periodicity, geometry, and percentage occlusion by distal antral contraction waves (ACWs); and 2) changes in ACW activity in relationship to gastric emptying (GE).


METHODS
Using 1.5-T MR scanner, nine healthy fasted volunteers were examined in the right decubitus position after ingestion of 500 mL of 10% glucose (200 kcal) with 500 microM Gd-DOTA. Total gastric (TGV) and meal volumes (MV) were assessed every five minutes for 90 minutes, in and interspersed with dynamic scan sequences (duration: 2.78 minutes) providing detailed images of distal ACWs.


RESULTS
TGV increased by 738+/-38 mL after ingestion (t0), subsequently decreasing in parallel to GE. The mean GE rate and half-emptying time were 24+/-3 mL/5 minutes and 71+/-6 minutes, respectively. Accompanying ACWs reached a periodicity of 23+/-2 seconds at t35 and propagated at an unvarying speed of 0.27+/-0.01 cm/second. Their amplitude of 0.70+/-0.08 cm was constant, but the width decreased along the antral wall by 6+/-2%/cm (P=0.003). ACWs were nonocclusive (percentage occlusion 58.1+/-5.9%, t0 at the pylorus) with a reduction in occlusion away from the pylorus (P<0.001). No propagation and geometry characteristics of ACWs correlated with the changes of MV (mL/5 minutes; R2<0.05).


CONCLUSIONS
Our results indicate that ACWs are not imperative for emptying of liquids. This study provides a detailed quantitative reference for MRI inquiries into pharmacologically- and pathologically-altered gastric motility.
Kwiatek
Monika A
MA
Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland. monika.kwiatek@gmail.com
Steingoetter
Andreas
A
Pal
Anupam
A
Menne
Dieter
D
Brasseur
James G
JG
Hebbard
Geoffrey S
GS
Boesiger
Peter
P
Thumshirn
Miriam
M
Fried
Michael
M
Schwizer
Werner
W
D000328:Adult; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D005769:Gastrointestinal Motility / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D009130:Muscle, Smooth / Q000502:physiology; D019518:Postprandial Period / Q000502:physiology*; D011706:Pyloric Antrum / Q000502:physiology*; D012016:Reference Values; D013270:Stomach / Q000502:physiology