Scintigraphic measurement of gastric emptying and ultrasonographic assessment of antral area: relation to appetite

Abstract

Background: Ultrasound measurement of gastric emptying has potential advantages over scintigraphy, but there is little information about its accuracy.

Aims: The relation between ultrasonographic measurements of antral area and (a) scintigraphic measurements of gastric emptying and intragastric distribution of liquids (b) postprandial satiation, were evaluated.

Subjects: Seven normal volunteers were studied.

Method: Each subject drank 75 g dextrose dissolved in 350 ml of water (300 kcal) or beef soup (20 kcal), both labelled with technetium-99m sulphur colloid on separate days and had measurement of gastric emptying by scintigraphy and ultrasound.

Results: Scintigraphic and ultrasound 50% emptying times (T50s) were comparable and longer (p < 0.001) for dextrose than soup mean (SEM) (dextrose 107 (16) min v 108 (18) min, soup 24 (4) min v 23 (5) min). There were close correlations between scintigraphic and ultrasound T50s (dextrose r = 0.94, p < 0.005, soup r = 0.97, p < 0.001) and between the time at which the distal stomach content decreased from its maximum value by 50% (measured scintigraphically) and the ultrasound T50 (dextrose r = 0.95, p < 0.005, soup r = 0.99, p < 0.0001). In contrast, there was no significant relation between the distal stomach content when expressed as a percentage of the maximum content in the total stomach and the ultrasound T50. After dextrose, fullness was related (r = 0.92, p < 0.01) to the postprandial increase in antral area measured by ultrasound.

Conclusions: Ultrasound measurements of gastric emptying are: (a) of comparable sensitivity to scintigraphy in quantifying emptying of both low and high nutrient liquids (b) correlate with postprandial satiation, suggesting that the latter may be mediated by antral distension.