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

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.