Comparison of aspiration and scintigraphic techniques for the measurement of gastric emptying rates of liquids in humans.

A comparison was made of two techniques to measure the rate of gastric emptying. A noninvasive scintigraphic technique using a gammacamera and an invasive aspiration technique based on dye dilution were performed simultaneously. Seven healthy male volunteers each consumed two different liquid meals on two separate occasions. Scintigraphic measurements were performed continuously with aspiration every 10 minutes for a total of one hour. Gastric emptying rates were expressed as slope values after semilog linearisation of the emptying curves. Agreement between the two methods was assessed from the individual differences and mean of the two techniques, as well as from the geometric mean, including 95% limits of agreement. The scintigraphic technique gave a 70% slower emptying rate than the dye dilution technique. However, the 95% limits of agreement are large (1.56 to 0.30), reflecting the small sample size and the large coefficient of variation in the techniques used.