Measurement of gastric emptying by standardized real-time ultrasonography in healthy subjects and diabetic patients

The aim of this study was to simplify and standardize a reproducible, well- tolerated and clinically applicable method for the assessment of gastric em ptying rate by real-time ultrasonography. A total of 33 subjects were exami ned, including 19 healthy subjects and 14 patients with insulin-dependent d iabetes mellitus and clinically suspected delayed gastric emptying. Measure ments of the gastric antrum were taken in the supine position and in relati on to internal landmarks to obtain a standardized cross-sectional image pro ducing the area of a selected slice of the antrum. Diabetic patients were e xamined on the condition that the fasting blood glucose level was 3.5 to 9. 0 mmol/l. Gastric emptying rate was estimated and expressed as the percenta ge reduction in antral cross-sectional area from 15 to 90 min after the ing estion of a standardized semisolid breakfast meal (300 g rice pudding, 330 kcal). Interobserver and intraobserver measurement errors were assessed, as was the significance of age and sex on gastric emptying. in comparison to healthy subjects, diabetic patients showed significantly wider median value s of the 90 min post-prandial antral area, but only a mild tendency toward greater dilation of the gastric antrum prior to and 15 min after meal inges tion. The median value of gastric emptying rate in these diabetic patients was estimated at 29%, which was less than half of that in the healthy subje cts (63%). Statistically the difference was highly significant. interperson al variability of gastric emptying rate and antral areas was large for both groups. Measurements of gastric emptying rate gave highly: reproducible re sults on separate days and from different observers (interobserver systemat ic measurement error 0.3% and random measurement error 10.9%; intraobserver systematic measurement error 3.6% and random measurement error 9.5%). No d ifference in gastric emptying rate was found related to age or sex. We conc lude that the use of standardized real-time ultrasonography to determine ga stric antral: cross-sectional area in a single section of the stomach is a valid method for estimating gastric emptying rate.