Measurement of gastric emptying time--a comparative study between nonisotopic aspiration method and new radioisotopic technique.

A comparative study between modified conventional saline load test and the more recently introduced radioisotopic method was run in 8 normal volunteers. Each subject underwent at least three studies by each of the two methods: (1) aspiration method of Goldstein and Boyle incorporating our modification, and (2) an isotopic method employing a gamma camera with a computer. A liquid meal of isotonic saline was used with or without99mTcDTPA. The results indicated that the gastric emptyingT1/2 (8.8±3.5 min) obtained by saline load test was shorter than that obtained by isotopic method (12±3 min). This discrepancy was most likely due to inherent error (incomplete aspiration of the gastric fluid) in the former method giving rise to a false faster emptying time. Moreover, the variations inT1/2 value in the same individual was much more in the aspiration method than it was in the isotopic method.