The measurement of gastric emptying: a comparison of fixed scintillation detection and the double-sampling technique

The gastric emptying of a fluid meal was measured simultaneously by fixed scintillation detection and the double-sampling technique in 14 normal subjects and 15 patients who had a vagotomy and drainage procedure. In the normal subjects good correlation was obtained between the two methods but in the operated group there was poor correlation owing to difficulty in measuring the initial rapid emptying phase by fixed scintillation detection. Modification of the fixed scintillation method allows it to be used accurately in postoperative patients. The radioactivity of the meal is measured in vitro before ingestion and this reading is converted, using a constant derived from normal subjects, to a baseline value to which the subsequent in vivo readings are related. This modified technique permits the investigation of gastric emptying of fluid meals in patients with postvagotomy syndromes without the discomfort of a nasogastric tube. The equipment required is inexpensive.