Scintigraphic study of duodenogastric reflux. Value of a computerized image-subtraction method.

Duodenogastric reflux (DGR) could be implicated in several esophageal and gastric diseases. Establishing its pathophysiological role however is difficult because of the problems in the demonstration and quantification of DGR episodes. The aim of this study was to improve a scintigraphic method of detection and quantification of DGR episodes during the postprandial period in man. The study was carried out in 14 control subjects (7 males and 7 females, median age = 25 years, range: 22-35 years). As scintigraphic recording was continuous during 150 min, all DGR episodes were revealed. In order to improve visual detection of DGR episodes, images were treated by a computerized image subtraction method. The visual detection limit of DGR episodes determined by comparison to test images was 0.6 p. 100 of the dose injected intravenously or 17 microCi. A DGR episode was demonstrated in one of the 14 control subjects. The quantity of refluxed liquid was estimated, in this case, at 30 microCi, and the duration of the reflux greater than 2 min. Continuous scintigraphic recording in association with a computer based technique of image subtraction seems to improve scintigraphic performance in the study of DGR episodes under pathological conditions.