Gastroesophageal reflux scintigraphy: interpretation methods and inter-reader agreement.

Background: Scintigraphic imaging is a useful screening tool for patients with suspected gastroesophageal reflux. New scintigraphic interpretation methods have recently been introduced. This study was undertaken to evaluate the efficiency of various scintigraphic interpretation methods in the detection of gastroesophageal reflux and to measure their influence on inter-reader agreement.

Methods: Scintigraphic images of 49 children with suspected gastroesophageal reflux were interpreted by three different methods: visual interpretation, time activity curves, and condensed images. The readings were performed by three specialists and a resident. The discordant results were resolved by a consensus reading done together by all interpreters based on the three different methods. The gastroesophageal refluxes were grouped according to their number, location and intensity.

Results: Gastroesophageal reflux scintigraphy revealed 22 patients with negative results and 27 with positive results. The sensitivity, positive predictive value and specificity for each of the three specialists vs. the resident were 96%, 96% and 81% vs. 96%; 93%, 90% and 96% vs. 81%; and 90%, 86%, and 95% vs. 73%, respectively. The mean inter-observer reproducibility (κ value) was 0.910 for visual interpretation, 0.652 for time activity curves and 0.789 for condensed images. Twenty-seven percent of the results were discordant and most of these refluxes were of low grade (92%), low intensity (77%) and localization in the distal esophagus (54%).

Conclusion: Gastroesophageal scintigraphy is a useful tool for detecting patients with suspected reflux, and visual interpretation is better than the other two methods in terms of accuracy and inter-observer reproducibility.