SCINTIGRAPHY VERSUS PH PROBE FOR QUANTIFICATION OF PEDIATRIC GASTROESOPHAGEAL REFLUX - A STUDY USING CONCURRENT MULTIPLEXED DATA AND ACID FEEDINGS

We performed 12 simultaneous scintigraphic and pH probe studies in chi ldren being evaluated for reflux to determine the ability of scintigra phic images in comparison to pH probe data to quantify gastroesophagea l reflux in children and to identify an optimal scintigraphic framing interval. We used a multiplexor to synchronize exactly the scintigraph y and pH probe and an acid meal to avoid missing postprandial episodes with the pH probe. We reformatted the studies in both 60-sec and 10-s ec images to compare the two framing intervals. The 60-sec images prod uced better agreement between pH probe and scintigraphy than the 10-se c images for both the number of reflux episodes and the duration of re flux. Of the 64 reflux episodes detected by either method at this coar ser framing interval, scintigraphy detected 80%, the pH probe detected 63% and both methods concurrently detected 42%. Of the 681 60-sec ima ges aggregated across patients, scintigraphy detected 55% of those wit h intraesophageal refluxate, the pH probe detected 96% and both tests concurrently detected 51%. Within patients, the number of positive sci ntigraphic images in the postprandial hour correlated with the number of images with pH < 4 during the same hour (p = 0.008, and p < 0.0001 if two patients with very rapid gastric emptying are excluded), but no t with the results of the 24-hr pH probe study. A 1-hr scintigraphic s tudy formatted in 60-sec frames provides a quantitative representation of postprandial gastroesophageal reflux for children, particularly if they do not have rapid gastric emptying.