Evaluation of a solid bolus suitable for esophageal scintigraphy

This study was designed to select a suitable solid bolus for esophageal scintigraphy. Optimally, a bolus should leave minimal residual buccal and pharyngeal activity after being swallowed. We compared the oropharyngeal behavior of three boluses, i.e., omelette, egg white, and paté of 1- and 3-ml volume. Thirty patients without dysfunction of the upper esophageal sphincter were recruited for the study. Scintigraphy interpretation was based on the results of condensed images and time activity curves. A total of 108 oropharyngeal transits were analyzed. First we determined the most appropriate volume (1 or 3 ml) of paté, omelette, and egg white (i.e., the volume with the least residual oropharyngeal activity). Buccal or pharyngeal bolus retention occurred significantly less frequently with 1 ml paté than 3 ml (p = 0.03) and also less frequently with 3 ml egg white than with 1 ml egg white (p = 0.03), and the mean buccal bolus retention index was lower using 3 ml omelette than 1 ml omelette (p = 0.03). Then we identified the most suitable of the three selected boluses. Both oral and pharyngeal residues were higher for paté (1 ml) than for omelette (p = 0.02 and 0.05), and pharyngeal residue was significantly lower for omelette (3 ml) than for egg white (3 ml) (p = 0.02). In conclusion, a 3-ml bolus of radiolabeled omelette seems to be the most suitable bolus for exploration of esophageal transit, and its use could enhance the potential of scintigraphy in the assessment of esophageal disorders.