ABSTRACT
BACKGROUND AND OBJECTIVES: Scintigraphic swallowing test is a noninvasive, quantitative and safe measurement of swallowing. The purposes of this study were to establish a normative data of scintigraphic swallowing test and to determine that this procedure could be a simple screening test of swallowing disorders. MATERIALS AND METHODS: Scintigraphic tests of the oropharyngeal transit with thick liquid bolus were performed in 51 normal subjects, who were 15 to 61 years of age. Each subject was instructed to swallow the single viscous liquid bolus mixed with 1mCi Tc-99m tin-colloid. Dynamic imaging data were obtained with the patients in a supine position and recorded at a frame rate of 25 per second over 10 seconds. Inspection of summed images permitted the section of regions of interest (ROI) to represent the mouth, pharynx, and esophagus. Transit times between each ROI were calculated and compared. Time activity data were used to compute oral discharge and pharyngeal transit times, oropharyngeal transit time, percentage residues in the mouth and pharynx, oral and pharyngeal swallowing efficiencies, and oropharyngeal clearance in 2.5 seconds. Twenty subjects repeated the test in two weeks. RESULTS: Mean+/-standard deviation of oral discharge time, pharyngeal transit time, oropharyngeal transit time, oral residue, pharyngeal residue, oral swallowing efficiency, pharyngeal swallowing efficiency, and oropharyngeal clearance in 2.5sec were 0.37+/-0.11sec, 0.64+/-0.19 sec, 1.01+/-0.21 sec, 7.05+/-3.60%, 6.12+/-3.80%, 273.58+/-78.82%/sec, 160.74+/-51.11%/sec, and 90.63+/-6.65% respectively. Repeated studies in 20 individuals indicated that these parameters were statistically similar and pharyngeal transit time was highly reproducible. Other parameters were intermediately reproducible except oral and pharyngeal residues. CONCLUSION: Oropharyngeal scintigraphy provides a rapid, noninvasive and cost effective screening test as well as a quantitative study of swallowing disorders.