The relationship between observations and measures of oral and pharyngeal residue from videofluorography and scintigraphy

Abstract

We examined measures of oral and pharyngeal residues from scintigraphic studies and estimates/observations from videofluorographic (modified barium swallow) studies taken on the same day but not concurrently in 16 dysphagic patients of varying etiologies presenting with oral and/or pharyngeal dysphagia. Oral and pharyngeal residuals following the swallow were quantified scintigraphically and were then compared with measures of residuals obtained from the modified barium swallow. Estimates of oral and pharyngeal residues from the modified barium swallows were generated by a trained observer who was blinded to the scintigraphic data. Positive and significant Spearman correlations between oral and pharyngeal residue measures from scintigraphy and observations of oral and pharyngeal residues from modified barium swallows were found. This supports the validity of observations of oral and pharyngeal residues in clinical studies. Limitations of these observations are discussed.

Fig. 1

Oral and pharyngeal regions of interest (ROI) were defined by radioactive skin markers placed over the posterior tonsillar pillar, hyoid bone and inferior margin of the cricoid cartilage (see text).

Fig. 2

Shown schematically are oral and pharyngeal time–activity curves depicting parameters used to calculate regional postswallow residuals (a) and transit times (b). (a) Oral residual, expressed as a percent of preswallow counts. (b/a × 100%). Pharyngeal residual, expressed as a percent of counts delivered to the pharynx and corrected for background counts [(c−d)/(a−b × 100%] a = oral counts from bolus preswallow; b = postswallow oral residual counts; c = post swallow pharyngeal residual counts; d = preswallow background counts from pharyngeal region. (b) Oral transit time = B−A seconds, pharyngeal transit time = C−B seconds, and pharyngeal clearance time = C−A seconds. Pharyngeal clearance time is the interval from the first entry of the bolus head into the pharynx until the exit of the bolus tail from the hypopharynx. A = onset of oral emptying; B = completion of oral emptying; C = completion of pharyngeal emptying.

Fig. 3

Plots of percent oral residue (ORES) (a and c) and percent pharyngeal residue (PRES) (b and d) as measured from scintigraphy and observed from videofluorography on 5-ml (a and b) and 10-ml (c and d) liquid boluses.

Fig. 4

Bland–Altman plots of the similarities of the oral (ORES) (a and c) and pharyngeal residue (PRES) (b and d) for 5-ml (a and b) and 10-ml (c and d) boluses. Horizontal lines for the mean difference and for ±1.96 standard deviations of the difference are plotted in the graph.