1. Volume 140, Issue 5, Pages 1454-1463 (May 2011)
A Method to Objectively Assess Swallow Function in Adults With Suspected Aspiration 
Taher I. Omari, Eddy Dejaeger, Dirk van Beckevoort, Ann Goeleven, Geoffrey P. Davidson, John Dent, Jan Tack, Nathalie Rommel 
Gastroenterology 
Volume 140, Issue 5, Pages (May 2011)
DOI: /j.gastro
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2. Figure 1
A summary of the patient cohort according underlying medical pathology and presence of aspiration-penetration as detected on videofluoroscopy.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2011 AGA Institute Terms and Conditions

3. Figure 2
Calculation of pharyngeal swallow variables, pressure at nadir impedance (PNadImp), peak pressure, time from nadir impedance to peak pressure (TNadImp-PeakP), and flow interval. (A) The pressure color iso-contour plot showing first region of interest (1st ROI), used to calculate PNadImp, peak pressure and TNadImp-PeakP, and the second ROI (2nd ROI), used to calculate flow interval. (B) Pressure impedance iso-contour plot for the 1st ROI showing the timing of pharyngeal nadir impedance and peak pressure. (C) Plots of TNadImp-PeakP, PNadImp, and peak pressure with average values shown. (D) Pressure impedance iso-contour plot for the 2nd ROI. (E) The plot of maximum impedance (along y-axis of 2nd ROI) over time (x-axis of 2nd ROI). (F) Impedance cumulative time plot (derived using data in D) showing raw data, the third-order polynomial best fit and the inflexion point of the best-fit curve used to define the flow interval. UES, upper esophageal sphincter.
Gastroenterology  , DOI: ( /j.gastro )
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4. Figure 3
Box plot showing median and interquartile ranges for first swallow Swallow Risk Index in controls and patients. Patient data are further stratified based on aspiration score. No aspiration = score 1, penetration = score 2–5, and aspiration = score 6–8. Gray circles show the data from individual swallows. Groups were compared using Kruskal-Wallis 1-way analysis of variance (ANOVA) on ranks and pair-wise multiple comparison procedures (Dunn's method).
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2011 AGA Institute Terms and Conditions

5. Figure 4
(A) Correlation of patient average aspiration score with average first swallow Swallow Risk Index (SRI). (B) κ Agreement between individual and average first swallow SRI cutoff values and the presence/absence of aspiration-penetration during fluoroscopy. An ROC curve for individual and average first swallow SRI is shown also in graphs (C) and (D), respectively.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2011 AGA Institute Terms and Conditions

6. Figure 5
Example tracings of first swallows (10 mL liquid) recorded in a control subject and 2 patients (individual results for pharyngeal variables and aspiration-penetration scores are shown in Figure 6). (A) A 39-year-old asymptomatic male control. (B) A 58-year-old man who developed symptoms post-anterior cervical fusion (C5–C6) surgery in whom fluoroscopy demonstrated high obstruction and no evidence of aspiration (aspiration-penetration score 1). (C) A 57-year-old stroke patient (male, right hemisphere) who had continuous signs of aspiration on liquids and in whom fluoroscopy demonstrated aspiration (aspiration-penetration score 7). Top row: Color iso-contour plots of pressure only. Second row: Pressure-impedance iso-contour plots showing pressure as lines (10 mm Hg iso-contours) with impedance superimposed (color iso-contour showing impedance levels < 1 median standardized units [msu]). Iso-contour plots of pressure within the dotted box are in the third row. In these plots dotted and solid lines define the timing of nadir impedance (NadImp) and the timing of peak pressure, respectively. UES, upper esophageal sphincter.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2011 AGA Institute Terms and Conditions

7. Figure 6
Comparison of pharyngeal variables and aspiration-penetration scores for the 3 subjects for which data from sample individual swallows are shown in Figure 5. Individual data for peak pressure, pressure at nadir impedance (PNadImp), time from nadir impedance to peak pressure (TNadImp-PeakP), flow interval, aspiration–penetration score and Swallow Risk Index (SRI) are shown. The Patient Average SRI is based on the average of all first swallows recorded in each subject (diagnostic cutoff of ≥15 = aspiration-penetration). Control ranges for each variable are shown by gray shading; abnormal findings compared to controls are indicated as black bars. For graphs comparing patient average SRI, the gray line indicates the optimal cutoff criteria. NOTE: Obstruction patient B, compared to stroke patient C, had a normal peak pressure but elevated PNadImp. Stroke patient C had a mean TNadImp-PeakP <0 (ie, on average nadir impedance occurred after peak pressure), this is suggestive of highly ineffective bolus propulsion in advance of the pharyngeal stripping wave. Stroke patient C had the highest average SRI, which exceeded our cutoff of 15. This is consistent with fluoroscopy findings of aspiration in patient C. UES, upper esophageal sphincter.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2011 AGA Institute Terms and Conditions