Coordinate mapping of hyolaryngeal mechanics in swallowing.
Characterizing hyolaryngeal movement is important to dysphagia research. Prior methods require multiple measurements to obtain one kinematic measurement whereas coordinate mapping of hyolaryngeal mechanics using Modified Barium Swallow (MBS) uses one set of coordinates to calculate multiple variables of interest. For demonstration purposes, ten kinematic measurements were generated from one set of coordinates to determine differences in swallowing two different bolus types. Calculations of hyoid excursion against the vertebrae and mandible are correlated to determine the importance of axes of reference. To demonstrate coordinate mapping methodology, 40 MBS studies were randomly selected from a dataset of healthy normal subjects with no known swallowing impairment. A 5 ml thin-liquid bolus and a 5 ml pudding swallows were measured from each subject. Nine coordinates, mapping the cranial base, mandible, vertebrae and elements of the hyolaryngeal complex, were recorded at the frames of minimum and maximum hyolaryngeal excursion. Coordinates were mathematically converted into ten variables of hyolaryngeal mechanics. Inter-rater reliability was evaluated by Intraclass correlation coefficients (ICC). Two-tailed t-tests were used to evaluate differences in kinematics by bolus viscosity. Hyoid excursion measurements against different axes of reference were correlated. Inter-rater reliability among six raters for the 18 coordinates ranged from ICC = 0.90 - 0.97. A slate of ten kinematic measurements was compared by subject between the six raters. One outlier was rejected, and the mean of the remaining reliability scores was ICC = 0.91, 0.84 - 0.96, 95% CI. Two-tailed t-tests with Bonferroni corrections comparing ten kinematic variables (5 ml thin-liquid vs. 5 ml pudding swallows) showed statistically significant differences in hyoid excursion, superior laryngeal movement, and pharyngeal shortening (p < 0.005). Pearson correlations of hyoid excursion measurements from two different axes of reference were: r = 0.62, r2 = 0.38, (thin-liquid); r = 0.52, r2 = 0.27, (pudding). Obtaining landmark coordinates is a reliable method to generate multiple kinematic variables from video fluoroscopic images useful in dysphagia research.
Medical College of Georgia, Georgia Regents University.
Thomas Z
TZ
Thompson
Medical College of Georgia, Georgia Regents University.
Farres
F
Obeidin
Department of Communicative Sciences and Disorders, New York University.
Alisa A
AA
Davidoff
Medical College of Georgia, Georgia Regents University.
Cody L
CL
Hightower
Medical College of Georgia, Georgia Regents University.
Christohper Z
CZ
Johnson
Medical College of Georgia, Georgia Regents University.
Sonya L
SL
Rice
Medical College of Georgia, Georgia Regents University.
Rebecca-Lyn
RL
Sokolove
Medical College of Georgia, Georgia Regents University.
Brandon K
BK
Taylor
Medical College of Georgia, Georgia Regents University.
John M
JM
Tuck
Department of Cellular Biology & Anatomy, Georgia Regents University; Department of Otolaryngology, Georgia Regents University; wpearson@gru.edu.
William G
WG
Pearson
D001696:Biomechanical Phenomena; D003679:Deglutition / Q000502:physiology*; D006801:Humans; D006928:Hyoid Bone / Q000033:anatomy & histology* / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D007830:Larynx / Q000033:anatomy & histology* / Q000502:physiology*; D012016:Reference Values; D012984:Software