Speech and Hearing Sciences ETDs

Publication Date

Summer 7-19-2020


INTRODUCTION: Dysphagia, or a disordered swallow, affects up to 1 in 25 individuals in the United States. The gold standard for assessing dysphagia is the videofluoroscopic evaluation of swallowing (VFES). This allows the clinician to observe the swallow anatomy in motion via an X-ray movie, which historically was recorded at 30 frames per second. In recent years VFES have been performed at less frames per second due to radiation concern. This project investigates the effect of using lower temporal resolutions on assessment of video-fluoroscopic swallow studies.

METHODS: In this investigation, 30 swallow studies, all acquired at 30 frames per second, were obtained from a repository at Presbyterian Hospital, with 6 studies chosen per each of the five categories of the international dysphagia diet to reflect varied levels of dysphagia. These studies were altered to simulate 15 and 5 frames per second. Temporal and kinematic measures were determined for thin and pudding/puree swallows per study at each of the 3 frame rates. Temporal measures included pharyngeal transit time (PTT), pharyngeal delay time (PDT), and duration of upper esophageal sphincter opening (UESOD). Kinematic measures included extent of hyolaryngeal elevation (HLE)


and extent of upper esophageal sphincter opening (UESOE). A panel of 3 experienced speech—language pathologists viewed each study at the three frame rates in randomized order, without being given any indication as to frame rate per study. Each panel member gave their ratings of safety, efficiency, and two treatment target recommendations. The primary investigator then used the DIGEST (Hutcheson, et al., 2017) method to translate ratings of safety and efficiency into overall swallow severity.

RESULTS: Temporal and kinematic measures of PTT, PDT, and UESO, UESOD, and HLE were significantly impacted by reduced temporal resolution. Measures of safety, severity, and efficiency were not impacted by changes in frame rate.

CONCLUSION: Changes in temporal resolution had a significant effect on perception of temporal and kinematic measures but did not significantly affect ratings of safety and efficiency or treatment target selection. These findings indicate that, although perception of overall swallow severity was not greatly impacted, there was quantitative change as temporal resolution decreased. In clinical application, this means that diagnosis may not change as frame rate decreases, but perception of physiology is altered, which may guide decision-making. The direction of change was unpredictable, meaning that sensitivity and specificity are both affected as temporal resolution decreases.

Degree Name

Speech-Language Pathology

Level of Degree


Department Name

Speech and Hearing Sciences

First Committee Member (Chair)

Phyllis M. Palmer, Ph. D.

Second Committee Member

Aaron H. Padilla, M.S., CCC-SLP

Third Committee Member

Lori Nelson, M.S., CCC-SLP

Fourth Committee Member

Rick Arenas, Ph. D.




Dysphagia, Videofluroscopy, Radiation, Frame rate, Speech Pathology, New Mexico

Document Type