Exploring Reliable and Identifiable Quantitative Anatomical, Timing, and Displacement Measures in the VFS of Speech

Aim: Videofluroscopy studies of speech are a recognized assessment of velopharyngeal insufficiency (VPI). Yet, this method is subjective and has low inter-rater reliability. Quantitative measures of timing, distance, and area in videofluoroscopic studies of swallowing have been shown to be valid and reliable, but quantitative measures are not routinely used in videofluroscopy studies for VPI. This study explored the use of quantitative measures in patients with VPI in terms of feasibility and reliability. Methods: Forty patients of mixed etiology diagnosed with VPI through perceptual speech assessment underwent videofluroscopy. Anatomical landmarks and timing, distance, and area measurements were taken of the velopharyngeal port at rest and during speech tasks using specialized Swallowtail software. 50% of measures were double-blind rated to test inter-rater reliability. Raters reported on the time they took to complete each assessment and the challenges they had. Associations between measures were explored. Results: Ten timing, line, and area measures were developed based on 3 landmarks. Measures had moderate-substantial inter-rater reliability (intraclass coefficient: 0.69-0.91) except for time to lift (secs), which only achieved fair agreement (intraclass coefficient: 0.56). Measures demonstrated internal consistency (R > 0.60). Raters took, on average, 15 mins per patient and reported some challenges with image resolution, especially in timing measures where structures were blurred by movement. Conclusion: Quantitative measures are reliable and have the potential to add novel information regarding VPI to support multidisciplinary decision-making. Further research with larger patient cohorts is needed to clarify how quantitative measures can support tailored decisions about surgical and therapeutic interventions in order to maximize outcomes for individuals.