Pixel-Based Swallow Measurements: Correcting Nonsquare Pixels

Larsen D, Ikuma T, Neubig L, Kist A, Leonard R, McWhorter AJ, Kunduk M (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Journal of Speech Language and Hearing Research American Speech-Language-Hearing Association

Book Volume: 66

Pages Range: 565-572

Journal Issue: 2

DOI: 10.1044/2022_JSLHR-22-00306

Abstract

PURPOSE: This research note illustrates the effects of video data with nonsquare pixels on the pixel-based measures obtained from videofluoroscopic swallow studies (VFSS). METHOD: Six pixel-based distance and area measures were obtained from two different videoflouroscopic study units; both yielding videos with nonsquare pixels with different pixel aspect ratios (PARs). The swallowing measures were obtained from the original VFSS videos and from the videos after their pixels were squared. RESULTS: The results demonstrated significant multivariate effects both in video type (original vs. squared) and in the interaction between video type and sample (two video recordings of different patients, different PARs, and opposing tilt angles of the external reference). A wide range of variabilities was observed on the pixel-based measures between original and squared videos with the percent deviation ranging from 0.1% to 9.1% with the maximum effect size of 7.43. CONCLUSIONS: This research note demonstrates the effect of disregarding PAR to distance and area pixel-based parameters. In addition, we present a multilevel roadmap to prevent possible measurement errors that could occur. At the planning stage, the PAR of video source should be identified, and, at the analyses stage, video data should be prescaled prior to analysis with PAR-unaware software. No methodology in prior absolute or relative pixel-based studies reports adjustment to the PAR prior to measurements nor identify the PAR as a possible source of variation within the literature. Addressing PAR will improve the precision and stability of pixel-based VFSS findings and improve comparability within and across clinical and research settings. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.21957134.

Authors with CRIS profile

Luisa Neubig Juniorprofessur für Artificial Intelligence in Communication Disorders Andreas Kist Juniorprofessur für Artificial Intelligence in Communication Disorders

Involved external institutions

Louisiana State University US United States (USA) (US) UC Davis Medical Center US United States (USA) (US)

How to cite

APA:

Larsen, D., Ikuma, T., Neubig, L., Kist, A., Leonard, R., McWhorter, A.J., & Kunduk, M. (2023). Pixel-Based Swallow Measurements: Correcting Nonsquare Pixels. Journal of Speech Language and Hearing Research, 66(2), 565-572. https://doi.org/10.1044/2022_JSLHR-22-00306

MLA:

Larsen, Deirdre, et al. "Pixel-Based Swallow Measurements: Correcting Nonsquare Pixels." Journal of Speech Language and Hearing Research 66.2 (2023): 565-572.

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