Measurement of Hyoid and Laryngeal Displacement in Video Fluoroscopic Swallowing Studies: Variability, Reliability, and Measurement Error

Abstract

Video fluoroscopy is commonly used in the study of swallowing kinematics. However, various procedures used in linear measurements obtained from video fluoroscopy may contribute to increased variability or measurement error. This study evaluated the influence of calibration referent and image rotation on measurement variability for hyoid and laryngeal displacement during swallowing. Inter- and intrarater reliabilities were also estimated for hyoid and laryngeal displacement measurements across conditions. The use of different calibration referents did not contribute significantly to variability in measures of hyoid and laryngeal displacement but image rotation affected horizontal measures for both structures. Inter- and intrarater reliabilities were high. Using the 95% confidence interval as the error index, measurement error was estimated to range from 2.48 to 3.06 mm. These results address procedural decisions for measuring hyoid and laryngeal displacement in video fluoroscopic swallowing studies.

Use of an Anatomical Scalar to Control for Sex-Based Size Differences in Measures of Hyoid Excursion During Swallowing

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Videofluoroscopic Investigation of Body Position on Articulatory Positioning

“…Sia, Carvajal, Carnaby-Mann, and Crary (2012) pointed out that "radial distortion causes an image to be increasingly stretched toward the periphery" (p. 192) of the field of view. Although videofluoroscopy allows visualization of articulatory gestures and swallowing function, the spatial resolution offered by the technique may not be sufficient to detect the smallest changes in articulatory positioning induced by different body positions.…”

The Blind Scientists and the Elephant of Swallowing: A Review of Instrumental Perspectives on Swallowing Physiology

“…If a patient is not seated at precisely 90 degrees to the camera, or is tilting their head or shoulders, this can result in image distortion and shadows that make it difficult to clearly define structural boundaries (Sia et al . ). One situation that poses a clear challenge with respect to spatial resolution is the measurement of residue severity.…”