title: Image-based measurement of post-swallow residue: the normalized residue ratio scale.
abstract: Post-swallow residue is considered a sign of swallowing impairment. Existing methods for capturing post-swallow residue (perceptual and quantitative) have inherent limitations. We employed several different perceptual and quantitative (ratio) methods for measuring post-swallow residue on the same 40 swallows and addressed the following questions: (1) Do perceptual and quantitative methods demonstrate good agreement? (2) What differences in precision are apparent by measurement method (one-dimensional, two-dimensional, and circumscribed area ratios)? (3) Do residue ratios agree strongly with residue area measures that are anatomically normalized? Based on the findings of this series of questions, a new method for capturing residue is proposed: the Normalized Residue Ratio Scale (NRRS). The NRRS is a continuous measurement that incorporates both the ratio of residue relative to the available pharyngeal space and the residue proportionate to the size of the individual. A demonstration of this method is presented to illustrate the added precision of the NRRS measurement in comparison to other approaches for measuring residue severity.
authors.affiliation: Department of Anatomy and Neurobiology, School of Medicine, Boston University, Boston, MA, USA.
authors.forename: William G
authors.initials: WG
authors.lastname: Pearson
authors.forename: Sonja M
authors.initials: SM
authors.lastname: Molfenter
authors.forename: Zachary M
authors.initials: ZM
authors.lastname: Smith
authors.forename: Catriona M
authors.initials: CM
authors.lastname: Steele
mesh_terms: D003679:Deglutition / Q000502:physiology*; D003680:Deglutition Disorders / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005471:Fluoroscopy; D006801:Humans; D008365:Manometry / Q000379:methods; D010614:Pharynx / Q000000981:diagnostic imaging* / Q000503:physiopathology