Vocal fold length measurements with computed tomography

Abstract

Computed tomography (CT) was used for vocal fold length measurements in a pilot study on five normal subjects. Repeated phonations at a stable pitch showed a maximal length variation of 3% between measurements. An increase in voice intensity for fixed phonation pitch resulted in a minor shortening of the vocal fold length. This shortening was, however, within the measurement error. The length of the membranous part of the vocal folds determined from CT examination appears to be a suitable distance for calibrations if absolute glottal area or lengths are to be measured from video recorded laryngeal examinations with flexible or rigid endoscopes. The method requires that the subject or patient is able to produce repeated phonations matching a given pitch.