Laryngeal Videostroboscopic Images PDF Download

Background: Laryngeal imaging plays a vital role in the diagnosis and ongoing treatment of patients with vocal-fold mass lesions. Visual information regarding vocal fold vibratory function informs surgical decision making and maps the resultant change in vibratory function after surgery. Currently the clinical gold standard for laryngeal imaging is videostroboscopy; however, well-documented technological limitations inherent to videostroboscopy's sampling methodology reduce the effectiveness of this imaging technique when patients present with moderate or severe dysphonia. High-speed videoendoscopy (HSV) overcomes these technological limitations, and may therefore be able to facilitate more accurate and reliable measures of voice outcomes as a result of phonomicrosurgery. Additionally, HSV can provide multiple playback techniques, including simulated stroboscopy (SS) and digital kymography (DKG) which has the potential to maximize the effectiveness of HSV in a clinical setting. The motivation for this study is the need to establish the efficacy of HSV as a clinical tool which can allow clinicians to accurately and reliably measure change in vibratory function before and after intervention. Objective: The goal of this study is to compare videostroboscopy and two HSV-derived facilitative playback techniques in terms of their ability to provide reliable visual-perceptual ratings of vocal-fold function, which accurately measure change in vibratory function following surgical removal of vocal-fold mass lesions. Methods: Videostroboscopy and HSV recordings were collected from 28 patients with vocal fold mass lesions before and after phonomicrosurgery and 17 normal controls. DKG line scans an SS samples were derived from the original high-speed recordings resulting in three experimental datasets: traditional videostroboscopy, SS, and HSV dynamically linked to DKG (HSV+DKG). Two speech-pathologists with expertise in voice rated clinically-salient vocal fold vibratory features for each dataset. Ratings were compared across imaging techniques and to intraoperative measures of lesion size to determine the accuracy and reliability of each technique to measure change in vibratory function before and after phonomicrosurgery. Results: Raters were able to rate approximately 97% of the HSV+DKG data, 95% of the SS data, and 86% of the videostroboscopy data. Inter-rater reliability was poor for left-right phase asymmetry using videostroboscopy and SS, but moderate using HSV+DKG. Rater reliability was moderate for amplitude and vocal fold edge using all three imaging techniques and moderate to near-perfect for mucosal wave using HSV+DKG and SS. Change in function measured using both videostroboscopy and HSV+DKG showed mild-moderate correlations to the total area of the lesion as calculated from calibrated intra-operative images. Comparison of group means suggest that videostroboscopy can be used for measuring change in vocal fold edge following surgery; SS can be used for measuring change in amplitude, mucosal wave, and vocal fold; and HSV+DKG can be used for measuring change in amplitude, vocal fold edge, and left-right phase asymmetry. Strong to very strong correlations of ratings from HSV+DKG and SS indicate that SS produces a valid representation of the true intra-cycle vibratory as captured using HSV+DKG. Conclusions: HSV+DKG and SS are more accurate and reliable imaging techniques for measuring change in vibratory function following phonomicrosurgery than traditional videostroboscopy.