Dynamic imaging of vocal fold oscillation with four‐dimensional optical coherence tomography

Abstract

Objectives/Hypothesis Optical coherence tomography (OCT) can provide high-resolution (~10–15 μm/pixel) images of vocal fold microanatomy, as demonstrated previously. We explored physiologically triggered Fourier-domain OCT for imaging vocal folds during phonation. The goal is to visualize dynamic histological cross sections and four-dimensional data sets where multiple planes are displayed in synchronized motion. If feasible, this approach could be a useful research tool and spur development of new clinical instrumentation. Study Design A Fourier-domain, triggered OCT system was created and tested in experiments on excised calf larynges to obtain preliminary observations and characterize important factors affecting image quality. Methods Larynges were imaged during phonation driven by warm, humidified air. A subglottal pressure signal was used to synchronize the OCT system with the phonatory cycle. Image sequences were recorded as functions of anatomical location or sub-glottal pressure. Implant materials were also imaged during vibration, both in isolation and after injection into a vocal fold. Results Oscillations of epithelium and lamina propria were observed, and parameters such as shape, amplitude, and velocity of the vocal fold mucosal waves were found to be measurable. Ripples of mucosal wave as small as 100 μm in vertical height were clearly visible. Internal strain was also observed in normal and implanted vocal folds. Conclusions Four-dimensional OCT of the vocal fold may help to more directly relate biomechanics to anatomy and disease. It may also be useful for assaying the functional rheology of implants in the context of real tissue. With further development, this technology has potential for clinical endoscopic application.

Automated working distance adjustment enables optical coherence tomography of the human larynx in awake patients

“…The system we presented here utilized B-scans either in line or perpendicular to the glottis, therefore, the movement of the mucosal wave was imaged which has been so far only demonstrated in an ex vivo model. 10 The mucosal wave forms its highest amplitude at the medial margin of the vocal fold. The oscillation was damped towards the lateral parts of the vocal cord which was clearly visualized in OCT video sequences.…”

“…6 For functional aspects videostroboscopy (pseudo real time) and high-speed imaging (real time and lowimage resolution) are well established tools in clinical practice that already give information on the mucosal wave formation and lateral (horizontal) wave motion. 10 The feasibility of OCT measurement of physical parameters like vibration amplitude and frequency has been demonstrated using excised larynges, which were actuated by air blow to simulate phonation. 10 The image acquisition was synchronized to a measured subglottal pressure signal in order to trigger a record of a full oscillatory cycle as an M-scan before moving to the next lateral position.…”

“…10 The feasibility of OCT measurement of physical parameters like vibration amplitude and frequency has been demonstrated using excised larynges, which were actuated by air blow to simulate phonation. 10 The image acquisition was synchronized to a measured subglottal pressure signal in order to trigger a record of a full oscillatory cycle as an M-scan before moving to the next lateral position. 10 Analysis of cross-sectional images which are sequentially taken at the same position allowed for motion tracking within the layered structure of the vocal folds.…”

“…10 The image acquisition was synchronized to a measured subglottal pressure signal in order to trigger a record of a full oscillatory cycle as an M-scan before moving to the next lateral position. 10 Analysis of cross-sectional images which are sequentially taken at the same position allowed for motion tracking within the layered structure of the vocal folds. Thus the local velocity distribution is reconstructed, 11 which can improve both clinical diagnosis as well as physiological studies of the vibration mechanism.…”

Optical coherence tomography for biofilm detection in chronic rhinosinusitis with nasal polyposis

“…Furthermore, OCT has been reported to be a helpful method in diVerent laryngological applications, especially in the evaluation of laryngeal cancer and its precursor lesions [24,25]. In the phoniatric practice, OCT has been found to be a highly sophisticated method in the assessment of shape, amplitude, and velocity of vocal fold mucosal waves providing biomechanical characteristics of vocal folds with various laryngeal pathologies [26,27]. Finally, OCT has been reported to be a robust method in the prediction of the severity of postintubation upper airway stenosis in children by the assessment of submucosal Wbrosis [28,29].…”