Laryngeal epithelial thickness: a comparison between optical coherence tomography and histology

Abstract

Objectives Optical coherence tomography, an imaging modality using near-infrared light, produces crosssectional tissue images with a lateral pixel resolution of 10 μm. However, normative data is first needed on epithelial thickness for lesion characterisation, and, to date, little exists. The purpose of our study is to measure normal laryngeal epithelial thickness by in vivo optical coherence tomography, and compare these values to those obtained from fixed ex-vivo laryngectomy specimens. Design and Setting Prospective at a single medical center in California, United States. Participants A total of 116 patients undergoing operative endoscopy. Main outcome measures Optical coherence tomography images of clinically normal laryngeal subsites were selected. Calibrated measurements of epithelial thickness at various laryngeal subsites were recorded. Measurements of epithelial thickness from corresponding areas were obtained using optical micrometry on histologically normal regions of 15 total laryngectomy specimens. Descriptive statistics were performed. Results Mean epithelial optical coherence tomography thicknesses were: true vocal cords (81 μm), false vocal cords (78 μm), subglottis (61 μm), aryepiglottic folds (111 μm), laryngeal epiglottis (116 μm) and lingual epiglottis (170 μm). Epithelial thicknesses in fixed tissues were: true vocal cords (103 μm), false vocal cords (79 μm), aryepiglottic folds (205 μm) subglottis (61 μm), laryngeal epiglottis (38 μm) and lingual epiglottis (130 μm). Conclusions Optical coherence tomography does not have the artifacts associated with conventional histologic techniques. The inevitable development of office-based optical coherence tomography devices will increase the precision of laryngeal measurements and contribute to the clinical application of this technology in diagnosing laryngeal disease.

Long-Range Optical Coherence Tomography of the Neonatal Upper Airway for Early Diagnosis of Intubation-related Subglottic Injury

“…The airway wall segmentation and measurement methods have been described in detail (31); similar software-based airway tissue measurement has been validated in previous OCT studies (12)(13)(14)(15)(16)(17). A single optimal data set from each LR-OCT case was selected based on signal-to-noise ratio, clarity of tissue contours, and soft tissue substructural resolution.…”

“…OCT evaluation and measurement of airway wall microanatomy has been validated with comparative computed ORIGINAL ARTICLE tomography (12) and histology (13)(14)(15)(16)(17). Previous reports describe OCT imaging of postintubation subglottic injury in ex vivo animal models (17,18) and intubated neonates (19).…”

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

“…6 Epithelial thicknesses can be measured in OCT scans for tumor staging. 6,7 These OCT studies with direct laryngoscopy were carried out with fiber-based OCT probes in contact mode influencing the accuracy of epithelial thickness measurements due to compression of the epithelium. 7 A different technical concept is to integrate an OCT system with a long working distance into a surgical microscope to work contactlessly.…”

“…6,7 These OCT studies with direct laryngoscopy were carried out with fiber-based OCT probes in contact mode influencing the accuracy of epithelial thickness measurements due to compression of the epithelium. 7 A different technical concept is to integrate an OCT system with a long working distance into a surgical microscope to work contactlessly. 8 The advantage of the concept is a convenient usage for the surgeon as the microscope and the OCT are using the same optics and the field of view is merged.…”

Endoscopic optical coherence tomography: technologies and clinical applications [Invited]

“…Imaging could be performed during surgical endoscopy by directing the probe to the larynx through a laryngoscope [35,185]. Such a forward scanning probe was used to establish a quantitative comparison between in vivo OCT measurements of epithelial thickness and light microscopy measurements on excised specimens [186]. To address a need for early cancer detection, a rigid OCT probe was developed that could be attached to the laryngoscope for office-based examination of patients without need of anesthesia [187].…”