title: In vivo optical coherence tomography of the human larynx: normative and benign pathology in 82 patients.
abstract: OBJECTIVE
  Optical coherence tomography (OCT) is an emerging imaging modality that combines low-coherence light with interferometry to produce cross-sectional images of tissue with resolution about 10 mum. Patients undergoing surgical head and neck endoscopy were examined using a fiberoptic OCT imaging probe to study and characterize microstructural anatomy and features of the larynx and benign laryngeal pathology in vivo.
  
  
  METHODS
  Prospective clinical trial.
  
  
  METHODS
  OCT imaging of the larynx was performed in 82 of 115 patients who underwent surgical endoscopy for various head and neck pathologies. The OCT device employs a 1.3 microm broadband light source (FWHM, 80 nm). The frame rate is 1 Hz. Imaging was performed using a handheld probe placed in near contact with the target site. The maximum axial and lateral dimensions for the region of interest imaged were 2.5 mm x 6 mm, with resolutions of 10 microm. Simultaneously, conventional endoscopic images were obtained to provide anatomic correlation with OCT images and histology. Optical micrometry was performed to measure the epithelium thickness.
  
  
  RESULTS
  Systematic OCT imaging of laryngeal structures and subsites provided information on the thickness of the epithelium, integrity of the basement membrane, and structure of the lamina propria. Microstructural features identified included glands, ducts, blood vessels, fluid collection/edema, and the transitions between pseudostratified columnar and stratified squamous epithelium. The mean epithelial thickness of laryngeal subsites was calculated: true vocal cord (129 microm), false vocal cords (124 microm), aryepiglottic fold (177 microm), subglottis (98 microm), and epiglottis (185 microm). True vocal cord pathology imaged included Reinke's edema, papillomatosis, polyps, mucous cysts, and granulation tissue. Subglottic imaging identified boundaries between epithelium, lamina propria, and cartilage. The OCT images compared favorably with conventional histopathology.
  
  
  CONCLUSIONS
  OCT has the unique ability to image laryngeal tissue microstructure and can detail microanatomic changes in benign, premalignant, and malignant laryngeal pathologies. OCT holds the potential to guide surgical biopsies, direct therapy, and monitor disease, particularly when office-based systems are developed. This is a promising imaging modality to study the larynx.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California Irvine, Orange, California, USA. bjwong@uci.edu
authors.forename: Brian J F
authors.initials: BJ
authors.lastname: Wong
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Jackson
authors.forename: Shuguang
authors.initials: S
authors.lastname: Guo
authors.forename: James M
authors.initials: JM
authors.lastname: Ridgway
authors.forename: Usama
authors.initials: U
authors.lastname: Mahmood
authors.forename: Jianping
authors.initials: J
authors.lastname: Su
authors.forename: Terry Y
authors.initials: TY
authors.lastname: Shibuya
authors.forename: Roger L
authors.initials: RL
authors.lastname: Crumley
authors.forename: Mai
authors.initials: M
authors.lastname: Gu
authors.forename: William B
authors.initials: WB
authors.lastname: Armstrong
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Chen
mesh_terms: D001706:Biopsy; D003937:Diagnosis, Differential; D004724:Endoscopy; D005336:Fiber Optic Technology; D006258:Head and Neck Neoplasms / Q000601:surgery; D006801:Humans; D007432:Intraoperative Period; D007818:Laryngeal Diseases / Q000473:pathology*; D007830:Larynx / Q000648:ultrastructure*; D011446:Prospective Studies; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence / Q000379:methods*