In vivo optical coherence tomography of the human oral cavity and oropharynx.

Optical coherence tomography (OCT) is an evolving imaging modality that combines interferometry with low-coherence light to produce high-resolution tissue imaging. Cross-sectional in vivo images were obtained using an OCT device consisting of a Michelson interferometer, 1.3-microm broadband light source, and a handheld fiberoptic imaging probe. Image pixel resolution approached 10 microm. The mucosa of the oral cavity and oropharynx were examined in 41 patients during operative endoscopy. Optical coherence tomographic imaging was combined with endoscopic photography for gross and histologic image correlation. Optical coherence tomographic images of the oral cavity and oropharynx provided microanatomical information on the epithelium, basement membrane (BM), and supporting lamina propria (LP) of the mucosa. Normal microstructures identified in these tissues included an overlying keratin layer, papillae, ducts, glands, and blood vessels. Regions of pathologic features studied included mature scar, granulation tissue, mucous cysts, leukoplakia, and invasive cancer. Optical coherence tomographic imaging showed distinct zones of normal, altered, and ablated tissue microstructures for each pathologic process studied. Abnormal findings were directly compared with regions of normal tissue or conventional histopathologic features when tissue for analysis was available. This study provides a composite series of in vivo OCT images of the oral cavity and oropharynx in a variety of normal regions and pathologic states as well as outline future applications of OCT technology.

Office-based optical coherence tomographic imaging of human vocal cords.

Optical coherence tomography (OCT) is an evolving noninvasive imaging modality and has been used to image the larynx during surgical endoscopy. The design of an OCT sampling device capable of capturing images of the human larynx during a typical office based laryngoscopy examination is discussed. Both patient's and physician's movements were addressed. In vivo OCT imaging of the human larynx is demonstrated. Though the long focal length limits the lateral resolution of the image, the basement membrane can still be readily distinguished. Office-based OCT has the potential to guide surgical biopsies, direct therapy, and monitor disease. This is a promising imaging modality to study the larynx.

Optical coherence tomography of laryngeal cancer.

OBJECTIVES: Optical coherence tomography (OCT) is a high-resolution optical imaging technique that produces cross-sectional images of living tissues using light in a manner similar to ultrasound. This prospective study evaluated the ability of OCT to identify the characteristics of laryngeal cancer and measure changes in the basement membrane, tissue microstructure, and the transition zone at the edge of tumors. MATERIALS AND METHODS: One hundred thirty-three patients underwent OCT examination during surgical endoscopy of the head and neck. Twenty-two patients with laryngeal cancer or a history of laryngeal cancer were imaged with a fiberoptic OCT system. Tumor and adjacent transition zones were imaged along with uninvolved subsites. OCT images were correlated with histopathology. RESULTS: Twenty-six OCT examinations were performed in 22 patients. Basement membrane disruption was seen in 18 subjects, all of whom had histology showing classic features of cancer. A transition zone to uninvolved epithelium at the tumor periphery was also often observed. In six studies, benign or premalignant processes were histologically confirmed. In three thin, superficial lesions, an intact basement membrane was observed. The basement membrane could not be identified in three other bulky exophytic, premalignant lesions, primarily because of increased superficial signal backscattering observed in pathologic tissues. CONCLUSIONS: OCT clearly identifies basement membrane violation from laryngeal cancer and can identify transition zones at the cancer margin. In bulky exophytic lesions, OCT signal may not penetrate deeply enough to show the basement membrane, but for many suspicious lesions that require exclusion of cancer, OCT shows potential for assisting in diagnostic assessment.

In vivo optical coherence tomography of the human larynx: normative and benign pathology in 82 patients.

OBJECTIVES: 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. STUDY DESIGN: Prospective clinical trial. MATERIALS AND 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. CONCLUSION: 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.

A novel laryngoscope instrument stabilizer for operative microlaryngoscopy.

OBJECTIVE: To evaluate and optimize the design of a removable and inexpensive internal stabilization device to reduce the effect of intention tremor during laryngeal microsurgery. STUDY DESIGN AND SETTING: In this laboratory investigation, stabilizers were designed and constructed to allow a nonobstructing view of the surgical field, permit simple insertion and removal, and accommodate microsurgical instruments. Prototype stabilizers were tested by using a Dedo laryngoscope, a measurement grid, and video recording equipment, which recorded instrument tremor within the magnified operative field for later analysis. Physicians also rated instrument stability, mobility, visualization, and ease of use on a survey form. RESULTS: Instrument tremor was reduced approximately 90%, with little obstruction of view of the surgical field. Instrument range of motion was reduced but improved rapidly as the stabilizer bar was moved further from the tip of the laryngoscope. CONCLUSIONS: Use of a stabilization device in the laryngoscope lumen reduces instrument tremor and has the potential to improve surgical performance during laryngeal microsurgery. EBM RATING: B-3.