Ryan P. Jackson

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 μm. 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.

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.

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 patients and physicians 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-enhanced microlaryngoscopy: preliminary report of a noncontact optical coherence tomography system integrated with a surgical microscope.

Objectives: Optical coherence tomography (OCT) is a new imaging modality that uses near-infrared light to produce cross-sectional images of tissue with a resolution approaching that of light microscopy. We have previously reported use of OCT imaging of the vocal folds (VFs) during direct laryngoscopy with a probe held in contact or near-contact with the VFs. This aim of this study was to develop and evaluate a novel OCT system integrated with a surgical microscope to allow hands-free OCT imaging of the VFs, which could be performed simultaneously with microscopic visualization. Methods: We performed a prospective evaluation of a new method of acquiring OCT images of the VFs. Results: An OCT system was successfully integrated with a surgical microscope to permit noncontact OCT imaging of the VFs of 10 patients. With this novel device we were able to identify VF epithelium and lamina propria; however, the resolution was reduced compared to that achieved with the standard contact or near-contact OCT. Conclusions: Optical coherence tomography is able to produce high-resolution images of vocal fold mucosa to a maximum depth of 1.6 mm. It may be used in the diagnosis of VF lesions, particularly early squamous cell carcinoma, in which OCT can show disruption of the basement membrane. Mounting the OCT device directly onto the operating microscope allows hands-free noncontact OCT imaging and simultaneous conventional microscopic visualization of the VFs. However, the lateral resolution of the OCT microscope system is 50 μm, in contrast to the conventional handheld probe system (10 μm). Although such images at this resolution are still useful clinically, improved resolution would enhance the systems performance, potentially enabling real-time OCT-guided microsurgery of the larynx.

In vivo optical coherence tomography of the nasal mucosa.

Background Optical coherence tomography (OCT) is an emerging imaging modality that uses light to produce in vivo high-resolution cross-sectional images (7 μm) of tissues to depths of up to 3 mm. OCT is analogous to ultrasound, but relies on interferometry and low-coherence optical sources to produce images of tissue structure at the histological level. Methods In this study, OCT was used to image the mucosa overlying structures in the nasal cavity to obtain information regarding normative in vivo tissue microstructure. An OCT system using a Michaelson interferometer and a 1.3-μm broadband light source was incorporated into a fiber-optic imaging device that was inserted into the nasal cavity. Cross-sectional tomographic images of the anterior and posterior nasal septum, turbinates, and vestibule were acquired in 44 patients in either the office or the operating room during surgical endoscopy. Results OCT images of the nasal mucosa identified the distinct boundaries between the epithelium, lamina propria, and underlying bone/cartilaginous tissue. Within the lamina propria, features consistent with glands, ducts, and blood vessels were clearly identified. In patients who underwent decongestant therapy, before and after images showed distinct morphological changes in the mucosa. The thickness of the epithelium was tabulated, as well. Conclusion This study establishes the potential of using OCT to produce high-resolution images of the nasal mucosa. As an in vivo tissue microstructural imaging modality, OCT may be valuable in studying the impact of allergic and infectious disease on the nasal mucosa and monitoring its response to pharmacologic therapy.

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.

Design of a low-cost, USB-compatible, otoscope image-capture system.

INTRODUCTION Despite abundant applications in telemedicine, education, and medical-legal documentation, physicians may hesitate to purchase currently available video otoscope systems because of their relatively high cost, low portability, and lack of integration with devices already present in the clinic. To this end, we produced a prototype lens system that fits a standard Welch-Allyn otoscope and captures images of the tympanic membrane (TM) with a charge coupled device (CCD) array from an USB 2.0-compatible web camera (Fig. 1). Image data are fed to a laptop or personal computer in real time, thus maximizing portability and eliminating the need to purchase stand-alone processing units. Large-scale production of this device would result in a unit that costs approximately

361 BENIGN AND MALIGNANT PROCESSES OF THE HUMAN LARYNX AS STUDIED BY OPTICAL COHERENCE TOMOGRAPHY

250 USD in comparison with non-PC compatible stand-alone devices that cost from

500 OPTICAL COHERENCE TOMOGRAPHY AND IMAGE ANALYSIS OF THE OROPHARYNX

1,000 to

Ho:YAG laser in reshaping tracheal cartilage: a pilot investigation using ex vivo porcine and rabbit cartilage

35,000 USD or more. In consideration of its portability, low cost, and ability to integrate readily with personal computers already in most clinics, this device has important applications in telemedicine, health care education, and in the medical-legal arena for documentation purposes. The diagnosis of middle ear disease can pose a challenge to health care practitioners; large geographic distances between patients and specialists may compound these challenges.1 Currently, there are three general options for capturing images of the TM: a microscope with camera attachment, “oto-endoscopy” systems, and video otoscope systems. The former two options are costly (