1. Articles in category: Otolaryngology

    289-312 of 354 « 1 2 ... 10 11 12 13 14 15 »
    1. Non-invasive optical interferometry for the assessment of biofilm growth in the middle ear

      Non-invasive optical interferometry for the assessment of biofilm growth in the middle ear
      Otitis media (OM) is the most common illness in children in the United States. Three-fourths of children under the age of three have OM at least once. Children with chronic OM, including OM with effusion and recurrent OM, will often have conductive hearing loss and communication difficulties, and need surgical treatment. Recent clinical studies provide evidence that almost all chronic OM cases are accompanied by a bacterial biofilm behind the tympanic membrane (eardrum) and within the middle ear. Biofilms are typically very thin, and cannot be recognized using a regular otoscope. Here we demonstrate how optical low coherence interferometry (LCI ...
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    2. In Vivo Simultaneous Morphological and Biochemical Optical Imaging of Oral Epithelial Cancer

      In Vivo Simultaneous Morphological and Biochemical Optical Imaging of Oral Epithelial Cancer

      Early detection of cancer is key to reducing morbidity and mortality. Morphological and chemical biomarkers presage the transition from normal to cancerous tissue. We have developed a noninvasive imaging system incorporating optical coherence tomography (OCT) and fluorescence lifetime imaging microscopy (FLIM) into a single optical system for the first time, in order to acquire both sets of biomarkers. OCT can provide morphological images of tissue with high resolution, while FLIM can provide biochemical tissue maps. Coregistered OCT volumes and FLIM images have been acquired simultaneously in an in vivo hamster cheek pouch model of oral cancer. The OCT images indicate ...

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    3. Phase-sensitive optical coherence tomography imaging of the tissue motion within the organ of Corti at a subnanometer scale: a preliminary study

      Phase-sensitive optical coherence tomography imaging of the tissue motion within the organ of Corti at a subnanometer scale: a preliminary study
      Hearing loss can mean severe impairment to the quality of life. However, the biomechanical mechanisms of how the hearing organ, i.e., the organ of Corti (OC), responds to sound are still elusive, largely because there is currently no means available to image the 3-D motion characteristics of the OC. We present a novel use of the phase-sensitive spectral domain optical coherence tomography (PSOCT) to characterize the motion of cellular compartments within the OC at a subnanometer scale. The PSOCT system operates at 1310 nm with a spatial resolution of ~16 µm and an imaging speed of 47,000 A-lines ...
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    4. Optical coherence tomography allows for the reliable identification of laryngeal epithelial dysplasia and for precise biopsy: A clinicopathological study of 61 patients undergoing microlaryngoscopy

      Optical coherence tomography allows for the reliable identification of laryngeal epithelial dysplasia and for precise biopsy: A clinicopathological study of 61 patients undergoing microlaryngoscopy
      Objectives/Hypothesis: A newly developed microscope-based spectral-domain optical coherence tomography (SD-OCT) device and an endoscope-based time-domain OCT (TD-OCT) were used to assess the inter-rater reliability, sensitivity, specificity, and accuracy of benign and dysplastic laryngeal epithelial lesions. Study Design: Prospective study. Methods: OCT during microlaryngoscopy was done on 35 patients with an endoscope-based TD-OCT, and on 26 patients by an SD-OCT system integrated into an operating microscope. Biopsies were taken from microscopically suspicious lesions allowing comparative study of OCT images and histology. Results: Thickness of the epithelium was seen to be the main criterion for degree of dysplasia. The inter-rater reliability ...
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    5. Airway surface liquid depth imaged by surface laser reflectance microscopy

      Airway surface liquid depth imaged by surface laser reflectance microscopy
      The thin layer of liquid at the surface of airway epithelium, the airway surface liquid (ASL), is important in normal airway physiology and in the pathophysiology of cystic fibrosis. At present, the best method to measure ASL depth involves scanning confocal microscopy after staining with an aqueous-phase fluorescent dye. We describe here a simple, noninvasive imaging method to measure ASL depth by reflectance imaging of an epithelial mucosa in which the surface is illuminated at a 45-degree angle by an elongated 13-µm wide rectangular beam produced by a 670-nm micro-focus laser. The principle of the method is that air–liquid ...
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      Mentions: UCSF
    6. The effect of mandibular advancement on upper airway structure in obstructive sleep apnoea

      The effect of mandibular advancement on upper airway structure in obstructive sleep apnoea

      Background The mechanisms by which mandibular advancement splints (MAS) improve obstructive sleep apnoea (OSA) are not well understood. This study aimed to evaluate the mechanism of action of MAS by assessing their effect on upper airway structure in patients with OSA. Methods Patients were recruited from a sleep disorders clinic for treatment with a custom-made MAS. MRI of the upper airway was performed during wakefulness in the supine position, with and without the MAS. Results Sixty-nine patients with OSA were recruited. Treatment with the MAS reduced the apnoea–hypopnoea index (AHI) from 27.0±14.7 events/h to 12 ...

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    7. Multimodal imaging guidance for laser ablation in tracheal stenosis

      Multimodal imaging guidance for laser ablation in tracheal stenosis
      Objective/Hypothesis: Laser-induced damage of tracheal wall microstructures might contribute to recurrence after bronchoscopic treatment of tracheal strictures. The purpose of this study was to demonstrate how multimodal imaging using white light bronchoscopy (WLB), endobronchial ultrasound (EBUS), and optical coherence tomography (OCT) might identify in vivo airway wall changes before and resulting from Nd:YAG laser ablation and dilation of tracheal stenosis. Study Design: Case study. Methods: Commercially available WLB, high frequency EBUS using a 20-MHz radial probe and time-domain, frontal imaging OCT systems were used to characterize the extent, morphology, and airway wall microstructures at the area of hypertrophic ...
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    8. Volumetric in vivo imaging of intracochlear microstructures in mice by high-speed spectral domain optical coherence tomography

      Volumetric in vivo imaging of intracochlear microstructures in mice by high-speed spectral domain optical coherence tomography
      There is considerable interest in developing new methods for in vivo imaging of the complex anatomy of the mammalian cochlea for clinical as well as fundamental studies. In this study, we explored, the feasibility of spectral domain optical coherence tomography (SD-OCT) for 3-D in vivo imaging of the cochlea in mice. The SD-OCT system employed in this study used a broadband light source centered at 1300 nm, and the imaging speed of the system was 47,000 A-scans per second using the InGaAs camera. The system was capable of providing fully processed, high-resolution B-scan images [512 (axial)×128 (lateral) pixels ...
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    9. In vivo 3D human vocal fold imaging with polarization sensitive optical coherence tomography and a MEMS scanning catheter

      In vivo 3D human vocal fold imaging with polarization sensitive optical coherence tomography and a MEMS scanning catheter
      We present in-vivo 3D human vocal fold images with polarization sensitive optical coherence tomography (PS-OCT). Characterizing the extent and location of vocal fold lesions provides useful information in guiding surgeons during phonomicrosurgery. Previous studies showed that PS-OCT imaging can distinguish vocal fold lesions from normal tissue, but these studies were limited to 2D cross-sectional imaging and were susceptible to sampling error. In-vivo 3D endoscopic imaging was performed by using a recently developed 2-axis MEMS scanning catheter and a spectral domain OCT (SD-OCT), running at 18.5 frames/s. Imaging was performed in the operating room with patients under general anesthesia ...
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    10. Dynamic imaging of vocal fold oscillation with four-dimensional optical coherence tomography

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

      Optical coherence tomography (OCT) can provide high-resolution ([sim]10-15 [mu]m/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.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.Larynges were imaged during ...

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    11. State of the art laryngeal imaging: research and clinical implications

      State of the art laryngeal imaging: research and clinical implications
      Purpose of review: This study provides a review of the latest advances in videostroboscopy, videokymography and high-speed videoendoscopy, and outlines the development of new laryngeal imaging modalities based on optical coherence tomography, laser-depth kymography, and magnetic resonance imaging (MRI), published in the past 2 years. Recent findings: Videostroboscopy and videokymography: Image quality has improved and several image processing and measurement techniques have been published. High-speed videoendoscopy: Significant progress has been made through increased sensitivity and frame rates of the cameras, and the development of facilitative playbacks, phonovibrography and several image segmentation and measurement methods. Clinical evidence was presented through applications ...
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    12. Optical Coherence Tomography of the Larynx Using the Niris System

      Optical Coherence Tomography of the Larynx Using the Niris System
      OBJECTIVES:To present our experience using the first commercially available optical coherence tomography (OCT) device for use in the head, neck, and upper aerodigestive tract and to determine the feasibility and efficacy of this system in comparison with our previous experience using other research OCT systems.METHODS:Using the Niris OCT imaging system (Imalux, Cleveland, OH), we obtained OCT images of benign and premalignant laryngeal disease in 33 patients undergoing surgical head and neck endoscopy. This imaging system has a spatial depth resolution of 10 to 20 μm and a depth scanning range of 2.2 mm, obtaining images of ...
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    13. An optical coherence tomography study for imaging the round window niche and the promontorium tympani

      An optical coherence tomography study for imaging the round window niche and the promontorium tympani
      An optical coherence tomography study for imaging the round window niche and the promontorium tympani Tympanosclerosis may involve the tympanic membrane, the ossicles, and the oval and round window niche, respectively. The surgical treatment of the obliterated oval window niche is most challenging. Beside stapesplasty, vibroplasty coupling the floating mass transducer (FMT) onto the round window niche and into a new, so-called third window is indicated. In the latter situation, drilling a hole into the promontorium is necessary to couple the FMT close to the membranous endosteum. Damage of the membranous inner ear must be avoided. The question was whether ...
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    14. Measurement of epithelial thickness within the oral cavity using optical coherence tomography (OCT)

      Measurement of epithelial thickness within the oral cavity using optical coherence tomography (OCT)
      Optical coherence tomography (OCT) is a promising method in the early diagnosis of oral cavity cancer. The objective of the present study is to determine normal values of epithelial thickness in the oral cavity, as no such data are to be found in the literature. In healthy test persons, epithelial thickness of the oral mucosa was determined with the help of OCT separately for each side at nine different locations. Special attention was directed to those sites having the highest incidence for the development of dysplasias and carcinomas. Depending on the location within the oral cavity, the epithelium demonstrated a ...
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    15. Emerging applications for OCT in the head and neck

      Emerging applications for OCT in the head and neck
      Objectives: To describe the current and promising new applications of Optical Coherence Tomography (OCT) as a helpful tool when imaging the different sites in the head and neck. We used the OCT Niris system, which is the first commercially available OCT device for applications outside the field of ophthalmology. Methods: OCT images were obtained of normal, benign, premalignant and malignant lesions in different areas of the head and neck. The OCT imaging system has a tissue penetration depth of approximately 1-2mm, a scanning range of 2mm and a spatial depth resolution of approximately 10-20µm. Imaging was performed using a flexible ...
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    16. Overcoming barriers in topical administration of gold nanoparticles for optical coherence tomography using multimodal delivery

      Overcoming barriers in topical administration of gold nanoparticles for optical coherence tomography using multimodal delivery
      Optical coherence tomography (OCT) is a non-invasive and promising imaging modality with high resolution that is an order of magnitude higher than current diagnostic techniques. However, its use in detecting early-stage cancer is limited due to insufficient contrast level in biological tissue, which can be enhanced by harnessing contrast agents [e.g., gold nanoparticles (Au NPs)]. Enhanced penetration by creating micropassages and distribution by ultrasonic force (multimodal topical delivery) was proven to overcome two major barriers (stratum corneum and epithelial barriers) in topically administering Au NPs using an in vivo oral dysplasia hamster model (overall 150% enhanced OCT contrast). Expanded ...
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    17. Optical and molecular techniques to identify tumor margins within the larynx

      Optical and molecular techniques to identify tumor margins within the larynx
      Failure to remove tumor cells from the larynx significantly increases the risk of local recurrence following surgical excision. Healthy tissue must be preserved to optimize long-term vocal and swallowing function. It is essential to accurately distinguish between healthy mucosa, dysplasia, and invasive carcinoma. Optical and molecular examining technologies have been developed to improve tumor margin identification in vivo. We aimed to review the efficacy of these technologies. Published articles were identified using MEDLINE, EMBASE, and Cochrane central register of controlled trials (CENTRAL). Randomized clinical trials are required to establish the benefit to patients and cost to the health service of ...
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    18. Cervical Soft Tissue Motion Measurement by Optical Coherence Tomography

      To design a semi-automatic laser scalpel for tissue resection in the area of neck masses it was necessary to examine the biomechanic behavour of these tissues. The aim was to identify if and to what extent (amplitude and velocity) the tissues shift due to respiration and circulation. This is important since these movements have to be followed by the laser scalpel. At defined points on the neck surface onedimensional (1-D) time related Optical Coherence Tomography OCT measurements were recorded. Tissue shifting in the direction of the OCT-sightaxis was quantified. The preliminary results of these basic experiments shown here will be ...
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    19. Detecting precancerous lesions in the hamster cheek pouch using spectroscopic white-light optical coherence tomography to assess nuclear morphology via spectral oscillations

      We have developed a novel dual-window approach for spectroscopic optical coherence tomography (OCT) measurements and applied it to probe nuclear morphology in tissue samples drawn from the hamster cheek pouch carcinogenesis model. The dual-window approach enables high spectral and depth resolution simultaneously, allowing detection of spectral oscillations, which we isolate to determine the structure of cell nuclei in the basal layer of the epithelium. The measurements were executed with our parallel frequency domain OCT system, which uses light from a thermal source, providing high bandwidth and access to the visible portion of the spectrum. The structural measurements show a highly ...
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    20. Morphologic Classification of Reinke's Edema through Optical Coherence Tomography

      OBJECTIVE: Several classification systems for Reinke's edema have been proposed in the past, which are somewhat less than morphologically ideal. The objective of the present study is to evaluate the ability of optical coherence tomography (OCT) to attain a reproducible graduation of Reinke's edema. MATERIAL AND METHODS: In a prospective study, 30 consecutive patients underwent endolaryngeal, microsurgical resection of their Reinke's edema. Graduation was performed through OCT based on morphologic criteria, where each result was compared with that of other classification systems. RESULTS: In Reinke's edema grade I according to Glanz, a feathered pattern is found ...
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    21. Office-based dynamic imaging of vocal cords in awake patients with swept-source optical coherence tomography

      Optical coherence tomography (OCT) is an evolving noninvasive imaging modality that has been used to image the human larynx during surgical endoscopy. The design of a long gradient index (GRIN) lens–based probe capable of capturing images of the human larynx by use of swept-source OCT during a typical office-based laryngoscopy examination is presented. In vivo OCT imaging of the human larynx is demonstrated with a rate of 40 frames per second. Dynamic vibration of the vocal folds is recorded to provide not only high-resolution cross-sectional tissue structures but also vibration parameters, such as the vibration frequency and magnitude of ...
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    22. Feature Of The Week 11/15/09: A Comparison between Optical Coherence Tomography and Histology of Laryngeal Epithelial Thickness

      Feature Of The Week 11/15/09: A Comparison between Optical Coherence Tomography and Histology of Laryngeal Epithelial Thickness
      Feature Of The Week 11/15/09: While applications of optical coherence tomography in ophthalmology and cardiology have very successfully transitioned from the research world to the commercial world many other fields have lagged behind. One such area is the field of Otolaryngology. While much of the technology developed in both the academic and commercial worlds is directly applicable to applications in otolaryngology there remain some unique features such as probe design and a need for additional clinical data to determine where OCT will be most beneficial. Numerous researchers around the world are working in this field. Researchers from the ...
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    23. Laryngeal epithelial thickness: a comparison between optical coherence tomography and histology

      Objectives: Optical coherence tomography, an imaging modality using near-infrared light, produces cross-sectional 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 ...
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    24. Feature Of The Week 9/13/09: In vivo imaging of human labial glands using advanced Optical Coherence Tomography

      Feature Of The Week 9/13/09: In vivo imaging of human labial glands using advanced Optical Coherence Tomography
      Feature Of The Week 9/13/09: Optical coherence tomography (OCT) has emerged as a high-resolution noninvasive clinical imaging application. Conventionally, minor salivary gland biopsy has been considered to be the cornerstone of the diagnosis of Sjögren syndrome. However, a minor salivary gland biopsy is an invasive examination that may cause inconvenience and a risk of complications to the patient. The purpose of this study was to show OCT images of human labial glands obtained using a swept-source (SS) OCT system. Labial gland OCT imaging was carried out using our new SS-OCT system for 5 healthy volunteers Using a hand-held ...
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