1. Articles from Harvey O. Coxson

    1-12 of 12
    1. Sex Differences in Airway Remodeling in a Mouse Model of Chronic Obstructive Pulmonary Disease

      Sex Differences in Airway Remodeling in a Mouse Model of Chronic Obstructive Pulmonary Disease

      Rationale: Adjusting for the amount of smoking, women have a 50% increased risk of COPD compared with men. It is not known what the anatomic basis/mechanism(s) of these sex-related differences in COPD might be. Objective: To characterize the impact of female sex hormones on chronic cigarette smoke-induced airway remodeling and emphysema in a mouse model of COPD. Methods: Airway remodeling and emphysema were determined morphometrically in male, female, and ovariectomized mice exposed to 6 months of cigarette smoke. Antioxidant- and transforming growth factor (TGFβ)-related genes were profiled in airway tissues. The selective estrogen receptor modulator, tamoxifen, was ...

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    2. Reproducibility of optical coherence tomography airway imaging

      Reproducibility of optical coherence tomography airway imaging

      Optical coherence tomography (OCT) is a promising imaging technique to evaluate small airway remodeling. However, the short-term insertion-reinsertion reproducibility of OCT for evaluating the same bronchial pathway has yet to be established. We evaluated 74 OCT data sets from 38 current or former smokers twice within a single imaging session. Although the overall insertion-reinsertion airway wall thickness (WT) measurement coefficient of variation (CV) was moderate at 12%, much of the variability between repeat imaging was attributed to the observer; CV for repeated measurements of the same airway (intra-observer CV) was 9%. Therefore, reproducibility may be improved by introduction of automated ...

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    3. Bronchial thermoplasty in asthma: 2-year follow-up using optical coherence tomography

      Bronchial thermoplasty in asthma: 2-year follow-up using optical coherence tomography

      Bronchial thermoplasty (BT) is a novel, nonpharmacological procedure for treatment of severe asthma. Recently, the Asthma Intervention Research 2 clinical trial demonstrated asthmatics had fewer hospitalisations following BT, which persisted 5 years after therapy [1]. However, it is well recognised that asthma is a heterogeneous disease with distinct asthma phenotypes and, not surprisingly, not all asthmatics in that trial benefited from BT [2].

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    4. Validation of Airway Wall Measurements by Optical Coherence Tomography in Porcine Airways

      Validation of Airway Wall Measurements by Optical Coherence Tomography in Porcine Airways

      Examining and quantifying changes in airway morphology is critical for studying longitudinal pathogenesis and interventions in diseases such as chronic obstructive pulmonary disease and asthma. Here we present fiber-optic optical coherence tomography (OCT) as a nondestructive technique to precisely and accurately measure the 2-dimensional cross-sectional areas of airway wall substructure divided into the mucosa (WA muc ), submucosa (WA sub ), cartilage (WA cart ), and the airway total wall area (WAt). Porcine lung airway specimens were dissected from freshly resected lung lobes (N = 10). Three-dimensional OCT imaging using a fiber-optic rotary-pullback probe was performed immediately on airways greater than 0.9 mm ...

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    5. Automated segmentation of porcine airway wall layers using optical coherence tomography: comparison with manual segmentation and histology

      Automated segmentation of porcine airway wall layers using optical coherence tomography: comparison with manual segmentation and histology

      The objective was to develop an automated optical coherence tomography (OCT) segmentation method. We evaluated three ex-vivo porcine airway specimens; six non-sequential OCT images were selected from each airway specimen. Histology was also performed for each airway and histology images were co-registered to OCT images for comparison. Manual segmentation of the airway luminal area, mucosa area, submucosa area and the outer airway wall area were performed for histology and OCT images. Automated segmentation of OCT images employed a despecking filter for pre-processing, a hessian-based filter for lumen and outer airway wall area segmentation, and K-means clustering for mucosa and submucosa ...

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    6. Sex differences in chronic obstructive pulmonary disease evaluated using optical coherence tomography

      Sex differences in chronic obstructive pulmonary disease evaluated using optical coherence tomography

      Although there are more women than men dying of chronic obstructive pulmonary disease (COPD) in the United States and elsewhere, we still do not have a clear understanding of the differences in the pathophysiology of airflow obstruction between the sexes. Optical coherence tomography (OCT) is an emerging imaging technology that has the capability of imaging small bronchioles with resolution approaching histology. Therefore, our objective was to compare OCT-derived airway wall measurements between males and females matched for lung size and in anatomically matched small airways. Subjects 50-80 yrs were enrolled in the British Columbia Lung Health Study and underwent OCT ...

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    7. Airway Imaging in Disease; Gimmick or Useful Tool?

      Airway Imaging in Disease; Gimmick or Useful Tool?

      Airway remodeling is an important pathophysiological mechanism in a variety of chronic airway diseases. Historically investigators have had to use invasive techniques such as histological examination of excised tissue to study airway wall structure. The last several years has seen a proliferation of relatively non-invasive techniques to assess the airway branching pattern, wall thickness and, more recently, airway wall tissue components. These methods include computed tomography, magnetic resonance imaging and optical coherence tomography. These new imaging technologies have become popular because in order to understand the physiology of lung disease it is important we understand the underlying anatomy. However, these ...

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    8. Automated segmentation of lung airway wall area measurements from bronchoscopic optical coherence Tomography imaging

      Automated segmentation of lung airway wall area measurements from bronchoscopic optical coherence Tomography imaging

      Chronic Obstructive Pulmonary Disease (COPD) affects almost 600 million people and is currently the fourth leading cause of death worldwide. COPD is an umbrella term for respiratory symptoms that accompany destruction of the lung parenchyma and/or remodeling of the airway wall, the sum of which result in decreased expiratory flow, dyspnea and gas trapping. Currently, x-ray computed tomography (CT) is the main clinical method used for COPD imaging, providing excellent spatial resolution for quantitative tissue measurements although dose limitations and the fundamental spatial resolution of CT limit the measurement of airway dimensions beyond the 5th generation. To address this ...

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    9. Phenotyping Airways Disease With Optical Coherence Tomography

      Phenotyping Airways Disease With Optical Coherence Tomography

      Airway diseases are a major concern around the world. However, the pace of new drug and biomarker discovery has lagged behind those of other common disorders such as cardiovascular diseases and diabetes. One major barrier in airways research has been the inability to accurately visualize large and small airway remodeling or dysplastic/neoplastic (either pre or early cancerous) changes using non or minimally invasive instruments. The advent of optical coherence tomography (OCT) has the potential to revolutionize airway research and management by allowing investigators and clinicians to visualize the airway with resolution approaching histology without exposing patients to harmful effects ...

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    10. Quantitative Assessment of the Airway Wall Using Computed Tomography and Optical Coherence Tomography

      Ever since the site and nature of airflow obstruction in chronic obstructive pulmonary disease was described by Hogg, Thurlbeck, and Macklem, investigators have been looking for methods to noninvasively measure the airway wall dimensions. Recent advances in computed tomography technology and new computer algorithms have made it possible to visualize and measure the airway wall and lumen without the need for tissue. However, while there is great hope for computed tomographic assessment of airways, it is well known that the spatial resolution does not allow small airways to be visualized and there are still concerns about the sensitivity of these ...

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    11. New and Current Clinical Imaging Techniques To Study Chronic Obstructive Pulmonary Disease

      Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease, characterized by both small airway and parenchymal abnormalities. There is increasing evidence to suggest that these two morphologic phenotypes, while related, may have different clinical presentations, prognosis and therapeutic responses to medications. With the advent of novel imaging modalities, it is now possible to evaluate these two morphologic phenotypes in large clinical studies using non or minially invasive methods such as computed tomography (CT), magentic resonance imaging (MRI) and optical coherence tomography (OCT). In this paper, we provide a pictorial overview of these modalities in the context of COPD and discuss ...

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    12. Airway Wall Thickness Assessed Using Computed Tomography and Optical Coherence Tomography

      Airway Wall Thickness Assessed Using Computed Tomography and Optical Coherence Tomography

      Rationale: Computed tomography (CT) has been shown to reliably measure the airway wall dimensions of medium to large airways. Optical coherence tomography (OCT) is a promising new micron-scale resolution imaging technique that can image small airways 2 mm in diameter or less. Objectives: To correlate OCT measurements of airway dimensions with measurements assessed using CT scans and lung function. Methods: Forty-four current and former smokers received spirometry, CT scans, and OCT imaging at the time of bronchoscopy. Specific bronchial segments were identified and measured using the OCT images and three-dimensional reconstructions of the bronchial tree using CT. Measurements and Main ...

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    1-12 of 12
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  2. Topics in the News

    1. (11 articles) Harvey O. Coxson
    2. (10 articles) Stephen Lam
    3. (9 articles) University of British Columbia
    4. (6 articles) British Columbia Cancer Agency
    5. (4 articles) Pierre M. Lane
    6. (4 articles) Abbot
    7. (2 articles) Grace Parraga
    8. (2 articles) Wei Zhang
    9. (2 articles) Massachusetts General Hospital
    10. (1 articles) Sir Charles Gairdner Hospital
    11. (1 articles) University of Western Australia
    12. (1 articles) Harvard University
    13. (1 articles) The Chinese University of Hong Kong
    14. (1 articles) University of Miami
    15. (1 articles) VU University Amsterdam
    16. (1 articles) David A. Boas
    17. (1 articles) Brett E. Bouma
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    Airway Wall Thickness Assessed Using Computed Tomography and Optical Coherence Tomography Phenotyping Airways Disease With Optical Coherence Tomography Automated segmentation of lung airway wall area measurements from bronchoscopic optical coherence Tomography imaging Airway Imaging in Disease; Gimmick or Useful Tool? Sex differences in chronic obstructive pulmonary disease evaluated using optical coherence tomography Automated segmentation of porcine airway wall layers using optical coherence tomography: comparison with manual segmentation and histology Validation of Airway Wall Measurements by Optical Coherence Tomography in Porcine Airways Bronchial thermoplasty in asthma: 2-year follow-up using optical coherence tomography Optical Coherence Tomography: Critical Tool to Manage Expectations after Cataract Extraction Improving the characterization of ex vivo human brain optical properties using high numerical aperture optical coherence tomography by spatially constraining the confocal parameters Choroidal, macular and ganglion cell layer thickness assessment in Caucasian children measured with spectral domain optical coherence tomography Examination of retinal vascular density changes via optical coherence tomography angiography in patients with glaucoma