1. Articles in category: Pulmonology

    1-24 of 258 1 2 3 4 ... 9 10 11 »
    1. Mapping the human pulmonary venoatrial junction with optical coherence tomography

      Mapping the human pulmonary venoatrial junction with optical coherence tomography

      Imaging guidance provided by optical coherence tomography (OCT) could improve the outcomes of atrial fibrillation (AF) ablation by providing detailed structural information of the pulmonary veins, which are critical targets during ablation. In this study, stitched volumetric OCT images of venoatrial junctions from post-mortem human hearts were acquired and compared to histology. Image features corresponding to venous media and myocardial sleeves, as well as fiber orientation and fibrosis, were identified and found to vary between veins. Imaging of detailed tissue architecture could improve understanding of the AF structural substrate within the pulmonary veins and assist the guidance of ablation procedures.

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    2. Acute Airway Effects of Bronchial Thermoplasty Assessed by Optical Coherence Tomography (OCT)

      Acute Airway Effects of Bronchial Thermoplasty Assessed by Optical Coherence Tomography (OCT)

      Background: Bronchial Thermoplasty (BT) is an endoscopic treatment for severe asthma targeting airway smooth muscle (ASM) with thermal energy. The extent of treatment effect is largely unknown. Optical coherence tomography (OCT) is a high resolution imaging technique, using near-infrared light, that generates near-histology cross sectional images of the airway wall. Aim: Assess the extent of acute airway wall effects of BT with OCT and compare these to the untreated right middle lobe (RML). Methods: 15 severe asthma patients were treated with BT. During the third procedure, OCT imaging was performed in BT treated (sub)segmental airways in the upper lobes ...

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    3. Point-of-care endoscopic optical coherence tomography detects changes in mucosal thickness in ARDS due to smoke inhalation and burns

      Point-of-care endoscopic optical coherence tomography detects changes in mucosal thickness in ARDS due to smoke inhalation and burns

      Background The prevalence of acute respiratory distress syndrome (ARDS) in mechanically ventilated burn patients is 33%, with mortality varying from 11–46% depending on ARDS severity. Despite the new Berlin definition for ARDS, prompt bedside diagnosis is lacking. We developed and tested a bedside technique of fiberoptic-bronchoscopy-based optical coherence tomography (OCT) measurement of airway mucosal thickness (MT) for diagnosis of ARDS following smoke inhalation injury (SII) and burns. Methods 16 female Yorkshire pigs received SII and 40% thermal burns. OCT MT and PaO 2 -to-FiO 2 ratio (PFR) measurements were taken at baseline, after injury, and at 24, 48, and ...

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    4. Optical coherence tomography in the diagnosis of sarcoidosis of lung and other organs

      Optical coherence tomography in the diagnosis of sarcoidosis of lung and other organs

      Sarcoidosis is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomas. The disease can affect the lungs, skin, lymph nodes, eyes, liver, heart, and brain. As for the eyes it occupies 3-4 place among organs-target. Diagnosis of eye sarcoidosis is quite complicated and is usually found in ophthalmologic examination. Objective: Studying of diagnostic significance of additional methods of ophthalmology examination for sarcoidosis of lung and other localizations. Methods: It was a prospective investigation. The study group consisted of patients with the first identified sarcoidosis in different organs. The control group consisted of patients with tuberculosis ...

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    5. Combined anatomical optical coherence tomography and intraluminal pressure reveal viscoelasticity of the in vivo airway

      Combined anatomical optical coherence tomography and intraluminal pressure reveal viscoelasticity of the in vivo airway

      It is hypothesized that the local, viscoelastic (time-dependent) properties of the airway are important to accurately model and ultimately predict dynamic airway collapse in airway obstruction. Toward this end, we present a portable, endoscopic, swept-source anatomical optical coherence tomography (aOCT) system combined with a pressure catheter to capture local airway dynamics in vivo during respiration. aOCT scans were performed in the airways of a mechanically ventilated pig under paralysis with dynamic and static ventilation protocols. Validation of dynamic aOCT luminal cross-sectional area (CSA) measurements against Cine CT, obtained during the same exam, showed an aggregate difference of 15  %    ±  3  %  . aOCT-derived ...

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    6. Geometric Validation of Continuous, Finely-Sampled 3D Reconstructions from aOCT and CT in Upper Airway Models

      Geometric Validation of Continuous, Finely-Sampled 3D Reconstructions from aOCT and CT in Upper Airway Models

      Identification and treatment of obstructive airway disorders (OADs) is greatly aided by imaging of the geometry of the airway lumen. Anatomical optical coherence tomography (aOCT) is a promising high-speed and minimally-invasive endoscopic imaging modality for providing micrometer-resolution scans of the upper airway. Resistance to airflow in OADs is directly caused by reduction in luminal cross-sectional area (CSA). It is hypothesized that aOCT can produce airway CSA measurements as accurate as that from computed tomography (CT). Scans of machine hollowed cylindrical tubes were used to develop methods for segmentation and measurement of airway lumen in CT and aOCT. Simulated scans of ...

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    7. Significances of spirometry and impulse oscillometry for detecting small airway disorders assessed with endobronchial optical coherence tomography in COPD

      Significances of spirometry and impulse oscillometry for detecting small airway disorders assessed with endobronchial optical coherence tomography in COPD

      Background: Spirometry confers limited value for identifying small-airway disorders (SADs) in early-stage COPD, which can be detected with impulse oscillometry (IOS) and endobronchial optical coherence tomography (EB-OCT). Whether IOS is useful for reflecting small-airway morphological abnormalities in COPD remains unclear. Objectives: To compare the diagnostic value of spirometry and IOS for identifying SADs in heavy-smokers and COPD based on the objective assessment with EB-OCT. Methods: We recruited 59 COPD patients (stage I, n=17; stage II, n=18; stage III–IV, n=24), 26 heavy-smokers and 21 never-smokers. Assessments of clinical characteristics, spirometry, IOS and EB-OCT were performed. Receiver operation ...

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    8. Bronchial Thermoplasty-Induced Acute Airway Effects Assessed with Optical Coherence Tomography in Severe Asthma

      Bronchial Thermoplasty-Induced Acute Airway Effects Assessed with Optical Coherence Tomography in Severe Asthma

      Background: Bronchial thermoplasty (BT) is an endoscopic treatment for severe asthma targeting airway smooth muscle (ASM) with radiofrequent energy. Although implemented worldwide, the effect of BT treatment on the airways is unclear. Optical coherence tomography (OCT) is a novel imaging technique, based on near-infrared light, that generates high-resolution cross-sectional airway wall images. Objective: To assess the safety and feasibility of OCT in severe asthma patients and determine acute airway effects of BT by OCT and compare these to the untreated right middle lobe (RML). Methods: Severe asthma patients were treated with BT (TASMA trial). During the third BT procedure, OCT ...

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    9. Upper airway reconstruction using long‐range optical coherence tomography: Effects of airway curvature on airflow resistance

      Upper airway reconstruction using long‐range optical coherence tomography: Effects of airway curvature on airflow resistance

      Objectives Adenotonsillectomy (AT) is commonly used to treat upper airway obstruction in children, but selection of patients who will benefit most from AT is challenging. The need for diagnostic evaluation tools without sedation, radiation, or high costs has motivated the development of long‐range optical coherence tomography (LR‐OCT), providing real‐time cross‐sectional airway imaging during endoscopy. Since the endoscope channel location is not tracked in conventional LR‐OCT, airway curvature must be estimated and may affect predicted airway resistance. The study objective was to assess effects of three realistic airway curvatures on predicted airway resistance using computational fluid ...

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    10. Upper airway imaging in sleep-disordered breathing

      Upper airway imaging in sleep-disordered breathing

      Our understanding of sleep-disordered breathing has evolved considerably over the past three decades, and clinical techniques of evaluation have progressed tremendously. Myriad imaging techniques are now available for the physician to approach the dynamic features resulting in turbulent airflow, upper airway narrowing or collapse at different levels. Controversy exists in the choice of investigations, probably because the best evaluation should be a combination of different techniques. Physical, radiographic, endoscopic and acoustic evaluations could be integrated to understand the degree and the levels of airway reduction and/or obstruction in a given patient. This review focuses on cost-effective and easily implemented ...

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    11. Needle-based Optical Coherence Tomography to Guide Transbronchial Lymph Node Biopsy

      Needle-based Optical Coherence Tomography to Guide Transbronchial Lymph Node Biopsy

      Background: Transbronchial needle aspiration (TBNA), often used to sample lymph nodes for lung cancer staging , is subject to sampling error even when performed with endobronchial ultrasound. Optical coherence tomography (OCT) is a high-resolution imaging modality that rapidly generates helical cross-sectional images. We aim to determine if needle-based OCT can provide microstructural information in lymph nodes that may be used to guide TBNA, and improve sampling error. Methods: We performed ex vivo needle-based OCT on thoracic lymph nodes from patients with and without known lung cancer. OCT imaging features were compared against matched histology. Results: OCT imaging was performed in 26 ...

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    12. Optical coherence tomography (OCT) imaging of dynamic airway behavior in an asthma model

      Optical coherence tomography (OCT) imaging of dynamic airway behavior in an asthma model

      To better understand bronchoconstriction in asthma, it is critical to dynamically visualize airway behavior in vivo. However, currently available imaging techniques do not have sufficient temporal and spatial resolution to investigate airway dynamics. We propose to use endobronchial Optical Coherence Tomography (OCT) to provide real-time cross-sectional images of airway dynamics with a high spatial resolution. Our aim was to study the structure and function of spatially distinct airways during tidal breathing (TB), breath-holds (BH) at end inspiration, and in a response to single deep inspiration (DI) and multiple DI (MDI) in a preclinical sheep asthma model. Anesthetized and mechanically ventilated ...

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    13. A study of the effects of supine position and fluid intake on normal airway geometry using anatomical optical coherence tomography

      A study of the effects of supine position and fluid intake on normal airway geometry using anatomical optical coherence tomography

      Airway inhalation injuries are present in up to a third of all major burns patients and are the leading cause of mortality among this population. Understanding the mechanism of injury could minimise oedema (swelling) and airway damage. In this study, we present an anatomical OCT (aOCT) imaging system, based on a 1300-nm wavelength, high-speed, long-range MEMS-VCSEL swept laser source, for real-time volumetric imaging and assessment of inhalation injuries in airways up to 3 cm in diameter. A custom fibre-optic probe with GRIN lens and micro prism is inserted though the nasal passage. Airway cross-sectional images acquired are used to assess ...

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    14. Multimodal imaging of lung tissue dynamics in mechanically ventilated rats with optical coherence tomography and intravital microscopy

      Multimodal imaging of lung tissue dynamics in mechanically ventilated rats with optical coherence tomography and intravital microscopy

      The understanding of alveolar mechanics is an essential step towards new and more protective ventilation strategies which are of dare need for the treatment of diseases of lung tissue and the airways. Such ailments become a major task for medical care and health care systems in modern industrial countries in the future. Besides the obvious importance as life-saving intervention, the mechanical strain and processes on the level of gas exchange are still insufficiently understood. Therefore, it is of great interest to characterize lung tissue and tissue dynamics during artificial ventilation at the alveolar level. 4D Optical coherence tomography (OCT) in ...

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    15. Optical coherence tomography and autofluorescence microscopy of respiratory ciliated epithelia

      Optical coherence tomography and autofluorescence microscopy of respiratory ciliated epithelia

      Efficient mucociliary clearance is necessary to protect the respiratory tract from infection. Mucociliary dysfunction is common in respiratory diseases including asthma, chronic obstructive pulmonary disease, and cystic fibrosis. Rescuing mucociliary clearance by stimulating the metabolism of respiratory ciliated epithelia could offer new treatments for respiratory diseases. However, the coupling between cellular metabolism and mechanical output in respiratory ciliated epithelia is poorly understood. We propose to study this coupling with autofluorescence microscopy and optical coherence tomography (OCT), to measure cellular metabolism and ciliary motility, respectively. The autofluorescent metabolic co-enzymes NAD(P)H and FAD provide non-invasive measures of metabolism through the ...

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    16. Early Cancer Detection (Book Chapter)

      Early Cancer Detection (Book Chapter)

      Lung cancer is the leading cause of cancer deaths worldwide as the majority of patient shave advanced disease at diagnosis.  Detection and early treatment of pre-invasive and minimally invasive lung cancer can significantly improve the current 5-year survival of <18%,  Endoscopic optical imaging (such as autoflourescence imaging), NBI, and OCT provide sensitive means to rapidly scan the central airways , in order to detect early lung cancer for biopsy confirmation and delineation of the extent of the tumor spread to guide treatment.

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    17. Optical Coherence Tomography: A Review (Book Chapter)

      Optical Coherence Tomography: A Review (Book Chapter)

      Optical coherence tomography (OCT), with polarization-sensitive (PS), Doppler, and autofluorescence (AF) capabilities, is emerging as a promising bronchoscopic diagnostic tool. In the upper and central airways, it allows accurate real-time airway measurements to assist bronchoscopic assessment of obstructive sleep apnea, severity of tracheomalacia, airway stenosis, or extent of tumor involvement into the bronchial wall or distally beyond the bronchoscopic view. OCT can visualize cellular and extracellular structures at and below the tissue surface with near histologic resolution as well as to provide three-dimensional imaging of the airways. Blood vessels in the bronchial wall or peribronchial space can be displayed using ...

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    18. Real-Time Identification of In Situ Pulmonary Nodule and Pathology Using Optical Coherence Tomography

      Real-Time Identification of In Situ Pulmonary Nodule and Pathology Using Optical Coherence Tomography

      The incidence of indeterminate pulmonary nodules (IPN) and ground glass opacities (GGO) is increasing. Small IPN may be difficult to localize in the operating room using a minimally invasive approach. Optical coherence tomography (OCT) utilizes interference of light waves to provide high-resolution, cross-sectional images of the internal microstructure by measuring back-reflected light. This approach can deliver video rate images of tissue structure on the micron scale and can be used to identify nodules and provide realtime histology-like images without actual removal of tissue to detect lung lesions.

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    19. Flexible needle with integrated optical coherence tomography probe for imaging during transbronchial tissue aspiration

      Flexible needle with integrated optical coherence tomography probe for imaging during transbronchial tissue aspiration

      Transbronchial needle aspiration (TBNA) of small lesions or lymph nodes in the lung may result in nondiagnostic tissue samples. We demonstrate the integration of an optical coherence tomography (OCT) probe into a 19-gauge flexible needle for lung tissue aspiration. This probe allows simultaneous visualization and aspiration of the tissue. By eliminating the need for insertion and withdrawal of a separate imaging probe, this integrated design minimizes the risk of dislodging the needle from the lesion prior to aspiration and may facilitate more accurate placement of the needle. Results from in situ imaging in a sheep lung show clear distinction between ...

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    20. Optical coherence tomography for identification and quantification of human airway wall layers

      Optical coherence tomography for identification and quantification of human airway wall layers

      Background High-resolution computed tomography has limitations in the assessment of airway wall layers and related remodeling in obstructive lung diseases. Near infrared-based optical coherence tomography (OCT) is a novel imaging technique that combined with bronchoscopy generates highly detailed images of the airway wall. The aim of this study is to identify and quantify human airway wall layers both ex-vivo and in-vivo by OCT and correlate these to histology. Methods Patients with lung cancer, prior to lobectomy, underwent bronchoscopy including in-vivo OCT imaging. Ex-vivo OCT imaging was performed in the resected lung lobe after needle insertion for matching with histology. Airway ...

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    21. Automated segmentation and quantification of airway mucus with endobronchial optical coherence tomography

      Automated segmentation and quantification of airway mucus with endobronchial optical coherence tomography

      We propose a novel suite of algorithms for automatically segmenting the airway lumen and mucus in endobronchial optical coherence tomography (OCT) data sets, as well as a novel approach for quantifying the contents of the mucus. Mucus and lumen were segmented using a robust, multi-stage algorithm that requires only minimal input regarding sheath geometry. The algorithm performance was highly accurate in a wide range of airway and noise conditions. Mucus was classified using mean backscattering intensity and grey level co-occurrence matrix (GLCM) statistics. We evaluated our techniques in vivo in asthmatic and non-asthmatic volunteers.

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    22. Visualization and Detection of Ciliary Beating Pattern and Frequency in the Upper Airway using Phase Resolved Doppler Optical Coherence Tomography

      Visualization and Detection of Ciliary Beating Pattern and Frequency in the Upper Airway using Phase Resolved Doppler Optical Coherence Tomography

      Ciliary motion plays a critical role in the overall respiratory health of the upper airway. These cilia beat at a native frequency and in a synchronized pattern to continuously transport foreign particulate trapped in a layer of mucous out of the upper airway. Disruption of ciliary motion can lead to severe respiratory diseases and compromised respiratory function. Currently, the study of cilia requires expensive high speed cameras and high powered microscopes which is unsuitable for in vivo imaging and diagnosis. Doppler based optical coherence tomography has the potential to visualize the microscopic motion of cilia during their beating cycle. We ...

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    1-24 of 258 1 2 3 4 ... 9 10 11 »
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