1. Articles from Guillermo J. Tearney

    1-24 of 170 1 2 3 4 5 6 7 »
    1. Micro-optical coherence tomography for high-resolution morphologic imaging of cellular and nerval corneal micro-structures

      Micro-optical coherence tomography for high-resolution morphologic imaging of cellular and nerval corneal micro-structures

      We demonstrate the highest resolution (1.5×1.5×1 µm) micrometer optical coherence tomography (µOCT) imaging of the morphologic micro-structure of excised swine and non-human primate corneas. Besides epithelial, stromal, and endothelial cell morphology, this report focuses on investigating the most peripheral corneal nerve fibers, the nerve fibers of the subbasal plexus (SBP). Alterations of SBP nerve density and composition are reportedly linked to major neurologic disorders, such as diabetic neuropathy, potentially indicating earliest onsets of denervation. Here, the fine, hyperreflective, epithelial nerve structures located just above Bowman’s membrane, are i) visualized using our µOCT prototype, ii) validated ...

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    2. OCT and CMR for the Diagnosis of Patients Presenting With MINOCA and Suspected Epicardial Causes

      OCT and CMR for the Diagnosis of Patients Presenting With MINOCA and Suspected Epicardial Causes

      Background OCT is able to identify different morphologic features of coronary plaques that are well known causes of MINOCA. Furthermore, CMR has become the gold standard for detection of myocardial infarction in the setting of MINOCA. Methods In a prospective 2-center study, consecutive patients with MINOCA including ECG features of ischemia associated with corresponding WMAs underwent OCT and CMR. Results Forty patients (mean age: 50 ± 11 years, 62.5% male, 32.5% with ST-segment elevation) were enrolled. Coronary arteries were normal on coronary angiography in 10 patients (25%); 18 patients (45%) presented minimal lumen irregularities, whereas the remaining 12 patients ...

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    3. System and method for facilitating manual and/or automatic volumetric imaging with real-time tension or force feedback using a tethered imaging device

      System and method for facilitating manual and/or automatic volumetric imaging with real-time tension or force feedback using a tethered imaging device

      According to exemplary embodiments of the present disclosure, apparatus, device and method can be provided which can provide imaging of biological tissues, e.g., luminal organs in vivo, using optical techniques in an automatic or semiautomatic manner. The exemplary apparatus, device and method can utilize a tethered capsule catheter with a mechanism for manual, semi-automatic or automatic traversing in the luminal organ with a controlled velocity and/or image quality. The exemplary apparatus can include feedback information about tension applied to the catheter during its movement that can be used to adjust velocity and assure patient comfort and safety for ...

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    4. Imaging intracellular motion with dynamic micro-optical coherence tomography

      Imaging intracellular motion with dynamic micro-optical coherence tomography

      This paper describes a new technology that uses 1-µm-resolution optical coherence tomography (µOCT) to obtain cross-sectional images of intracellular dynamics with dramatically enhanced image contrast. This so-called dynamic µOCT (d-µOCT) is accomplished by acquiring a time series of µOCT images and conducting power frequency analysis of the temporal fluctuations that arise from intracellular motion on a pixel-per-pixel basis. Here, we demonstrate d-µOCT imaging of freshly excised human esophageal and cervical biopsy samples. Depth-resolved d-µOCT images of intact tissue show that intracellular dynamics provides a new contrast mechanism for µOCT that highlights subcellular morphology and activity in ...

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    5. Stromal Nerve Imaging and Tracking Using Micro-Optical Coherence Tomography

      Stromal Nerve Imaging and Tracking Using Micro-Optical Coherence Tomography

      urpose : To image, track and map the nerve fiber distribution in excised rabbit corneas over the entire stromal thickness using micro-optical coherence tomography (µOCT) to develop a screening tool for early peripheral neuropathy. Methods : Excised rabbit corneas were consecutively imaged by a custom-designed µOCT prototype and a commercial laser scanning fluorescence confocal microscope. The µOCT images with a field of view of approximately 1 × 1 mm were recorded with axial and transverse resolutions of approximately 1 µm and approximately 4 µm, respectively. In the volumetric µOCT image data, network maps of hyper-reflective, branched structures traversing different stromal compartments were segmented ...

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    6. Devices, systems, methods and storage mediums using full range optical coherence tomography

      Devices, systems, methods and storage mediums using full range optical coherence tomography

      One or more devices, systems, methods and storage mediums for performing continuously, full range optical coherence tomography (OCT) without losing A-lines are provided. Examples of such applications include imaging, evaluating and diagnosing biological objects, such as, but not limited to, for cardio and/or ophthalmic applications, and being obtained via one or more optical instruments, such as, but not limited to, optical probes (e.g., common path probes), catheters, endoscopes, phase shift units (e.g., galvanometer scanner) and bench top systems. Preferably, the OCT devices, systems methods and storage mediums include or involve a phase shift device including at least ...

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    7. All fiber polarization insensitive detection for spectrometer based optical coherence tomography using optical switch

      All fiber polarization insensitive detection for spectrometer based optical coherence tomography using optical switch

      Polarization dependent image artifacts are common in optical coherence tomography imaging. Polarization insensitive detection scheme for swept source based optical coherence tomography systems is well established but is yet to be demonstrated for all fiber spectrometer-based Fourier domain optical coherence tomography systems. In this work, we present an all fiber polarization insensitive detection scheme for spectrometer based optical coherence tomography systems. Images from chicken breast muscle tissue were acquired to demonstrate the effectiveness of this scheme for the conventional Fourier domain optical coherence tomography system.

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    8. 3D cellular-resolution imaging in arteries using few-mode interferometry

      3D cellular-resolution imaging in arteries using few-mode interferometry

      Article Open Access Published: 21 November 2019 3D cellular-resolution imaging in arteries using few-mode interferometry Biwei Yin , Zhonglie Piao , Kensuke Nishimiya , Chulho Hyun , Joseph A. Gardecki , Adam Mauskapf , Farouc A. Jaffer & Guillermo J. Tearney Light: Science & Applications volume 8 , Article number: 104 ( 2019 ) Cite this article Article metrics 3 Altmetric Metrics details Abstract Cross-sectional visualisation of the cellular and subcellular structures of human atherosclerosis in vivo is significant, as this disease is fundamentally caused by abnormal processes that occur at this scale in a depth-dependent manner. However, due to the inherent resolution-depth of focus tradeoff of conventional focusing optics, today ...

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    9. Excess mucus viscosity and airway dehydration impact COPD airway clearance

      Excess mucus viscosity and airway dehydration impact COPD airway clearance

      The mechanisms by which cigarette smoking impairs airway mucus clearance are not well understood. We recently established a ferret model of cigarette smoke-induced chronic obstructive pulmonary disease (COPD) exhibiting chronic bronchitis. We investigated the effects of cigarette smoke on mucociliary transport (MCT). Adult ferrets were exposed to cigarette smoke for 6 months, with in vivo mucociliary clearance (MCC) measured by Tc-labeled DTPA (Tc-DTPA) retention. Excised tracheae were imaged with micro-optical coherence tomography. Mucus changes in primary human airway epithelial cells and ex vivo ferret airways were assessed by histology and particle tracking microrheology. Linear mixed models for repeated measures identified ...

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    10. Co-cultured microfluidic model of the airway optimized for microscopy and micro-optical coherence tomography imaging

      Co-cultured microfluidic model of the airway optimized for microscopy and micro-optical coherence tomography imaging

      We have developed a human bronchial epithelial (HBE) cell and endothelial cell co-cultured microfluidic model to mimic the in vivo human airway. This airway-on-a-chip was designed with a central epithelial channel and two flanking endothelial channels, with a three-dimensional monolayers of cells growing along the four walls of the channel, forming central clear lumens. These cultures mimic airways and microvasculature in vivo . The central channel cells are grown at air-liquid interface and show features of airway differentiation including tight-junction formation, mucus production, and ciliated cells. Combined with novel micro-optical coherence tomography, this chip enables functional imaging of the interior of ...

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    11. Intranasal micro-optical coherence tomography imaging for cystic fibrosis studies

      Intranasal micro-optical coherence tomography imaging for cystic fibrosis studies

      Cystic fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Although impairment of mucociliary clearance contributes to severe morbidity and mortality in people with CF, a clear understanding of the pathophysiology is lacking. This is, in part, due to the absence of clinical imaging techniques capable of capturing CFTR-dependent functional metrics at the cellular level. Here, we report the clinical translation of a 1-μm resolution micro-optical coherence tomography (μOCT) technology to quantitatively characterize the functional microanatomy of human upper airways. Using a minimally invasive intranasal imaging approach, we performed a clinical ...

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    12. Imaging the Human Prostate Gland Using 1-μm-Resolution Optical Coherence Tomography

      Imaging the Human Prostate Gland Using 1-μm-Resolution Optical Coherence Tomography

      Context.— The accuracy of needle biopsy for the detection of prostate cancer is limited by well-known sampling errors. Thus, there is an unmet need for a microscopic screening tool that can screen large regions of the prostate comprehensively for cancer. Previous prostate imaging by optical coherence tomography (OCT) has had insufficient resolution for imaging cellular features related to prostate cancer. We have recently developed micro-optical coherence tomography (μOCT) that generates depth-resolved tissue images at a high frame rate with an isotropic resolution of 1 μm. Objective.— To demonstrate that optical images obtained with μOCT provide cellular-level contrast in prostate specimens ...

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    13. Plaque burden can be assessed using intravascular optical coherence tomography and a dedicated automated processing algorithm: a comparison study with intravascular ultrasound

      Plaque burden can be assessed using intravascular optical coherence tomography and a dedicated automated processing algorithm: a comparison study with intravascular ultrasound

      Aims Plaque burden (PB) measurement using intravascular optical coherence tomography (IVOCT) is currently thought to be inferior to intravascular ultrasound (IVUS). We developed an automated IVOCT image processing algorithm to enhance the external elastic lamina (EEL) contour. Thus, we investigated the accuracies of standard IVOCT and an IVOCT enhancement algorithm for measuring PB using IVUS as the reference standard. Methods and results The EEL-enhancement algorithm combined adaptive attenuation compensation, exponentiation, angular registration, and image averaging using three sequential frames. In two different laboratories with intravascular imaging expertise, PB was quantified on 200 randomized, matched IVOCT and IVUS images by four ...

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    14. Methods, systems, arrangements and computer-accessible medium for providing micro-optical coherence tomography procedures

      Methods, systems, arrangements and computer-accessible medium for providing micro-optical coherence tomography procedures

      Exemplary apparatus and method can be provided for obtaining data regarding a plurality of samples. For example, using at least one arrangement, it is possible to receive interferometric information that is based on radiations provided from a reference and the samples that are provided in respective chambers. Alternatively and/or in addition, based on the interferometric information, it is possible to discriminate between agents to identify a particular agent that affects a particular function within at least one of the samples.

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    15. Imaging the Human Prostate Gland Using 1-μm-Resolution Optical Coherence Tomography

      Imaging the Human Prostate Gland Using 1-μm-Resolution Optical Coherence Tomography

      Context.— The accuracy of needle biopsy for the detection of prostate cancer is limited by well-known sampling errors. Thus, there is an unmet need for a microscopic screening tool that can screen large regions of the prostate comprehensively for cancer. Previous prostate imaging by optical coherence tomography (OCT) have had insufficient resolution for imaging cellular features related to prostate cancer. We have recently developed micro-optical coherence tomography (μOCT) that generates depth-resolved tissue images at a high frame rate with an isotropic resolution of 1 μm. Objective.— To demonstrate that optical images obtained with μOCT provide cellular-level contrast in prostate specimens ...

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    16. In Vivo and Ex Vivo Microscopy: Moving Toward the Integration of Optical Imaging Technologies Into Pathology Practice

      In Vivo and Ex Vivo Microscopy: Moving Toward the Integration of Optical Imaging Technologies Into Pathology Practice

      The traditional surgical pathology assessment requires tissue to be removed from the patient, then processed, sectioned, stained, and interpreted by a pathologist using a light microscope. Today, an array of alternate optical imaging technologies allow tissue to be viewed at high resolution, in real time, without the need for processing, fixation, freezing, or staining. Optical imaging can be done in living patients without tissue removal, termed in vivo microscopy, or also in freshly excised tissue, termed ex vivo microscopy. Both in vivo and ex vivo microscopy have tremendous potential for clinical impact in a wide variety of applications. However, in ...

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    17. Intravascular optical coherence tomography

      Intravascular optical coherence tomography

      Intravascular optical coherence tomography (IVOCT) began at MIT in the early 1990’s with the recognition that OCT could be used for clinical applications other than ophthalmology. Initial steps made there towards IVOCT feasibility included the acquisition of cadaver arterial images demonstrating the capacity of OCT to visualize depth-resolved architectural detail of plaque 5 and the development of the first mechanical scanning catheter. 6 Early histopathologic correlation studies from cadaver arteries demonstrated that IVOCT was capable of distinguishing the major fibrous, fibrocalcific, and lipid-rich plaque types and also potentially identifying inflammation as manifested by macrophage accumulations. 7, 8 Data from ...

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    18. Visualizing cellular markers of sensorineural hearing loss in the murine cochlea using micro-optical coherence tomography

      Visualizing cellular markers of sensorineural hearing loss in the murine cochlea using micro-optical coherence tomography

      Although sensorineural hearing loss (SNHL) affects 600 million people globally and its prevalence is increasing, therapies remain limited. Advances in therapy development for SNHL are slow because we do not possess a method for visualizing the cochlea’s interior in living humans and relating visualized pathology to a patient’s hearing ability. To this end, we are investigating the ability of micro-optical coherence tomography (µOCT), a low-coherence interferometric imaging technique that requires no contrast agent and improves upon standard OCT in resolution and depth of focus, to visualize the micron-sized cellular structures in the cochlea. We recently demonstrated µOCT’s ...

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    19. Optical coherence tomography-guided laser marking with tethered capsule endomicroscopy

      Optical coherence tomography-guided laser marking with tethered capsule endomicroscopy

      Tethered capsule endomicroscopy (TCE) is a new method for performing comprehensive microstructural OCT imaging of gastrointestinal (GI) tract in unsedated patients in a well-tolerated and cost-effective manner. These features of TCE bestow it with significant potential to improve the screening, surveillance and management of various upper gastrointestinal diseases. To achieve clinical adoption of this imaging technique, it is important to validate it with co-registered histology, the current diagnostic gold standard. One such method for co-registering OCT images with histology is laser cautery marking, previously demonstrated using a balloon-centering OCT catheter that operates in conjunction with sedated endoscopy. With laser marking ...

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    20. Contrast enhancement of microscopic birefringent crystals using polarization sensitive micro-optical coherence tomography

      Contrast enhancement of microscopic birefringent crystals using polarization sensitive micro-optical coherence tomography

      Background: Birefringent crystals such as cholesterol and monosodium urate have recently been identified as possible pharmacologic targets for the treatment of coronary artery disease. The size of these crystals can be very small (on the order of 1 µm), making them difficult to identify. To image these microscopic crystals and enhance contrast, we modified existing micro optical coherence tomography system so that it was capable of obtaining polarization-sensitive images (PS-µOCT). A spectrometer-based PS-µOCT system was developed using a 270 nm wide broadband light source centered at 765 nm. Light was polarized using a polarizer and coupled to a ...

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    21. Cellular-resolution, extended depth of focus optical coherence tomography catheter toward in vivo cardiovascular imaging

      Cellular-resolution, extended depth of focus optical coherence tomography catheter toward in vivo cardiovascular imaging

      Optical coherence tomography (OCT) has been a useful clinical tool for diagnosing coronary artery disease through a flexible catheter, but its full promise relies on resolving cellular and sub-cellular structures in vivo. Previously, visualizing cellular structures through an imaging catheter is not possible due to limited depth of focus (DOF) of a tightly focused Gaussian beam: typically, a Gaussian beam with 2-3 μm resolution has a DOF within 100 μm, which is not sufficient for in vivo catheter imaging. Therefore, we developed a self-imaging wavefront division optical system that generates a coaxially-focused multimode (CAFM) beam with a DOF that is ...

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    22. Automated detection of esophageal dysplasia in in vivo optical coherence tomography images of the human esophagus

      Automated detection of esophageal dysplasia in in vivo optical coherence tomography images of the human esophagus

      Catheter-based Optical Coherence Tomography (OCT) devices allow real-time and comprehensive imaging of the human esophagus. Hence, they provide the potential to overcome some of the limitations of endoscopy and biopsy, allowing earlier diagnosis and better prognosis for esophageal adenocarcinoma patients. However, the large number of images produced during every scan makes manual evaluation of the data exceedingly difficult. In this study, we propose a fully automated tissue characterization algorithm, capable of discriminating normal tissue from Barrett’s Esophagus (BE) and dysplasia through entire three-dimensional (3D) data sets, acquired in vivo. The method is based on both the estimation of the ...

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    23. Clinical Translation of Tethered Confocal Microscopy Capsule for Unsedated Diagnosis of Eosinophilic Esophagitis

      Clinical Translation of Tethered Confocal Microscopy Capsule for Unsedated Diagnosis of Eosinophilic Esophagitis

      Esophagogastroduodenoscopy (EGD) is a widely used procedure, posing significant financial burden on both healthcare systems and patients. Moreover, EGD is time consuming, sometimes difficult to tolerate, and suffers from an imperfect diagnostic yield as the limited number of collected biopsies does not represent the whole organ. In this paper, we report on technological and clinical feasibility of a swallowable tethered endomicroscopy capsule, which is administered without sedation, to image large regions of esophageal and gastric mucosa at the cellular level. To demonstrate imaging capabilities, we conducted a human pilot study (n = 17) on Eosinophilic Esophagitis (EoE) patients and healthy volunteers ...

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    1-24 of 170 1 2 3 4 5 6 7 »
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    1. (166 articles) Guillermo J. Tearney
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    Handbook of Optical Coherence Tomography (Book) Heart wall velocimetry and exogenous contrast-based cardiac flow imaging in Drosophila melanogaster using Doppler optical coherence tomography Imaging the subcellular structure of human coronary atherosclerosis using micro–optical coherence tomography Automated segmentation and characterization of esophageal wall in vivo by tethered capsule optical coherence tomography endomicroscopy Feature of the Week 04/24/2016: μOCT Imaging Using Depth of Focus Extension by Self-Imaging Wavefront Division in a Common-Path Fiber Optic Probe Postdoctoral Research Fellowships in Optical Coherence Tomography at Massachusetts General Hosptial Correlation between optical coherence tomography, multifocal electroretinogram findings and visual acuity in diabetic macular edema Ciliary body length revisited by anterior segment optical coherence tomography: implications for safe access to the pars plana for intravitreal injections Evaluation of retinal vascular structure after epiretinal membrane surgery by optical coherence tomography angiography Bivalirudin vs. Heparin on Radial Artery Thrombosis during Transradial Coronary Intervention: An Optical Coherence Tomography Study Superficial Calcification With Rotund Shape Is Associated With Carotid Plaque Rupture: An Optical Coherence Tomography Study Longitudinal retinal layer changes in preclinical Alzheimer’s disease