1. Articles from Valery Tuchin

    1-6 of 6
    1. A robust model of an OCT signal in a spectral domain

      A robust model of an OCT signal in a spectral domain

      Optical coherence tomography (OCT) relies on ballistic back scattered photons to construct depth resolved optical slices of a specimen. However, the theory of OCT is generally math heavy and unintuitive. In this paper, we propose an approach, and show as many aspects of the OCT signal formation that can be described by using simple math and intuitive physics. The model allowing for simulating a semi-ideal OCT signal from an object with an arbitrary structure is presented.

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    2. Photodynamic opening of the blood-brain barrier and pathways of brain clearing

      Photodynamic opening of the blood-brain barrier and pathways of brain clearing

      A new application of the photodynamic treatment (PDT) is presented for the opening of blood-brain barrier (BBB) and the brain clearing activation that is associated with it, including the use of gold nanoparticles as emerging photosensitizer carriers in PDT. The obtained results clearly demonstrate two pathways for the brain clearing: 1) using PDT-opening of BBB and intravenous injection of FITC-dextran we showed a clearance of this tracer via the meningeal lymphatic system in the subdural space; 2) using optical coherence tomography and intra-parenchymal injection of gold nanorods we observed their clearance through the exit gate of cerebral spinal fluid from ...

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    3. Application of optical coherence tomography for in vivo monitoring of the meningeal lymphatic vessels during opening of blood–brain barrier: mechanisms of brain clearing

      Application of optical coherence tomography for in vivo monitoring of the meningeal lymphatic vessels during opening of blood–brain barrier: mechanisms of brain clearing

      The meningeal lymphatic vessels were discovered 2 years ago as the drainage system involved in the mechanisms underlying the clearance of waste products from the brain. The blood–brain barrier (BBB) is a gatekeeper that strongly controls the movement of different molecules from the blood into the brain. We know the scenarios during the opening of the BBB, but there is extremely limited information on how the brain clears the substances that cross the BBB. Here, using the model of sound-induced opening of the BBB, we clearly show how the brain clears dextran after it crosses the BBB via the ...

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    4. Optical clearing of articular cartilage: a comparison of clearing agents

      Optical clearing of articular cartilage: a comparison of clearing agents

      Optical clearing technique was applied to the problem of OCT imaging of articular cartilage and subchondral bone. We show that optical clearing significantly enhances visualization of articular cartilage and cartilage-bone interface. The effect of different clearing agents was analyzed. For the clearing, iohexol solution and propylene glycol (PG) were used. Clearing was performed in vitro at room temperature by immersion method. Cylindrical osteochondral samples (d=4.8mm) were drilled from bovine lateral femur and stored in phosphate-buffered saline at -20°C until clearing. Monitoring of clearing process was performed using high-speed spectral-domain OCT system providing axial resolution of 5.8 ...

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    5. Imaging of subchondral bone by optical coherence tomography upon optical clearing of articular cartilage

      Imaging of subchondral bone by optical coherence tomography upon optical clearing of articular cartilage

      Optical clearing is an effective method to reduce light scattering of biological tissues that provides significant enhancement of light penetration into the biological tissues making non-invasive diagnosis more feasible. In current report Optical Coherence Tomography (OCT) in conjunction with optical clearing is applied for assessment of deep cartilage layers and cartilage-bone interface. The solution of Iohexol in water has been used as an optical clearing agent. The cartilage-bone boundary becomes visible after 15 min of optical clearing that enabling non-invasive estimation of its roughness: S a = 10 ± 1 µm. The results show that for 0.9 mm thick cartilage optical ...

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    6. Gold nanostructures for OCT imaging of capillary flow

      Gold nanostructures for OCT imaging of capillary flow

      In this paper, plasmon-resonant nanostructures, such as gold nanostars and their silica-coated composites, were used for enhancement of OCT image contrast of water flows in glass capillaries. The contrasting properties of the synthesized nanostars and nanocomposites with silica shell thickness of about 5 nm and 50 nm were compared in the framework of capillary stasis model. The most intensive signal was detected from the nanocomposites with the thickest silica shell. The nanocomposites were characterized by optical spectroscopy and electron microscopy. Nontoxicity of nanostars and nanocomposites up to ~ 3 mg/mL concentration was showed by MTT assay suggesting practical applications of ...

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    1-6 of 6
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  2. Topics in the News

    1. (6 articles) Valery V. Tuchin
    2. (4 articles) Saratov State University
    3. (3 articles) University of Oulu
    4. (3 articles) Matti Kinnunen
    5. (3 articles) Alexander V. Bykov
    6. (1 articles) Igor V. Meglinski
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    Gold nanostructures for OCT imaging of capillary flow Imaging of subchondral bone by optical coherence tomography upon optical clearing of articular cartilage Optical clearing of articular cartilage: a comparison of clearing agents Application of optical coherence tomography for in vivo monitoring of the meningeal lymphatic vessels during opening of blood–brain barrier: mechanisms of brain clearing Photodynamic opening of the blood-brain barrier and pathways of brain clearing A robust model of an OCT signal in a spectral domain Intravascular Imaging-Guided Percutaneous Coronary Intervention: A Universal Approach for Optimization of Stent Implantation Clinical Usefulness of a Novel Optical Coherence Tomography Procedure, “Low Molecular Weight Dextran Infusion Followed by Catheter PUSH (D-PUSH)” Optical Coherence Tomography to Guide Percutaneous Coronary Intervention of the Left Main Coronary Artery: the LEMON study Impact of optical coherence tomography findings on clinical outcomes in ST-segment elevation myocardial infarction patients: a MATRIX (Minimizing Adverse Hemorrhagic Events by Trans-radial Access Site and angioX) OCT sub-study OCTA Multilayer and Multisector Peripapillary Microvascular Modeling for Diagnosing and Staging of Glaucoma Optical coherence tomography angiography for identifying choroidal neovascular membranes: a masked study in clinical practice