1. Articles from L. A. Matveev

    1-7 of 7
    1. Semi-analytical full-wave model for simulations of scans in optical coherence tomography with accounting for beam focusing and the motion of scatterers

      Semi-analytical full-wave model for simulations of scans in optical coherence tomography with accounting for beam focusing and the motion of scatterers

      A full-wave model for simulating images in spectral-domain optical coherence tomography (OCT) with rigorous accounting for the beam-focusing effects is developed. Due to the analytical description of beam focusing, the model is computationally rather efficient. It also uses a rigorous numerical summation of the contributions of the localized sub-resolution scatterers, accounting for variations in the phase-amplitude parameters of the incident and backscattered optical waves, with a subsequent integration of the latter over the objective aperture. In the limit of a weakly focused beam, the developed model has allowed for the validatation of the earlier proposed simplified model with a constant-radius ...

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    2. In-vivo longitudinal imaging of microvascular changes in irradiated oral mucosa of radiotherapy cancer patients using optical coherence tomography

      In-vivo longitudinal imaging of microvascular changes in irradiated oral mucosa of radiotherapy cancer patients using optical coherence tomography

      Mucositis is the limiting toxicity of radio(chemo)therapy of head and neck cancer. Diagnostics, prophylaxis and correction of this condition demand new accurate and objective approaches. Here we report on an in vivo longitudinal monitoring of the oral mucosa dynamics in 25 patients during the course of radiotherapy of oropharyngeal and nasopharyngeal cancer using multifunctional optical coherence tomography (OCT). A spectral domain OCT system with a specially-designed oral imaging probe was used. Microvasculature visualization was based on temporal speckle variations of the full complex signal evaluated by high-pass filtering of 3D data along the slow scan axis. Angiographic image ...

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    3. Multimodal Optical Coherence Tomography in Visualization of Brain Tissue Structure at Glioblastoma (Experimental Study)

      Multimodal Optical Coherence Tomography in Visualization of Brain Tissue Structure at Glioblastoma (Experimental Study)

      The aim of the investigation was to evaluate the performance of multimodal OCT (MM OCT) for differential diagnostics of normal and diseased brain tissue using an experimental model of glioblastoma. Materials and Methods. The spectral domain MM OCT device developed at the Institute of Applied Physics of the Russian Academy of Sciences (Nizhny Novgorod, Russia) was used for the study. It provides two modes of investigation: cross-polarization OCT (CP OCT) and microangiographic OCT (MA OCT). The instrument features the following characteristics: rate of information gathering — 20,000 A-scans per second; wavelength — 1.3 µm; shot size — ~4 × 2 mm; lateral ...

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    4. The Development of the Methodology of Monitoring Experimental Tumors Using Multimodal Optical Coherence Tomography: the Choice of an Optimal Tumor Model

      The Development of the Methodology of Monitoring Experimental Tumors Using Multimodal Optical Coherence Tomography: the Choice of an Optimal Tumor Model

      The objective of the research was to study the features of transplantation, growth and visualization of experimental tumors of animals, using multi-functional optical coherence tomography (OCT) to develop the methodology of evaluation of individual tumor response to anti-cancer therapy. Materials and Methods. The research was carried out using an experimental high-speed spectral-domain multimodal OCT system developed at the Institute of Applied Physics of the Russian Academy of Sciences (Russia). The technical characteristics of the system are the following: speed of information acquisition, 20,000 А-scans per second; 1.3 μm wavelength; frame size, approximately 4×2 mm; lateral resolution, 25 ...

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    5. Recent Trends in Multimodal Optical Coherence Tomography. II. The Correlation-Stability Approach in OCT Elastography and Methods for Visualization of Microcirculation

      Recent Trends in Multimodal Optical Coherence Tomography. II. The Correlation-Stability Approach in OCT Elastography and Methods for Visualization of Microcirculation

      The second part of this paper continues the discussion of possibilities for combining functionally different types of biomedical characterization of tissues using optical coherence tomography (OCT). In the first part, polarization-sensitive imaging and conventional approaches to elastographic mapping in OCT were considered. Here, we consider an unconventional approach to elastographic mapping based on the analysis of variability of OCT images of the deformed tissue, omitting the stage of the displacement-field reconstruction. We also discuss methods for quantification of blood flow and visualization of microvasculature, some of which have much in common with the elastographic approach based on the analysis of ...

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    6. A model for simulating speckle-pattern evolution based on close to reality procedures used inspectral-domain OCT

      A model for simulating speckle-pattern evolution based on close to reality procedures used inspectral-domain OCT

      A robust model for simulating speckle-pattern evolution in optical coherence tomography (OCT) depending on the OCT system parameters and tissue deformation is reported. The model is based on the application of close to reality procedures used in spectral-domain OCT scanners. It naturally generates images reproducing properties of real images in spectral-domain OCT, including the pixelized structure and finite depth of unambiguous imaging, influence of the optical spectrum shape, dependence on the optical wave frequency and coherence length, influence of the tissue straining, etc. Good agreement with generally accepted speckle features and properties of real OCT images is demonstrated.

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    7. A correlation-stability approach to elasticity mapping in optical coherence tomography

      A correlation-stability approach to elasticity mapping in optical coherence tomography

      A variant of compressional optical coherence elastography for mapping of the relative stiffness of biological tissues is reported. Unlike conventionally discussed displacement-based (DB) elastography, in which the decrease in the cross-correlation between subsequently obtained images is a negative factor causing errors in the mapping displacement and strain fields, we propose to intentionally use the difference in the correlation stability (CS) for deformed-tissue regions with different stiffnesses. We compare the parameter ranges (in terms of noise-to-signal ratio and strain) in which the conventional DB and CS approaches are operable. It is shown that the CS approach has advantages such as a ...

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    1-7 of 7
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    1. (6 articles) Institute of Applied Physics
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    3. (5 articles) Nizhny Novgorod State Medical Academy
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    5. (3 articles) Natalia D. Gladkova
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    A correlation-stability approach to elasticity mapping in optical coherence tomography A model for simulating speckle-pattern evolution based on close to reality procedures used inspectral-domain OCT Recent Trends in Multimodal Optical Coherence Tomography. II. The Correlation-Stability Approach in OCT Elastography and Methods for Visualization of Microcirculation Multimodal Optical Coherence Tomography in Visualization of Brain Tissue Structure at Glioblastoma (Experimental Study) The Development of the Methodology of Monitoring Experimental Tumors Using Multimodal Optical Coherence Tomography: the Choice of an Optimal Tumor Model In-vivo longitudinal imaging of microvascular changes in irradiated oral mucosa of radiotherapy cancer patients using optical coherence tomography Semi-analytical full-wave model for simulations of scans in optical coherence tomography with accounting for beam focusing and the motion of scatterers Optical Coherence Tomography Angiography in Myopic Patients Quantification of retinal microvasculature and neurodegeneration changes in branch retinal vein occlusion after resolution of cystoid macular edema on optical coherence tomography angiography Machining head for a laser machining device Quantitative Comparison Of Microvascular Metrics On Three Optical Coherence Tomography Angiography Devices In Chorioretinal Disease Detection of and validation of shadows in intravascular images