V.Yu. Zaitsev

Russian Academy of Sciences | RAS · Institute of Applied Physics

(1) Introduction. The problem that limits the intraoperative use of OCTA for the intestinal circulation diagnostics is the low informative value of OCTA images containing too many motion artifacts. The aim of this study is to evaluate the efficiency and safety of the developed unit for the prevention of the appearance of motion artifacts in the OCT...

In this work, we use the method of optical coherence elastography (OCE) to enable quantitative, spatially resolved visualization of diffusion-associated deformations in the areas of maximum concentration gradients during diffusion of hyperosmotic substances in cartilaginous tissue and polyacrylamide gels. At high concentration gradients, alternatin...

Early stages of pelvic organ prolapses are mainly associated with the pelvic floor disfunction as a result of elasticity changes in the connective tissues including the vaginal wall. In this study, for the first time we used a compression optical coherence elastography (C-OCE) method for assessing elasticity of the vaginal wall under prolapse condi...

The recent impressive progress in Compression Optical Coherence Elastography (C‐OCE) demonstrated diverse biomedical applications, comprising ophthalmology, oncology, etc. High resolution of C‐OCE enables spatially‐resolved characterization of elasticity of rather thin (thickness <1 mm) samples, which previously was impossible. Besides Young's modu...

Displacement tracking is an important step in realization of compression optical coherence elastography (C-OCE), especially in the context of obtaining nonlinear stress-strain dependences and subsequent evaluation of the tissue Young’s modulus. The rapidly progressing phase-sensitive C-OCE, however, enables direct measurements of only rather small...

In this paper, we present a new approach to contrast-agent-free angiographic visualization in optical coherence tomography (OCT). The proposed approach has much in common with imaging of local interframe strains in OCT-based elastography and utilizes the fact that the interframe motion of blood particles leads to discontinuity of strains within the...

Soft biological tissues, breast cancer tissues in particular, often manifest pronounced nonlinear elasticity, i.e., strong dependence of their Young’s modulus on the applied stress. We showed that compression optical coherence elastography (C-OCE) is a promising tool enabling the evaluation of nonlinear properties in addition to the conventionally...

We present in this study optical coherence tomography angiography (OCTA) and OCT attenuation imaging (OCTAI) for in vivo non-destructive visualization of intramural blood and lymphatic vessels of the intestine wall. Rabbit small intestine in the norm and after thoracolumbar sympathectomy served as the object of the intraoperative study. Compared to...

The aim of the study. We compare the effectiveness of multimodal optical coherence tomography (MM OCT) in the traditional structural OCT mode and the OCT elastography (OCE) mode in addressing two clinically important tasks: (1) detecting groups of tumor cells at surgical margins during breast-сonserving surgery (BСS) in breast cancer (BC) and (2) i...

The aims of this study are (i) to compare ultrasound strain elastography (US-SE) and compression optical coherence elastography (C-OCE) in characterization of elastically linear phantoms, (ii) to evaluate factors that can cause discrepancy between the results of the two elastographic techniques in application to real tissues, and (iii) to compare t...

This paper presents a recently developed variant of phase-resolved Optical Coherence Elastography (OCE) enabling non-contact visualization of transient local strains of various origins in biological tissues and other materials. In this work, we demonstrate the possibilities of this new technique for studying dynamics of osmotically-induced strains...

Fracture geometry, density, and distribution control fluid and thermal transport in low porosity rocks, as well as their seismic attributes. The creation of cracks throughout the matrix can result in large and disparate reductions in P and S wave velocities with negligible porosity development, which breaks the classic velocity‐porosity relationshi...

We present a real-time realization of OCT-based elastographic mapping local strains and distribution of the Young’s modulus in biological tissues, which is in high demand for biomedical usage. The described variant exploits the principle of Compression Optical Coherence Elastography (C-OCE) and uses processing of phase-sensitive OCT signals. The st...

The microstructure-sensitive acoustic parameters (MSA parameters) of metal of the object under control are determined using measurements of the propagation time of bulk elastic waves of the ultrasonic range by the echo-pulse method. The structural features of the metal are thus evaluated not only in the surface layer, but also throughout the entire...

We present a computationally highly efficient full-wave spectral model of OCT-scan formation with the following features: allowance of arbitrary phase-amplitude profile of illuminating beams; absence of paraxial approximation; utilization of broadly used approximation of ballistic scattering by discrete scatterers without limitations on their densi...

We present a computationally efficient full-wave spectral model of OCT-scan formation with the following capabilities/features: (i) the illuminating beam may have arbitrary phase-amplitude profile with allowance of a sharp diaphragm; (ii) paraxial approximation that limits the degree of focusing/divergence is not used; (iii) the broadly used approx...

A computationally efficient and fairly realistic model of OCT-scan formation in spectral-domain optical coherence tomography is described. The model is based on the approximation of discrete scatterers and ballistic character of scattering, these approximations being widely used in literature. An important feature of the model is its ability to eas...

In this paper, we propose a non-destructive acoustic method for assessing microstructural alterations produced in metals as a result of processing and exploitation damage. The method is based on measuring ratios of longitudinal and shear ultrasound waves velocities with subsequent normalization of these ratios to their counterparts corresponding to...

The possibility to assess molecular-biological and morphological features of particular breast cancer types can improve the precision of resection margin detection and enable accurate determining of the tumor aggressiveness, which is important for treatment selection. To enable reliable differentiation of breast-cancer subtypes and evaluation of re...

In this paper, we present a computationally highly efficient full-wave model of optical coherence tomography (OCT)-scan formation by focused beams in spectral-domain OCT. Similarly to some previous models, it is based on the summation of fields scattered by discrete sub-resolution scatterers, and enables one to account for the axial and lateral inh...

In this chapter we consider applications of multimodal OCT for characterizing tumorous tissues. Namely, the following extensions of OCT are discussed: (1) polarization-sensitive OCT providing complementary images in the initial and cross-polarization channels (CP OCT), (2) OCT-based label-free angiography (OCA), and (3) compressional variant of OCT...

In this study, for the first time, we apply optical coherence elastography to map and monitor slow strains caused by residual stresses in cartilaginous tissues subjected to thermomechanical laser-assisted reshaping in regimes used for the preparation of implants in otolaringological surgery. Such laser-fabricated implants made of the patient's rib...

Quantitative mapping of deformation and elasticity in optical coherence tomography has attracted much attention of researchers during the last two decades. However, despite intense effort it took ~15 years to demonstrate optical coherence elastography (OCE) as a practically useful technique. Similarly to medical ultrasound, where elastography was f...

A new computational setup suitable for the exploration of nonlinear effects in free propagation and dissipation of surface acoustic waves (SAWs) is developed based on the molecular dynamics (MD) simulation method. First applications of the computational model demonstrate the ability of atomistic simulations to reproduce the key features of the nonl...

We present a non-invasive (albeit contact) method based on Optical Coherence Elastography (OCE) enabling the in vivo segmentation of morphological tissue constituents, in particular, monitoring of morphological alterations during both tumor development and its response to therapies. The method uses compressional OCE to reconstruct tissue stiffness...

Pronounced elastic nonlinearity intrinsic to many biological tissues makes the Young's modulus (stiffness) of the tissue strongly dependent on the current strain and stress. The measured modulus may vary several times for rather moderate tissue straining within a few per cent, such strains being quite typical for compressional optical coherence ela...

A computationally highly efficient full-wave model of OCT-scan formation by focused beams in spectral-domain optical coherence tomography (OCT) is presented. Similarly to some previous models, it is based on summation of fields scattered by discrete sub-resolution scatterers and enables accounting for axial and lateral inhomogeneity of the illumina...

Emerging methods of anti-tumor therapies require new approaches to tumor response evaluation, especially enabling label-free diagnostics and in vivo utilization. Here, to assess the tumor early reaction and predict its long-term response, for the first time we apply in combination the recently developed OCT extensions - optical coherence angiograph...

We present a non-invasive method based on Optical Coherence Elastography (OCE) enabling the in vivo segmentation of morphological tissue constituents, in particular, monitoring of morphological alterations during both tumor development and its response to therapies. The method uses compressional OCE to reconstruct tissue stiffness map as the first...

Microvascular networks of human basal cell carcinomas (BCC) and surrounding skin were assessed with optical coherence angiography (OCA) in conjunction with photodynamic therapy (PDT). OCA images were collected and analyzed in 31 lesions pre-treatment, and immediately/24 hours/3–12 months post-treatment. Pre-treatment OCA enabled differentiation bet...

Moderate heating of collagenous tissues such as cartilage and cornea by infrared laser irradiation can produce biologically non‐destructive structural rearrangements and relaxation of internal stresses resulting in the tissue reshaping. The reshaping results and eventual changes in optical and biological properties of the tissue strongly depend on...

Analysis of semi-transparent low scattering biological structures in optical coherence tomography (OCT) has been actively pursued in the context of lymphatic imaging, with most approaches relying on the relative absence of signal as a means of detection. Here we present an alternate methodology based on spatial speckle statistics, utilizing the sim...