The article is a systematic review of the literature data summarizes to date on the issue of COVID-19-associated anosmia. We mainly used full-text and abstract electronic databases (PubMed, Scopus and Web of Science). The paper discusses hypothetical mechanisms of development, clinical features, as well as methods of diagnosis and treatment of COVID-19-associated anosmia.

We report on performance of PDT assisted by optical monitoring techniques: dual-wavelength fluorescence imaging and optical coherence tomography. Both techniques provide complementary information of PS distribution and photobleaching and tissue reaction to PDT. The proposed approach allowed to perform a comparative analysis of different PDT regimens in animal study and develop an improved protocol for PDT of basal cell carcinoma.

Chronic Rhinitis (HR) is a common inflammatory disease that significantly affects the quality of life. Differential diagnostics of various forms of CV is complicated by the lack of objective safe methods based on morphological verification. The aim of our study was to show the possibility of optical coherence tomography (OCT) for differential diagnosis of various forms of chronic rhinitis (HR). The research was carried out on the basis of ENT clinic of SBUZ N.A. Semashko NSDC, N.Novgorod. With the help of OCT 51 patients aged 32 to 74 years were examined. The method of classification of diagnostic images of the nasal mucosa based on the approxima­ tion of the histogram of the image by the analytical function is proposed. It is shown that optical coherence tomography is capable of non­invasive real­time detection of morphofunctional features of the nasal cavity mucosa in normal and various inflammatory pathol­ Оригинальные статьи Original investigations

Progress in photodynamic therapy (PDT) requires development of novel protocols. We report on performance of PDT employing chlorine-based photosensitizers and irradiation at wavelengths of 405 and 660 nm with monitoring by fluorescence imaging (FI) and optical coherence tomography (OCT). The study includes numerical simulations, model and animal experiments, as well as clinical monitoring.

The aim of the study is to develop approaches for fluorescence monitoring and planning of photodynamic therapy employing chlorine series photosensitizers. Materials and Methods. The study included numerical simulations and experiments with optical agar phantoms of biotissue and human skin in vivo. Fluorescence imaging was used as a method of optical monitoring. Chlorine series photosensitizer Photoditazin (Veta Grand, Russia) was employed. Numerical simulation of light propagation was performed with Monte-Carlo technique for a multilayer skin model. Results. It was demonstrated that in the case of two-wavelength fluorescence monitoring of photosensitizer penetration into the tissue the ratio of fluorescence signals excited at wavelengths of 405 and 660 nm can be used as a characteristic of photosensitizer penetration depth in biological tissue. The results of numerical simulations are in good agreement with the results of model experiments on agar phantoms and pilot in vivo experiment. Radiant exposure and absorbed light dose maps at the wavelengths of 405 and 660 nm were calculated employing Monte-Carlo technique; the dependencies of the characteristic dose values on the optical properties of the medium were analyzed. Conclusion. Two-wave fluorescence imaging technique allows for non-invasive estimation of chlorine series photosensitizer penetration depth into the biotissue after topical application, while numerical simulation by Monte-Carlo method allows for more accurate choice of the light exposure dose for photodynamic therapy depending on optical properties of the tissue and the radiation wavelength.

Introduction: The distinctive features of modern inflammatory diseases are their indolent course and predisposition to chronicity. Chronic inflammation is the basis for the development of serious disorders, including autoimmune and oncologic ones, and a cause of major functional abnormalities of the human body. Diagnostics of chronic inflammation is associated with a number of problems which originate from a variety of clinical phenotypes and morphological forms, on the one hand, and from the rising prevalence of their latent course, on the other. In its turn, an adequate treatment choice may be based on understanding and accurate detection of etiological and morphological types of the disease. In this connection, development of novel diagnostic techniques, such as optical coherence tomography (OCT), is of utmost importance. Aim: To demonstrate feasibility of OCT in detection of morphological abnormalities associated with chronic inflammatory disorders of various localizations. Materials and methods: OCT diagnostics was performed in addition to standard diagnostic procedures in 225 patients with chronic inflammatory disorders of various localizations, such as chronic recurrent rhinitis, chronic latent salpingitis and chronic endometritis. For OCT, an “OCT-1300U” system was used, with central wavelength of 1280 nm, spatial resolution of 15–20 μm, image acquisition rate of 8 frames per second, imaging depth of 1.4 mm and a probe diameter of 2.4 mm. The following techniques of quantitative processing were used for processing of the OCT images. Quantitative characterization of histograms and image texture was performed with further determination of values typical for various images groups corresponding to particular states of biological tissues. Neural network was also employed with histograms and 2D Fourier transforms of the images as input data. Results: OCT laparoscopy allowed to obtain three types of OCT images of fallopian tubes with features typical for healthy and inflammatory states. Presence of heterogeneity in the structure of an OCT image indicated heterogeneity in the muscle layer of the fallopian tube, which allowed for a conclusion on chronic salpingitis. With OCT hysteroscopy we demonstrated the ability of OCT to visualize pathomorphologic features of chronic endometritis. The diagnostic data obtained by OCT-rhinoscopy allowed to draw preliminary conclusions on the OCT ability to detect specific features of various types of chronic rhinitis. Numerical processing of diagnostic OCT images resulted in their higher objectivity and an improvement of diagnostic accuracy of the technique. Conclusion: OCT is able to detect morphological changes induced by a chronic inflammatory process. OCT criteria were shown to be universal for various organs. We demonstrated the possibility of non-invasive diagnostics of pathomorphologic forms of disease, showed some challenges in the development of OCT for diagnostics of non-tumor disorders and ways to overcome them are proposed, in particular, the use of image numerical processing. Further studies seem to be justified.