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Introduction. The COVID-19 pandemic not only caused a surge of viral pneumonia patients, but also opened up new opportunities in the field of radiology. One of the conditional «pluses» was the quantitative damage assessment of the lung parenchyma and microcirculation in COVID-19 using an artificial intelligence program. Objective. To evaluate the AI capabilities to detect the severity of anatomical and microcirculatory post-inflammatory disorders by CT and SPECT of pneumonic patients data. Materials and Methods. We analyzed prospective and retrospective data obtained by radiological studies of 187 patients with community-acquired pneumonia from 2006 to 2022 in the clinics of the St. Petersburg State Medical University named after acad. I.P. Pavlov. The follow-up period varied from 3 months to 8 years. The mean age of the patients was 34.3±9.2 years (w/m – 107/80). All patients underwent CT scan, a comprehensive functional examination of external respiration (KFIVD), SPECT. Results. The community-acquired pneumonia before the COVID-19 pandemic was generally characterized by signs of exudative bronchiolitis/bronchopneumonia, infectious viral alveolitis and pleuropneumonia. The first two forms in contrast to pleuropneumonia were associated with microcirculation disturbances. Signs of lung damage in COVID-19 had staging pattern based on morphological changes: edema, reticulation (increased severity of edema, cellular infiltration, intraalveolar fibrin), organization=consolidation (cellular infiltration, intraalveolar fibrin, fibroblast proliferation). Residual anatomical changes were accompanied by clinical symptoms (shortness of breath of varying severity, dry cough, weakness, intoxication). Conclusions. Using the artificial intelligence for post-processor CT and SPECT image processing seems to be relevant to assess the postinflammatory anatomical and microcirculatory disorders severity. Experience accumulation in combined AI and radiological study of patients with community-acquired pneumonia is capable to quantify residual anatomical and microcirculatory changes and useful for treatment tactics.

Introduction. Nowadays post-COVID respiratory symptoms that could be associated with pulmonary fibrosis progression are of concern. Objective. To compare CT and SPECT data of patients with post-COVID pulmonary fibrosis, and to define whether the lung fibrosis progression could be predictable. Material and Methods. Changes in chest CT scan, microcirculation disorders (SPECT) and impaired lung function parameters (DLCO) were analyzed in 74 post-COVID patients with residual consequences of COVID-19. Results. A year or more after the disease, 17 % of patients had isolated ground-glass areas, 24 % of patients had ventilation mosaics and air traps, most patients had compaction of the interlobular interstitial tissue of a short UIP type (67 %); consolidation zones (38 %); zones of pulmonary fibrosis of different lengths (57 %); discoid atelectasis (39 %); bronchiectasis (26 %), pulmonary hypertension (PH) (36 %). Significant decrease of the diffusion capacity and great microcirculation disorders accompanied by more than 50 % perfusion lack were detected. We demonstrated that significant radiological and functional effects of viral pneumonia were likely to be associated with post-viral interstitial lung disease. Conclusions. 1. Complete X-ray examination with lung diffusion capacity determination can contribute to optimal dispensary observation of post-COVID patients. 2. Microcirculation disorder greater than 50 % of the norm is a predictor of the lung parenchyma changes and can contribute to the prediction of long-term effects of the disease. 3. Complete radiation monitoring is required for patients over 60 years of age; post-COVID patients having severe form of the disease; patients having respiratory complaints for more than a year, regardless of the severity of COVID-19.

Introduction. The most striking manifestations of the disease caused by the SARS-CoV-2 virus are manifested in the microvasculature of the lungs. The study of the residual manifestations of the disease seems to be relevant, since it can affect the development of complications and its outcome.Purpose of the work. To assess changes in the microvasculature of the lungs of patients who have undergone COVID infection at different times from the onset of the disease, and who have not previously had respiratory diseases.Material and methods. SPECT data were analyzed in 96 patients with proven coronavirus infection from May 2020 to April 2021 of varying severity. The results of SPECT, MSCT, FVD and coagulation hemostasis (D-dimer, fibrinogen, prothrombin index) were compared.Results. All patients were found to have changes in microcirculation in the lungs in the postcoid period. The severity of microcirculation disorders had a significant dependence (pConclusion. Disorders of microcirculation in the lungs are detected in patients, regardless of the severity of the pathological process. The method of automatic processing of the results of radiological studies of the lungs in comparison with the norm made it possible to quantitatively assess the degree of changes in microcirculation after pneumonia caused by the SARS-CoV-2 virus.

Introduction. The possible formation of persistent residual changes in the lung after a COVID-19 began to be reported after the first wave of the pandemic, but their extent and prevalence have not been fully assessed.Purpose of the study. Evaluate CT patterns of residual changes in COVID-19 lung lesions. Materials and methods. We analyzed the clinical and radiation data of 868 patients (f/m — 441/427) who underwent COVID-19 and were observed in the clinics of First St.-Petersburg State Medical University n.a. academician I. P. Pavlov since 2020 until 2021. The average age of the patients was 33,4±17,2 years. All patients underwent high-resolution computed tomography in dynamics — after 6 months or more. Statistical data processing was performed using the Statistika 16.0 software/statistical package.Results. Analysis of the results of CT examination revealed the following patterns of residual changes after a new coronavirus infection: ILAs (interstitial lung abnormalities) in 0,7%, the formation of fibrotic changes (NsIP, OIP) in 0,2% of patients, CT signs of constrictive bronchiolitis in 0,3% of patients, CT signs of persistence in 0,1% of patients, CT signs of the formation of pulmonary hypertension, identified in 0.3% of patients.Conclusions. CT allows to identify a variety of residual changes in COVID-19 lung lesions, which is important for assessing the prognosis of the disease and the tactics of its treatment.

Сonsidering the influence of the SARS-CoV-2 virus on the pulmonary vascular system, manifested by the development of endotheliitis, vasculitis, thrombosis and coagulopathies, one of the leading directions of radiological examination may be the study of microcirculation by SPECT. Purpose. To assess changes in the microvasculature of the lungs of patients who have undergone COVID infection at different times from the onset of the disease. Material and methods. SPECT data were analyzed in 170 patients with previous coronavirus infection from May 2020 to June 2021 of varying severity. The results of SPECT, MSCT, FVD and coagulation hemostasis (D-dimer, fibrinogen) were compared. Results. All patients were found to have changes in microcirculation in the lungs in the postcoid period. The severity of microcirculation disorders had a significant dependence (p

The paper presents the results of modeling the distribution of bioimpedance in breast tissue with the aim of exploring the possibilities of mammographic examination to detect neoplasms and to solve the problems of personalized medicine. A three‑dimensional electrodynamic model of breast tissue with skin and neoplasm is considered. The model allows you to determine the spatial location of neoplasms depending on their size, depth at different thicknesses of the skin at given values of the detecting sensitivity of the mammograph. The results of modeling the spatial location of neoplasms are confirmed by experimental data and bioimpedance studies of patients. The experiment was carried out on a breast tissue simulator based on agar‑agar with imitation of neoplasm due to the introduction of a syringe injection of saline.

The effect of severe plastic deformation and the subsequent impact of high hydrostatic pressure on the elastic and microplastic properties of Cu–0.2 wt % Zr alloy has been studied and analyzed. The influence of nanoporosity, which is formed in the process of equal-channel angular pressing and is fixed by applying hydrostatic pressure, has been evaluated.

It is established that increases in nanoporosity and the proportion of high-angle grain boundaries in the process of equal-channel angular pressing are the main structural factors leading to reduction in mechanical stability (durability) of microcrystalline titanium during long-term tests under creeping conditions.

Special features of formation and propagation of microscopic cracks and pores in metals and alloys are considered and analyzed depending on the conditions of their formation. The effect of curing of microscopic discontinuities on mechanical properties, and especially on the endurance, is studied in tests performed under conditions of creep or cyclic loading.

Magnetic and structural properties of an amorphous alloy based on iron are investigated. The properties and state of the alloy are changed under hydrostatic pressure of up to 1.3 GPa. An increase in the pressure leads to a linear increase in the maximum magnetic induction and a linear decrease in the remanence. Two nanopore fractions with average sizes of ∼20 and 150 nm are revealed in the alloy with the use of small-angle x-ray diffraction. The application of the pressure decreases the size of nanopores and increases the average distance between their boundaries, i.e., increases the average sizes of continuity regions in the alloy. It is established that the relative change in the magnetic characteristics is linearly related to the change in the size of the continuity regions in the alloy. Upon extrapolation to zero nanoporosity, the remanence reduces to zero. The inference is made that the nanopores play a dominant role (as compared to other structural defects) in the magnetic properties of the alloy.

Rupture strength of the amorphous alloy based on nickel (Ni >80 ) has been measured in the temperature region 293–650 K under loading with a rate of 25 MPa/s. The samples in the form of 60–70 μm bands were prepared by spinning and were stabilized by temperature and force treatments, the amorphous state being preserved. The observed linear decrease in the rupture strength with increasing test temperature was analyzed in the framework of the kinetic thermal fluctuation theory of fracture. The initial barrier for elementary events of fracture of the alloy (activation energy), coefficients of local overstresses in the samples, and the theoretical strength of the alloy has been found.

The stressed state of nonlinearly elastic bodies in the vicinity of spherical and elliptical pores is considered. The development of plastic regions near such pores is analyzed. Calculations are compared with the experimental data on pore healing under hydrostatic pressure.