BACKGROUND. At present radiological criteria for diagnosis of viral pneumonia associated with SARS-CoV-2 have been defined. However, with the further course of the pandemic, physicians began to observe more and more often destructive processes developing in the lungs of patients with non-hospital pneumonia of viral etiology (COVID-19). Due to the development of surgical complications (pneumothorax, pneumomediastinum, vanishing lung syndrome) the question of their differential diagnostics with purulent-destructive lung diseases became actual. OBJECTIVE. To show the possibilities of differential diagnostics of infectious lung destruction (ILD) with cyst-like changes in the lungs at COVID-19 using clinical examples and data of computed tomography (CT) scan of the chest and pathomorphological study. MATERIALS AND METHODS. CT of the patients with ILD (lung abscess) and 90 patients with non-hospital pneumonia of viral etiology (COVID-19), who were treated in the National Institute of Phthisiology and Pulmonology named after F.G. Yanovsky of the NAMS of Ukraine were analyzed. RESULTS AND DISCUSSION. There were analyzed 90 CT scans of the whole body of patients with non-hospital pneumonia of viral etiology (COVID-19); among them 27 cases (15 male and 12 female, aged from 23 to 78 years) with radiological signs of vanishing lung syndrome were revealed, which made 30 % of all patients with a complicated course of the disease. Chest CT findings and pathomorphologic findings in cyst-like changes in patients with COVID-19 were compared with those in patients treated for lung abscess. CONCLUSIONS. Clinical picture, pathogenesis and pathomorphological changes of pulmonary parenchyma at ILD differ greatly from non-hospital pneumonia of viral etiology (COVID-19) and form specific changes, which are revealed by chest CT. Necessary development of indications for surgical treatment in vanishing lung syndrome which occurs in patients with complicated course of COVID-19.

BACKGROUND. The mechanism of development of post-COVID syndrome is not fully understood. Long-term retention of complaints in patients is associated with long-term persistence of the virus, hyperinflammatory response of the body, as well as with the peculiarities of the patient’s cellular and humoral immunity. Secondary infectious complications in the post-COVID period are due not only to the ability of the SARS-CoV-2 virus to damage erythrocytes and attack the red bone marrow in the acute phase of the disease. It has been proven that the SARS-CoV-2 virus leads to the disappearance of white pulp cells in the spleen, the tissue where cells of the immune response, in particular T- and B-lymphocytes responsible for infectious immunity, mature. OBJECTIVE. To investigate the frequency of secondary infectious complications of the respiratory tract and lungs in patients with post-COVID syndrome who underwent inpatient treatment. MATERIALS AND METHODS. Clinical, laboratory and radiological data of 90 patients with post-COVID syndrome who were undergoing inpatient treatment in the clinical departments of the SI “National institute of phthisiology and pulmonology named after F.G. Yanovsky of the NAMS of Ukraine”. The diagnosis of coronavirus disease (COVID-19) was established in accordance with the current national protocol for the treatment. Computed tomography (CT) of the chest organs was performed on the Aquilion TSX-101A scanner (Toshiba, Japan). RESULTS AND DISCUSSION. Complications of COVID-19 were determined according to the clinical and functional, laboratory examination and CT scan of the chest. Some patients had two or more complications at the same time. Patients with post-COVID syndrome were most often hospitalized for progression or slight positive dynamics of the pathological process of the respiratory tract and lungs, disappearing lung syndrome, fibrotic changes in the lungs, exacerbation of bronchoobstructive lung diseases and infectious complications. The latter were observed most often – in 53,3 % of patients. Fungal and bacterial complications occurred secondarily, mainly in patients with disappearing lung syndrome, in places where cystlike cavities were formed. The most common concomitant diseases in patients with post-COVID syndrome were cardiovascular diseases and diabetes. CONCLUSIONS. The proportion of infectious complications of the respiratory tract and lungs in patients with post-COVID syndrome, who are indicated for inpatient treatment in the pulmonology department, is 53.3 %. The most frequent causes of infectious complications of the respiratory tract and lungs in patients with post-COVID syndrome are the reactivation of the Epstein – Barr virus infection – in 30.0 %, which in 2.2 % of patients is combined with the reactivation of the hepatitis C virus, and bacterial infections – in 15.6 %. Aspergillosis and mucormycosis occur in 1.1 and 3.3 % of patients respectively.

Objective — to study the dynamics of pathological changes of lungs in patients with a long course of viral pneumonia of COVID-19 by the analysis of data of a computer tomography (CT) of thoracic organs (ТО). Materials and methods. Analyzed in the dynamics of CT of TO patients with changes in the lungs with a long course of community-acquired viral pneumonia COVID-19. Patients were examined at the SI «National Institute of Tuberculosis and Pulmonology F.G. Yanovsky NAMS of Ukraine» (NIFP NAMS) on the CT scanner Aquilion TSX-101A «Tochiba» (Japan), as well as analyzed the archival data of the CT TO.The diagnosis of COVID-19 was established in accordance with the current protocols for the treatment of coronavirus disease «Provision of medical care for the treatment of coronavirus disease (COVID-19)», approved by the Order of the Ministry of Health of Ukraine dated April 2, 2020 N 762 ). Results and discussion. CT of TO was analyzed in 120 patients with community-acquired pneumonia of viral etiology (COVID-19), who were examined at various intervals for 6—12 months. It was found that in 30 patients (19 men and 11 women aged 24 to 72 years) with long-term pneumonia (COVID-19), there are significant structural changes in the lung parenchyma that are diagnosed on CT of TO.The ways of regression of the detected changes, as a result of which there is a resorption of pathological changes or the development of «disappearing lung syndrome», requires differential diagnosis and dynamic monitoring with densitometric studies using CT of TO. Clinical cases are given. The first case shows how after a mild acute period of COVID-19, developed more severe Long COVID with a long course of community-acquired viral pneumonia COVID-19. On the first CT of TO «fibrotic-like changes» were revealed, but at the subsequent monitoring (within 8 months) against the background of the carried-out pathogenetic treatment, there was a full restoration of pneumatization of a pulmonary parenchyma without formation of fibrosis. The second case demonstrates how after a severe course of acute COVID-19, developed Long COVID with a long course of community-acquired viral pneumonia COVID-19. The second case demonstrates how after a severe course of acute COVID-19, developed Long COVID with a long course of community-acquired viral pneumonia COVID-19. CT of TO after the acute period of the disease revealed changes that during monitoring (for 7 months) despite the treatment, led to the development of degenerative-destructive changes in the lungs and continue to progress. Conclusions. In patients with Long COVID -19 it is advisable to monitor CT of TO. The frequency of the study should be decided personally, taking into account the clinical course of the disease. Due to the high rate of degenerative pulmonary parenchymal COVID-19 viral pneumonia in patients with long-term nosocomial viral pneumonia, new methods of treating patients with «disappearing lung syndrome» need to be developed.

For 3 years since the announcement of the coronavirus disease (COVID-19) pandemic, doctors around the world have been studying the complications caused by different strains of SARS-CoV-2. To study the structure of the lung parenchyma in patients with a complicated course of community acquired viral pneumonia of COVID-19 and different ways of transformation, the most informative is the digital software processing of computed tomography (CT) images of the chest organs (CT). Objective — to investigate the ways of transformation of typical radiological signs in patients with community-acquired pneumonia of viral etiology (COVID-19) and the possibility of their transformation into bronchioloalveolar cancer (BAC) by the radiomics method. Materials and methods. Chest CT data in the dynamics of 112 patients with a complicated course of community-acquired viral pneumonia COVID-19 were analyzed. Chest CT was performed on an Aquilion TSX-101A Tochiba scanner (Japan) with subsequent digital software processing of CT images using the Dragonfly program from Obyect Research Systems (ORS), Montreal, Canada. The diagnosis of BAC was made based on the data of the pathomorphological examination. Transbronchial biopsy of lung tissue was performed during diagnostic fibrobronchoscopy. Results and discussion. As a result of the analysis of possible ways of transformation of typical X-ray changes of COVID-19 community-acquired pneumonia, we identified 3 main ways. In 71 (64.0 %) subjects, according to the chest CT scan, there was gradual resorption of pathological changes and recovery of the lung parenchyma. In 35 (31.2 %) patients, the formation of signs of «vanishing lung syndrome» was detected. 5 (4.5 %) patients were diagnosed with BAC according to the CT scan and pathomorphological examination. Digital software processing of chest CT in dynamics allows to track the process of transformation of the lung parenchyma structure in patients with a complicated course of COVID-19 community-acquired viral pneumonia into BAC and in some cases to confirm the secondary nature of the oncological process. Conclusions. Digital software processing of the chest CT data is a highly informative research method that clearly reflects the morphological structure of the lung parenchyma and allows diagnosis and differential diagnosis of diseases.

The article shows the possibility of applying radiomics in the processing of chest CT data in the diagnosis of pulmonary tuberculosis. Currently, a subjective method based on the knowledge and experience of a radiologist is used to process CT images. A new approach to CT image analysis can fundamentally change the diagnostic process. Its essence is to create mathematical models and computer algorithms that take medical images as input and produce pathophysiological features of tissues.Dragonfly software, provided free of charge by OBYECT RESERCH SYSTEMS (ORS), Montreal, Canada, is used for CT slice analysis, which enables segmentation, mathematical and statistical processing of images, construction of ordinary and segmented histograms. To work with the program, dicom - CT files are transformed into raster files (Tiff, Jpeg, Raw) and further analysis of CT slices is performed by grayscale gradations (behind image pixels, not behind dicom file voxels). It should be emphasized that the grayscale analysis correlates with the Hounsfield units.It has been shown that based on the data of pathomorphological examination of the affected tissue, it is impossible to determine the difference between chemoresistant and susceptible pulmonary tuberculosis.Processing of CT data with the construction of conventional and segmental histograms using Dragonfly software tools makes it possible to identify pathophysiological features of tissues in the diagnosis of sensitive and chemoresistant pulmonary tuberculosis. Further research is needed to identify patterns and differences in the determination of densities in the diagnosis of sensitive and chemoresistant pulmonary tuberculosis.