ABSTRACT
The endothelium is a tissue most vulnerable to the SARS-CoV-2 virus. Systemic endothelial dysfunction leads to the development of endothelitis which causes the main manifestations of the disease and systemic disturbance of microcirculation in various organs. Pulmonary microcirculatory damage, the most striking clinical manifestation, was the reason to perform SPECT to detect microcirculation disorders. Aim. To assess microcirculatory changes in the lungs of patients who had no previous respiratory diseases and had a COVID-19 infection at different times from the onset of the disease. Methods. SPECT data were analyzed in 136 patients who had a proven coronavirus infection of varying severity from May 2020 to June 2021. Results. All patients showed changes in microcirculation in the lungs in the post-COVID period. The severity of microcirculation disorders had a significant correlation (rs = 0.76;p = 0.01) with the degree of damage to the pulmonary parenchyma and an average correlation (rs = 0.48;p = 0.05) with the timing of the post-COVID period and the degree of residual lesions on CT (rs = 0.49;p = 0.01). The examined patients with persistent clinical complaints had pulmonary microcirculatory lesions, which may indicate the development of vasculitis, at all stages of the post-COVID period. Despite regression of the lesions confirmed by CT in 3 to 6 months after the acute COVID-19 infection, specialists from Russian and other countries report that 30–36% of patients develop pulmonary fibrosis. Similar changes were identified in 19.1% of the examined patients in our study. Conclusion. Microcirculation disorders are detected in all patients in the post-COVID period, irrespective of the severity according to CT. Progressive decrease in microcirculation in the lower parts of the lungs, local zones of hypoperfusion with the critically low accumulation of radiopharmaceuticals, persistent areas of compaction of the lung tissue (so-called “ground glass”), reticular changes, and the development of traction bronchiectasis, a decrease in the diffusion capacity of the lungs and alveolar volume may indicate fibrotic lesions with subsequent development of virus-associated interstitial lung disease. © 2021 Medical Education. All rights reserved.
ABSTRACT
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 <0.05, r = 0.76) on the degree of damage to the pulmonary parenchyma and an average correlation dependence (r = 0.51) on the timing of the postcoid period. Signs of PE / microthrombosis changes were significantly more frequent (p <0.05, r = 0.82) in patients with a more severe course of the disease. In patients with CLD, microcirculation decreased to critical levels, the overall level of decrease was up to 30% or more compared to the dock period (p = 0.034). The detection of small subsegmental level of triangular microcirculation defects, with partially restored blood flow, correlated to a high degree (r = 0.84) with an increase in the level of fibrinogen (4.6 + 1.8 mg / l) and indicated the consequences of PE, and an increase in the level of D-dimer (1750+ 215 ng / ml) with the presence of a triangular shape of defects in the accumulation of radiopharmaceuticals correlated to a high degree (r = 0.88) with PE. Conclusion. Disorders of microcirculation in the lungs persist for a long time. They are detected in patients, regardless of the severity of the course of the pathological process, they increase during a dynamic study in patients, the deficit of perfusion depends on the degree of damage to the pulmonary parenchyma. The SARS-CoV-2 virus has a detrimental effect on the state of blood circulation in patients with chronic lung diseases. In patients who have undergone COVID-19 with the development of thrombosis, signs of postponed pulmonary embolism are revealed and zones of local pneumosclerosis are formed. © 2021 Russian Electronic Journal of Radiology. All rights reserved.