Abstract

Introduction: The COVID-19 pandemic is a global situation has triggered a public health emergency and severe social, economic disruption around the world. It is necessary to longterm follow up for detecting sequelae in the post - Covid period. In Vietnam, there is a lack of studies aboutthe imaging of post COVID-19 stage.

Purpose: To characterize patterns and frequencies of chest CT abnormalities 12 months after COVID-19 pneumonia; and determine the association betweenclinical symptoms, D-dimervalue and pulmonary abnormalities on chest CT scan.

Materials and Methods: Case series study. Severe COVID-19 pneumonia patientshad treated at Trung Vuong Hospital between June 01, 2021 to October 31, 2021; agreed to receive the follow - up tests after 12 months. A semi - quantitative scoring system was used to quantitatively estimate the pulmonary involvement of all these abnormalities on the basis of the area involved; each of the 5 lung lobes was visually scored from 0 to 5; the total CT score was the sum of the individual lobar scores and ranged from 0 to 25.

Results: 62 participants (mean age 51,82; 29 male) were assessed. In 56 of 62 (90%) participants, CT abnormalities were observed: ground - glass opacification 74,19%; parenchymal band 70,96%; reticular pattern 33,87%; subpleural curvilinear 12,9%; emphysema 9,67%; bronchodilation 4,83%, nodular 4,83%; consolidation 3,22%. The rate of ground - glass opacification in female wassignificantly higher than in male. There was an association between cough and ground - glass opacification. The CT score of the lower lobes was significantly higher than the others. The D-dimer value in patients with abnormal chest CT (n = 56) was higher than patients with normal chest CT (n = 6); however, the difference is not statistically significant.

Conclusion: CT abnormalities were remained at 12 months after COVID-19 pneumonia. Ground - glass opacification and parenchymal band account for the highest percentage. Lesions were distributed mainly in the lower lobes. Female, cough were associated with ground - glass opacification.