Comprehensive evaluation of the lesion on the first positive CT of patients with COVID-19 pneumonia

Abstract

Aims and objective: To analyse the high-resolution computed tomography (HRCT) early imaging features and the changing trend of coronavirus disease 2019 (COVID-19) pneumonia. Materials and Methods: A retrospective study was conducted in the Department of Radiology in Sadar Hospital, Aurangabad, Bihar, India and Netaji Subhas Medical College and hospital, Amhara, Bihta, Patna, Bihar. Total 50 patients with COVID-19 pneumonia who had an isolated lesion on the first positive CT were included in this study. The recorde for each lesion: sites, sizes, location (peripheral or central), attenuation (ground-glass opacity or consolidation), and other abnormalities (supply pulmonary artery dilation, air bronchogram, interstitial thickening, etc.) were studied. The follow-up CT images were compared with the previous CT scans, and the development of the lesions was evaluated. Results: The average age of the 32 male and 18female patients was 41.25 ± 11.03 years. The most common symptom was fever 44%, followed by Cough 36%, Myalgia 18% Fatigue 14%, Vomiting/Diarrhea 4%, Headache, Muscle pain, Abdominal pain. The affected segments were located in the lower lobes 56% and in the right lobe were involved more than left. .A higher proportion of medium lesions (diameter, 1 to < 3 cm) was noted 64 % and 6% had sizes less than 10 mm 12 % and 24% had size ≥3 cm. The lesions tended to be peripheral 66 % and subpleural 82 % on the first positive chest CT. 16% lesions had interlobar pleural locations and had no peripheral distribution, and 28 % of isolated lesions were located in the central region. No pure solid nodule with a well-defined boundary was observed. The main chest CT findings were pure ground glass opacity (GGO) 42%, and mixed GGO lesions with consolidations 58 %. A halo sign of ground glass around a solid nodule was observed in 12 of 50 patients (24 %). Supply pulmonary artery dilation was found in 47 of 50 patients (94%) and air bronchogram was observed in 34 of 50 patients (68%). Other findings included the thickening of intralobular interstitium 26% and interlobular septa 2%. Pleural effusion was noted in only 1 of 50 patients (2 %). Conclusion: The typical early CT features of COVID-19 pneumonia are ground-glass opacity, and located peripheral or subpleural location, and with supply pulmonary artery dilation. Reticulation was evident after the 2nd week and persisted in half of patients evaluated in 4 weeks after the onset. Long-term follow-up is required to determine whether the reticulation represents irreversible fibrosis.

Keywords: CT features, CT images, COVID.