[Chest CT findings and their dynamic changes in patients with COVID-19].

Objective To define chest CT findings and their dynamic changes in patients with coronavirus disease 2019 (COVID-19) from disease onset to the cure. Method We analyzed the clinical and chest CT data of 6 patients with RT-PCR-confirmed COVID-19. According to the time from the disease onset to the cure or from the onset to each CT scan, the total of 30 chest CT scans were divided into 4 stages, namely stage 1 (0-4 days), stage 2 (5-9 days), stage 3 (10-14 days), and stage 4 (over 14 days). A semi-quantitative scoring system was used to quantitatively assess the pulmonary involvement on the basis of the involved area. The differences in chest CT signs and the lung injury scores based on CT findings were compared among the 4 stages. Results In stage 1, ground-glass opacities (GGO) was found frequently in the subpleura, and the CT score was the lowest at 4.00±0.40. Stage 2 was characterized by an increased and mixed density (crazy-paving pattern) with mild consolidation of the lungs, and the CT score reached its peak level of 7.38±3.34 ( P < 0.05). In stage 3, an expanded range of consolidation and linear lesions were found in the lungs, and the total CT score averaged 6.86±2.91. In stage 4, a gradual resolution of the consolidation occurred with more linear lesions in the lungs, and the total CT score was 6.21±1.56. The CT scores of the lower lobes were significantly higher compared with those of the middle/upper lobes ( P < 0.05) in stage 3 and stage 4. Conclusion Chest CT scans allows dynamic monitoring of the changes in the distribution, density and extent of the pulmonary lesions in the 4 stages, which are closely correlated with the evolution of the disease course of COVID-19.