Series CT scans in an 85-year-old man with COVID-19 pneumonia in the severe group. (a) Scan obtained on disease day 4, showing patchy ground-glass opacities plus interlobular septal thickening (crazy paving). The Predominant CT pattern was of GGO type, with 12 as total CT score. (b, d) Scan obtained on day 10, the disease progressed rapidly to ARDS (PaO2 / FiO2 continued to decrease with a minimum of 85), and the patient was treated with ECMO. Figure b is the lung window, showing diffuse distribution of consolidation and bronchial meteorology in both lungs, mainly dorsal, while the crazy paving can also be seen on the ventral side. Figure d depicts the soft tissue window, and pleural effusion can be found under the dorsal pleura (red arrows). The predominant CT pattern was of consolidation type, with 25 as total CT score. (c) Scan obtained on day 40, lung lesions were further absorbed and reticular involvement was increased, accompanied by fibrotic changes. The predominantly CT sign was the reticular pattern, with 17 as total CT score.