Fig. 2 Evolution of lobar distribution of the (a) number of lobe affected, (b) unilateral and bilateral lobes affected, and (c) lung lobe affected in patients with COVID-19 within 21 days after disease onset. The time after disease onset (day) is categorized as 5 groups, i.e., days 0–3 (patient number = 37), days 4–7 (patient number = 69), days 8–10 (patient number = 53), days 11–14 (patient number = 49), and days 15–21 (patient number = 25)