Table 1.
Characteristics and findings of the studies included in the systematic review
| Ref. | Type of study | Patients included | Mean age in yr, range | CT scan follow-up | CT evaluation, scoring system |
| Han et al[9], 2020 | Retrospective | 17 surviving and discharged patients with COVID-19 pneumonia | 40 ± 6 | 4 wk (4 weekly CT scan during hospitalization) | Semi-quantitative |
| Wang et al[10], 2020 | Retrospective | 63 patients with asymptomatic/mild, 378 with moderate, 43 with severe/critically COVID-19 pneumonia | 47 (33-57) | From symptoms onset to beyond day 15 | Quantitative |
| Liang et al[11], 2020 | Retrospective | 88 patients with mild COVID-19 pneumonia | 42.7 (4-82) | 3 wk after disease onset | Semi-quantitative |
| Sun et al[23], 2021 | Case series | 11 patients with severe COVID-19 pneumonia | 52 (33-75) | CT scan during hospitalization (not well defined, at least 3 wk during hospitalization) | Qualitative |
| Zhou et al[12], 2020 | Retrospective | 100 patients with COVID-19 pneumonia (without ARDS) | 52.3 ± 13.1 (27-80) | CT during hospitalization (from symptoms onset to beyond day 21) | Semi-quantitative |
| Wang et al[13], 2020 | Retrospective | 126 patients with COVID-19 pneumonia, (severe and critical cases excluded) | 41.2 ± 10.8 | CT scan during hospitalization (mean days of hospitalization 22 ± 5 d (12-40) | Qualitative |
| Wang et al[14], 2020 | Retrospective | 79 patients with non-severe (mild/common) COVID-19 pneumonia, 27 with severe pneumonia | 48.0 ± 15.4 | CT scan during hospitalization (mean days of hospitalization 25) + CT scan at 2-4 wk after discharge | Semi-quantitative |
| Zhang et al[15], 2020 | Retrospective | 33 patients with moderate COVID-19 pneumonia | 49.0 ± 15.5 | CT scan during hospitalization (mean days of hospitalization 20.8, range 18-37) | Semi-quantitative |
| Feng et al[16], 2020 | Retrospective | 19 patients with COVID-19 pneumonia | 43.6 ± 15.5 (10-67) | 0-34 d after symptoms onset | Quantitative |
| Liu et al[17], 2020 | Retrospective | 149 discharged patients with COVID-19 pneumonia (142 pneumonia, 7 severe pneumonia, no critical patients included) | 43 (36-56) | Basal CT scan at discharge and at 1st, 2nd and 3rd week after discharge | Semi-quantitative |
| Pan et al[18], 2020 | Retrospective | 105 patients with COVID-19 pneumonia (severe pneumonia excluded) | 48.6 ± 13.1 (23-72) | 1-47 d after symptoms onset | Semi-quantitative |
| Zhuang et al[19], 2021 | Retrospective | 22 patients with COVID-19 pneumonia with solitary pulmonary lesion | 40.7 ± 10.3 (23-54) | CT scan during hospitalization (mean days of hospitalization 19 d, range: 11-44) + first CT scan after discharge | Semi-quantitative |
| Urciuoli and Guerriero[24], 2020 | Case series | 6 patients with mild COVID-19 pneumonia | 59.5 | First CT on admission and 4 mo after symptoms onset | Qualitative |
| Zhang et al[20], 2020 | Retrospective | 53 patients with common COVID-19 pneumonia, 20 patients with severe COVID-19 pneumonia | 45 ± 14 common pneumonia, 50 ± 15 severe pneumonia | 0-30 d after symptoms onset | Quantitative |
| Pan et al[21], 2020 | Retrospective | 21 patients with COVID-19 pneumonia (severe pneumonia excluded) | 40 ± 9 (25-63) | 0-26 d after symptoms onset | Semi-quantitative |
| Wang et al[22], 2020 | Prospective | 90 patients with COVID-19 pneumonia | 45 ± 14 (5-43) | 0-24 d after symptoms onset | Semi-quantitative |
ARDS: Acute respiratory distress syndrome; COVID-19: Coronavirus disease 2019; CT: Computed tomography.