Semi-quantitative scoring system to quantify COVID-19 lung involvement [41]
| Area involved | Scores |
|---|---|
| No involvement | 0 |
| < 5% involvement | 1 |
| 25% involvement | 2 |
| 26–49% involvement | 3 |
| 50–75% involvement | 4 |
| > 75% involvement | 5 |
The total CT score is the sum of the scores of each of the five lung lobes and ranges from 0 (no involvement) to 25 (maximum involvement), which approximates the degree of lung involvement and has prognostic significance for subsequent disease progression [41]