Table 2.
Summary of the quantitative metrics of enrolled CT image
| Variables | No ARDS (N=51) | ARDS existence (N=301) | Total (N=352) | |||
|---|---|---|---|---|---|---|
| Mean | Sd | Mean | Sd | Mean | Sd | |
| ***Total Volume (%) | 4.17 | 6.08 | 19.39 | 10.36 | 6.38 | 8.69 |
| ***Mean Density (HU) | 607.59 | 121.71 | -479.02 | 152.95 | -588.96 | 134.34 |
| ***Zone1 Proportion (%) | 0.56 | 1.00 | 1.40 | 1.33 | 0.68 | 1.10 |
| ***Zone2 Proportion (%) | 0.30 | 0.47 | 0.84 | 0.70 | 0.38 | 0.54 |
| ***Zone3 Proportion (%) | 0.21 | 0.33 | 0.70 | 0.51 | 0.28 | 0.40 |
| ***Zone4 Proportion (%) | 0.14 | 0.24 | 0.54 | 0.37 | 0.20 | 0.30 |
| ***Zone5 Proportion (%) | 0.10 | 0.18 | 0.44 | 0.30 | 0.15 | 0.23 |
| ***Zone6 Proportion (%) | 0.07 | 0.14 | 0.37 | 0.27 | 0.12 | 0.19 |
| ***Zone7 Proportion (%) | 0.06 | 0.11 | 0.34 | 0.28 | 0.10 | 0.18 |
| ***Zone8 Proportion (%) | 0.05 | 0.10 | 0.34 | 0.29 | 0.09 | 0.18 |
| ***Zone9 Proportion (%) | 0.06 | 0.15 | 0.50 | 0.48 | 0.13 | 0.27 |
| ***Zone10 Proportion (%) | 0.03 | 0.07 | 0.26 | 0.28 | 0.06 | 0.15 |
| ***Vi Proportion (%) | 2.18 | 2.97 | 8.41 | 5.09 | 3.08 | 4.01 |
| ***Vp Proportion (%) | 2.00 | 3.37 | 10.97 | 7.95 | 3.30 | 5.36 |
Zonex indicated the volume proportion of the regions with specific density within the infection, including (zone 1: <-750 HU), (zone 2: from -750 HU to -650 HU), (zone 3: -649 HU to -550 HU), (zone 4: -549 HU to -450 HU), (zone 5: -449 HU to -350 HU), (zone 6: -349 HU to -250 HU), (zone 7: -249 HU to -150 HU), (zone 8: -149 HU to -50 HU), (zone 9: -49 HU to 100 HU) and (zone10:>100 HU). Vi represents the volume proportion of the infection located in the inner part of the lung, including anterior segment of bilateral upper lobes / apical segment of right upper lobe / lingular segment of left upper lobe / middle lobe of right lung/ anterior and medial basal segment of bilateral lower lobes. Vp represents the volume proportion of the infection located in the peripheral part of the lung, including posterior segment of right upper lobe / apicoposterior segment of left upper lobe / superior segment of bilateral lower lobes / lateral and posterior basal segment of bilateral lower lobes. *, **, ***, **** means the P value of t-test between two group >0.05, <0.05, <0.01, <0.001, <0.0001 respectively.