Table 2.

Quantitative analysis of lung ground-glass opacification and the density of ground-glass at baseline.

Quantitative analysis of HRCT	PAP (n = 40)
Total opacification percentage of whole lung (%)	32.49 ± 24.15
Opacification percentage of right upper lobe (%)	35.69 ± 27.76
Opacification percentage of right middle lobe (%)	31.26 ± 24.55
Opacification percentage of right lower lobe (%)	34.29 ± 28.71
Opacification percentage of left upper lobe (%)	31.50 ± 23.51
Opacification percentage of left lower lobe (%)	29.58 ± 26.78
Percentage of HU value of (-∞,-750)H (%)	5.54 ± 5.34
Percentage of HU value of [-750,-300)H (%)	17.83 ± 14.28
Percentage of HU value of [-300, 49)H (%)	7.19 ± 7.20
Percentage of HU value of [50+)H (%)	1.85 ± 2.48

HRCT: high-resolution computed tomography; PAP: pulmonary alveolar proteinosis; HU: Hounsfield unit.