Table 2. Characteristics of CT-Quantitative EAtC Mapping of Lung Parenchyma According to GOLD Stages.

EAtC Mapping	GOLD Stage				P *
	I (n = 85)	II (n = 333)	III (n = 144)	IV (n = 22)
Normal	62.4 ± 19.8	53.5 ± 17.6	37.7 ± 14.5	24.8 ± 7.3	< 0.001
fAT	32.9 ± 20.0	42.0 ± 18.1	58.8 ± 15.0	72.8 ± 7.8	< 0.001
Emph	10.5 ± 11.6	14.2 ± 11.3	23.7 ± 15.0	38.6 ± 12.2	< 0.001

Data are presented as means ± standard deviations of the relative volume (%) of each class. ^*EAtC classes were compared according to GOLD stages using one-way analysis of variance. Post-hoc analysis with Tukey's test showed the significant inter-group differences between all GOLD stages (p < 0.05) except among Emph in GOLD stages I and II. EAtC = emphysema air-trapping composite, Emph = emphysema by EAtC, fAT = functional air trapping by EAtC, GOLD = Global Initiative for Obstructive Lung Disease, Normal = normal lung parenchyma by EAtC