CT measurement

Correlation coefficient (r) for spirometric measurement

FEV₁

FEV₁

(%predicted)

FEV₁/FVC

FEF_25-75%

FEF_25-75%

(%predicted)

Peak flow

Mean tracheal CSA

0.388

(P < 0.05)

0.110

(NS)

0.211

(NS)

0.255

(NS)

0.145

(NS)

0.358

(P < 0.05)

Minimum tracheal CSA

0.770

(P < 0.0001)

0.485

(P < 0.01)

0.490

(P < 0.01)

0.635

(P < 0.0001)

0.556

(P < 0.01)

0.748

(P < 0.0001)

LAA%

−0.164

(NS)

−0.172

(NS)

−0.260

(NS)

−0.234

(NS)

−0.260

(NS)

−0.080

(NS)