Table 5

Correlation between CT indices and spirometry in the COPD group

FVC (% predicted)FEV1 (% predicted)FEV1/FVCFEF25–75%
Ai/BSA (apical)
WA% (apical) (%)−0.32†−0.32†
Ai/BSA (basal)0.26†
WA% (basal) (%)
Mean Ri (mm)0.28†0.39‡0.29†0.36‡
SD_Ri (mm)−0.35‡
SD_Ri /√BSA−0.34‡
  • −, not significant, †p<0.05, ‡p<0.01.

  • Ai, luminal area; BSA, body surface area; FEF25–75%, mean forced expiratory flow between 25% and 75% of FVC; Ri, radius of inscribed sphere in the airway lumen (see text); SD_Ri and CV_Ri, parameters for shape irregularity of the airway lumen (see text); WA%, percentage ratio of wall area to total airway area.