Correlation between CT indices and spirometry in the BA group
| FVC (% predicted) | FEV1 (% predicted) | FEV1/FVC | FEF25–75% | |
|---|---|---|---|---|
| Ai/BSA (apical) | − | − | − | − |
| WA% (apical) (%) | − | − | − | − |
| Ai/BSA (basal) | 0.51‡ | 0.55‡ | − | 0.49‡ |
| WA% (basal) (%) | −0.50‡ | −0.57‡ | − | −0.46† |
| Mean Ri (mm) | − | − | − | − |
| SD_Ri (mm) | − | − | − | − |
| SD_Ri /√BSA | − | − | − | − |
| CV_Ri | − | − | − | − |
− not significant, †p<0.05, ‡p<0.01.Ai, luminal area; BA, bronchial asthma; 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.