Table 4.
Comparison between inspiratory and expiratory correlation coefficients.
| Quantified CT parameter | Lung function parameter | Correlation inspiration | Correlation expiration | z value | p value |
|---|---|---|---|---|---|
| Volume | VC | 0.0577 | −0.2367 | 3.1409 | 0.0017 |
| Volume | FEV1 | −0.1314 | −0.4643 | 3.631 | 0.0003 |
| Volume | FEV1%VC | −0.3605 | −0.5225 | 1.8699 | 0.0615 |
| Volume | RV | 0.3587 | 0.6466 | −3.3049 | 0.001 |
| Volume | TLC | 0.3809 | 0.5503 | −1.9779 | 0.0479 |
| Volume | RV%TLC | 0.1813 | 0.549 | −4.0252 | 0.0001 |
| Volume | sRtot | 0.102 | 0.4345 | −3.6152 | 0.0003 |
| MLD | VC | −0.0194 | 0.1563 | −1.9585 | 0.0502 |
| MLD | FEV1 | 0.2186 | 0.4696 | −2.9337 | 0.0033 |
| MLD | FEV1%VC | 0.4856 | 0.6376 | −2.005 | 0.045 |
| MLD | RV | −0.4421 | −0.6362 | 2.4796 | 0.0132 |
| MLD | TLC | −0.5098 | −0.6378 | 1.7201 | 0.0854 |
| MLD | RV%TLC | −0.2924 | −0.6108 | 3.7492 | 0.0002 |
| MLD | sRtot | −0.3061 | −0.5225 | 2.5933 | 0.0095 |
| FWHM | VC | 0.0602 | 0.2715 | −1.8312 | 0.0671 |
| FWHM | FEV1 | 0.0918 | 0.4228 | −2.9634 | 0.003 |
| FWHM | FEV1%VC | 0.1818 | 0.403 | −1.9774 | 0.048 |
| FWHM | RV | −0.1707 | −0.416 | 2.1972 | 0.028 |
| FWHM | TLC | −0.1718 | −0.3402 | 1.4834 | 0.138 |
| FWHM | RV%TLC | −0.0505 | −0.4579 | 3.6813 | 0.0002 |
| FWHM | sRtot | −0.0756 | −0.3345 | 2.2735 | 0.023 |
| LAV | VC | −0.2261 | −0.346 | 3.1849 | 0.0014 |
| LAV | FEV1 | −0.3907 | −0.4465 | 1.5801 | 0.1141 |
| LAV | FEV1%VC | −0.4002 | −0.336 | −1.7761 | 0.0757 |
| LAV | RV | 0.5293 | 0.5748 | −1.3982 | 0.1621 |
| LAV | TLC | 0.4354 | 0.405 | 0.8695 | 0.3846 |
| LAV | RV%TLC | 0.4527 | 0.5015 | −1.4274 | 0.1535 |
| LAV | sRtot | 0.5235 | 0.5602 | −1.1266 | 0.2599 |
MLD: mean lung density; FWHM: full width half max; LAV: low attenuation volume; VC: vital capacity; FEV1: forced expiratory volume in one second; FEV1%VC: Tiffeneau index; RV: residual volume; TLC: total lung capacity; sRtot: specific total airway resistance.