Figure 3:
![Representative examples of airways in lifetime never-smoker men and women. (A) Noncontrast-enhanced three-dimensional reconstructed chest CT image in a lifetime never-smoker 64-year-old man (height, 1.74 m; total lung capacity, 8.1 L; forced expiratory volume in 1 second [FEV1]-to–forced vital capacity [FVC] ratio, 0.80; and FEV1, 127% predicted) shows airway volume of 57 dL, total airway count of 526, and airway fractal dimension of 1.695. (B) Noncontrast-enhanced three-dimensional reconstructed chest CT image in a lifetime never-smoker 63-year-old woman (height, 1.73 m; total lung capacity, 6.1 L; FEV1-to-FVC ratio, 0.76; and FEV1, 100% predicted) shows airway volume of 34 dL, 299 viewable airway branches, and airway fractal dimension of 1.513.](https://www.ncbi.nlm.nih.gov/core/lw/2.0/html/tileshop_pmc/tileshop_pmc_inline.html?title=Click%20on%20image%20to%20zoom&p=PMC3&id=9713451_radiol.212985.fig3.jpg)
Representative examples of airways in lifetime never-smoker men and women. (A) Noncontrast-enhanced three-dimensional reconstructed chest CT image in a lifetime never-smoker 64-year-old man (height, 1.74 m; total lung capacity, 8.1 L; forced expiratory volume in 1 second [FEV1]-to–forced vital capacity [FVC] ratio, 0.80; and FEV1, 127% predicted) shows airway volume of 57 dL, total airway count of 526, and airway fractal dimension of 1.695. (B) Noncontrast-enhanced three-dimensional reconstructed chest CT image in a lifetime never-smoker 63-year-old woman (height, 1.73 m; total lung capacity, 6.1 L; FEV1-to-FVC ratio, 0.76; and FEV1, 100% predicted) shows airway volume of 34 dL, 299 viewable airway branches, and airway fractal dimension of 1.513.