Relationship of airway dimensions with airflow limitation or lung volumes in chronic obstructive pulmonary disease (COPD)

a) Accurate bronchial skeleton. Source images of b) axial, c) sagittal and d) coronal slices. Yellow lines indicate the same series of airway in parts a, b, c and d. e) A curved multiplanar reconstruction (MPR) image of the selected airway from the right lower lobe. f, g, h and i) Short axis images obtained from the curved MPR image are precisely perpendicular to the long axis of the airway. The numbers of the bronchial generation are f) third, g) fourth, h) fifth and i) sixth.