Model development.

(a) An example cross-sectional slice through one of the CT images. (b) Central airways segmented from the same CT image. The segmentation consists of a centreline and minimum radius information, but is rendered as a series of tubes. The tubes are colour coded by the airway radius (see scale bar below (d)). (c) Lobar segmentations, a distinct colour is used for each lobe. (d) The complete conducting airway tree generated using the segmentations shown and the parent airway radius scheme. The tree is colour coded by airway radius (see scale bar).