Fig. 2

Axial CT image in a 46-year-old female never smoker (a), diagnosed with chronic hypersensitivity pneumonitis following surgical lung biopsy. An upper lobe predominant fibrosing lung disease associated with honeycomb cysts is demonstrated. On the CALIPER colour overlay image (b), ground glass opacities (yellow) are interspaced with reticular pattern (orange) in the lung periphery. In the anterior left upper lobe, there are honeycomb cysts visible (brown). Light and dark green areas represent normal lung parenchyma. Axial CT image in a 55-year-old female 2-pack-year ex-smoker (c), diagnosed with chronic hypersensitivity pneumonitis following surgical lung biopsy with more extensive fibrosis involving the lower lobes. CALIPER colour overlay images show minor misclassification of traction bronchiectasis as honeycomb cysts in the left lower lobe (d), but extensive ground glass opacities (yellow) and interspaced reticular pattern (orange)