Chronic hypersensitivity pneumonitis


The changes are characteristic of pulmonary fibrosis.

This patient had a long history of exposure to pigeons as a hobby, and the CT findings are in keeping with end-stage chronic hypersensitivity pneumonitis.

On HRCT,  chronic hypersensitivity pneumonitis usually has the following features:

  • established pulmonary fibrosis with honeycomb formation
  • may see ground glass opacification
  • areas of lobular air-trapping