000 Respiratory Bronchiolitis

Respiratory bronchiolitis,

present histologically in all active smokers, is characterised by the accumulation of pigmented “smoker’s macrophages” in respiratory bronchioles and neighbouring alveoli, containing granular, yellow-brown cytoplasmic pigments

Mosaic attenuation pattern. CT scan through lower lobes shows the indirect sign of constrictive obliterative bronchiolitis, in this case the sequel to a severe viral lower respiratory tract infection.
https://pubs.rsna.org/doi/full/10.1148/radiol.13120908
Tree-in-bud pattern. CT scan through lower lobes shows the direct sign of exudative bronchiolitis in a 42-year-old man with a sino-bronchial sepsis syndrome.
https://pubs.rsna.org/doi/full/10.1148/radiol.13120908

 

Links and References

 

TCV

Small Airway Disease Introduction