image findings in hypersensitivity pneumonitis include GGO, centrilobular micronodules, and mosaicism
- related: HP hypersensitivity pneumonitis
- tags: #permanent
- source: Fundamentals of High Resolution Lung CT, An Algorithmic Approach to Lung Disease
GGO

- ground glass opacity can be predominant findings in subacute HP
Centrilobular micronodules


- Hypersensitivity pneumonitis with centrilobular distribution

- hypersensitivity pneumonitis with centrilobular consolidation, air bronchogram
- air bronchogram differentiates HP from sarcoidosis (pulmonary sarcoidosis findings include mediastinal lymphadenopathy and perilymphatic nodules)
Mosaicism and headcheese sign



Distribution
- distribution usually more in mid lung and more central in location as compared to lower lung and peripheral in other interstitial pneumonias
Chronic

- fibrosis is finding for chronic HP
- bronchiectasis is more traction than central1