UIP with honeycombing (left) and chronic HP (right)
Differential diagnosis of Hypersensitivity Pneumonitis.
Subacute stage:
- RB-ILD: seen in smokers, upper lobe predilection, usually associated with centrilobular emphysema.
- Alveolar proteinosis.
Chronic stage:
- UIP: may show very similar HRCT findings. 
- UIP has a strong lower zone distribution.
In chronic HP fibrotic changes are typically seen throughout the whole lung parenchyma from the periphery towards the centrum. #Clinical #Diagnosis #Radiology #CTChest #UIP #Comparison #Chronic #HypersensitivityPneumonitis #Fibrosis #Mimic #ILD #RadiologyAssistant