On the left a smoker with RB-ILD with subtle HRCT-findings. The dominant pattern is ground glass opacification. Additional findings in this patient are paraseptal emphysema in the upper lobes and some subtle septal thickening in the basal parts. Based on these non-specific CT findings there is a broad differential diagnosis and additional clinical information is mandatory for the interpretion of the HRCT. Since this patient is a smoker we first think RB-ILD. In a immunocompromised patient PCP would be on top of the list. If this patient was coughing up blood, this probably would be pulmonary hemorrhage (although we would expect more pulmonary densities in these patients). If this patient was a bird-fancier we would first think hypersensitivity pneumonitis, but mostly these patients do not smoke. #Clinical #Radiology #CTChest #RBILD #RespiratoryBronchiolitis #ILD #RadiologyAssistant
