Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . In the right perihilar region , there is a subtle increase in opacification . Otherwise , the hilar and mediastinal contours are normal . There is no pleural effusion or pneumothorax . The visualized osseous structures are unremarkable .
    OUTPUT:
    
Subtle opacity in the right perihilar region , which may be secondary to an infectious process .