Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . The hilar and mediastinal contours are normal . Note is made of a clustered nodular opacity in the mid left lung . There is no pleural effusion or pneumothorax . The visualized osseous structures are unremarkable .
    OUTPUT:
    
Subtle increased clustered nodular opcity overlying the mid left lung concerning for pneumonia .