Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest were provided . There is known scarring in the left lower lobe which likely accounts for the subtle retrocardiac opacity . There is a stable area of scarring in the lingula inferiorly . There is no definite sign of pneumonia or overt CHF . No large pleural effusion or pneumothorax is seen . Heart size is normal . Mediastinal contour is unremarkable . Bony structures appear intact .
    OUTPUT:
    
Stable areas of scarring at the left lung base . No definite signs of pneumonia or CHF .