Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral views of the chest provided . There is subtle linear opacity abutting the left heart border which could represent atelectasis versus in early inferior lingular pneumonia . Otherwise the lungs are clear . The heart is mildly enlarged . Mediastinal contour is normal . Bony structures are intact .
    OUTPUT:
    
Atelectasis versus early pneumonia in the lingula .