Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided demonstrate retrocardiac opacity which is concerning for left lower lobe pneumonia . Subtle effacement of the right heart border could also represent an early pneumonia in the right middle lobe . Otherwise , the lungs are clear . No effusion or pneumothorax . Mediastinal contour is normal . Heart size appears within normal limits . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
Left lower lobe pneumonia . Possible early consolidation in the right middle lobe .