Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest were provided . Subtle retrocardiac opacity could represent an early right lower lobe pneumonia . No effusion or pneumothorax . Cardiomediastinal silhouette is normal . Bony structures are intact .
    OUTPUT:
    
Subtle opacity in the retrocardiac space concerning for an early right lower lobe pneumonia .