Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patchy retrocardiac opacity could represent early pneumonia . There is no effusion or pneumothorax . The cardiomediastinal silhouette is normal . Imaged osseous structures are intact . No free air below the right hemidiaphragm is seen .
    OUTPUT:
    
Patchy retrocardiac opacity could represent early pneumonia .