Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are mildly hyperexpanded , as on prior . Hazy retrocardiac opacity projects over the spine on lateral view . 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 . Surgical clips are seen projecting over the left upper chest .
    OUTPUT:
    
Hazy retrocardiac opacity likely reflecting pneumonia in the appropriate clinical setting . Follow - up chest radiograph to ensure resolution is recommended .