Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to ___ , the retrocardiac opacification , probably in the right lower lobe , has resolved . There is no pleural effusion or pneumothorax . No pulmonary edema . Heart size is normal . Mediastinal and hilar contours are normal .
    OUTPUT:
    
Resolved retrocardiac , probably right lower lobe , opacification .