Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . Rounded opacity projecting adjacent to the superior aspect of the right heart border is unchanged , possibly a pulmonary vein . The aorta is mildly tortuous . Mediastinal and hilar contours otherwise are unchanged . The pulmonary vascularity is normal . No focal consolidation , pleural effusion or pneumothorax is seen . Minimal streaky opacity in the retrocardiac region may reflect atelectasis , but early infection is not completely excluded . There is no pneumothorax . The lungs are mildly hyperinflated .
    OUTPUT:
    
Streaky retrocardiac opacity could reflect atelectasis though infection can not be completely excluded .