Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded . There is a hazy opacity in the retrocardiac area , which likely represents atelectasis but could reflect pneumonia or aspiration in the right clinical setting . There are trace bilateral pleural effusions . There is no pneumothorax . The cardiomediastinal silhouette is stable .
    OUTPUT:
    
Retrocardiac opacity , which likely represents atelectasis but which could reflect pneumonia or aspiration in the right clinical setting . Trace bilateral pleural effusions .