Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a right lower lobe opacity and a left retrocardiac opacity which is unchanged from ___ concerning for bibasilar atelectasis . Multiple right healed rib fractures are stable . There is no pneumothorax or pleural effusion . Cardiomediastinal borders and hilar structures are normal . Cardiac size is normal .
    OUTPUT:
    
Persistent right lower lobe and left retrocardiac region likely secondary to bibasilar atelectasis .