Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of chest demonstrate persistent bibasilar atelectasis . No opacities are concerning for pneumonia . An unfolded thoracic aorta is again present . There may be a small left pleural effusion . No free air is noted . An old right sided clavicular fracture is present .
    OUTPUT:
    
Persistent bibasilar atelectasis .