Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low with bibasilar atelectasis . Increased medial right lower lung and retrocardiac opacity most likely represents atelectasis , however aspiration can not be excluded . There may be a small left pleural effusion . No pneumothorax is seen .
    OUTPUT:
    
Bibasilar opacities most likely represent atelectasis , but aspiration can not be excluded .