Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are low . There are still bibasilar atelectases with very mild left retrocardiac opacities that could be atelectasis , but aspiration or superimposed infection can not be excluded . There is no pneumothorax and no significant pleural effusion . The mediastinal and cardiac contours are unchanged .
    OUTPUT:
    
There is no significant change since the previous exam . There are bibasilar mild atelectases . Stable left retrocardiac opacities can be atelectasis , but superimposed infection or aspiration can not be excluded in the appropriate clinical setting .