Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are low lung volumes with persistent elevation of the right hemidiaphragm . Bibasilar opacities are somewhat worse compared to the prior exam . Normal heart size , mediastinal and hilar contours . No pleural effusion or pneumothorax .
    OUTPUT:
    
Low lung volumes with bibasilar opacities likely reflecting atelectasis ; although , superimposed pneumonia is possible .