Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are low lung volumes . Bibasilar opacities may represent atelectasis due to low lung volumes however can not rule out pneumonia . No pneumothorax or pleural effusion . Heart size is difficult to evaluate .
    OUTPUT:
    
Low lung volumes . Bibasilar opacities may represent atelectasis due to low lung volumes however can not rule out pneumonia .