Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Tracheostomy tube and left subclavian line are unchanged . Lung volumes are low . There is mild pulmonary vascular redistribution but this is improved compared to the study from 4 days prior . There is patchy areas of volume loss most marked at the bases in the right midlung . An infiltrate could be missed in the retrocardiac region due to low lung volumes
    OUTPUT:
    
Low lung volume .