Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are noted with secondary crowding of the bronchovascular markings . Prominence of the upper mediastinum is likely secondary to low lung volumes and portable supine technique . The cardiac silhouette is within normal limits . No acute osseous abnormalities .
    OUTPUT:
    
Low lung volumes no definite superimposed acute cardiopulmonary process .