Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are low . The cardiac silhouette size is top normal . Mediastinal and hilar contours are unchanged . There is crowding of the bronchovascular structures . Patchy ill - defined opacity at the lung bases may reflect atelectasis , but aspiration or infection is not excluded . There is no pneumothorax or pleural effusion . No acute osseous abnormality is seen . S - shaped scoliosis of the thoracolumbar spine is present . Old left - sided rib fractures are unchanged .
    OUTPUT:
    
Low lung volumes . Patchy opacities at the lung bases may reflect atelectasis , though infection or aspiration is not excluded .