Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Heart size is mildly enlarged but unchanged . The mediastinal and hilar contours are unremarkable . There is crowding of the bronchovascular structures , which may be due to low lung volumes . Additionally assessment of the lung bases is somewhat limited due to low lung volumes , with probable atelectatic changes noted . No pleural effusion or pneumothorax is seen . Mild loss of height of a vertebral body at the thoracolumbar junction at appears chronic .
    OUTPUT:
    
Low lung volumes with probable mild bibasilar atelectasis .