Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Heart size is within normal limits . The mediastinal and hilar contours are unchanged , with unfolding of the thoracic aorta again noted . The pulmonary vasculature is normal . Patchy and linear opacities in the lung bases likely reflect atelectasis . No focal consolidation , pleural effusion or pneumothorax is demonstrated . There are mild degenerative changes in the thoracic spine .
    OUTPUT:
    
Low lung volumes with mild bibasilar atelectasis .