Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . This causes crowding of the bronchovascular structures . The heart size is mildly enlarged . The mediastinal and hilar contours are unremarkable . There is no pulmonary edema . Evaluation of the lung bases is somewhat limited due to the presence of low lung volumes , with patchy opacities at the bases likely reflective of atelectasis . No focal consolidation , pleural effusion or pneumothorax is detected . Mild degenerative changes of the thoracic spine are noted .
    OUTPUT:
    
Low lung volumes with mild bibasilar atelectasis .