Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are slightly low . Heart size is normal . The aorta is tortuous . The mediastinal and hilar contours are otherwise unremarkable . There is minimal atelectasis in the lung bases . No focal consolidation , pleural effusion or pneumothorax is present . There are multilevel degenerative changes in the thoracic spine . No acute osseous abnormalities seen .
    OUTPUT:
    
Mild bibasilar atelectasis . No evidence of pulmonary edema .