Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The aorta remains tortuous . The mediastinal and hilar contours are similar . The pulmonary vasculature is not engorged . Patchy opacities in the lung bases likely reflect areas of atelectasis . No focal consolidation , pleural effusion or pneumothorax is present . Multilevel mild to moderate degenerative changes are seen in the thoracic spine .
    OUTPUT:
    
Mild bibasilar atelectasis without focal consolidation .