Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Mediastinal and hilar contours are unchanged . Pulmonary vasculature is not engorged . Minimal patchy opacities are noted in the lung bases , findings which could reflect atelectasis but infection is not excluded . No focal consolidation , pleural effusion or pneumothorax is present . There are mild to moderate multilevel degenerative changes seen in the thoracic spine .
    OUTPUT:
    
Mild patchy bibasilar opacities , potentially atelectasis , but infection is not excluded .