Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The aorta is tortuous . Mediastinal and hilar contours are unremarkable . The pulmonary vasculature is not engorged . Severe emphysema with upper lobe predominance is again noted . Patchy opacities in the lung bases may reflect areas of atelectasis , however infection is not excluded in the correct clinical setting . No pneumothorax is seen . Minimal blunting of the costophrenic angles posteriorly on the lateral view may reflect chronic pleural thickening . No large pneumothorax is identified . Mild degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
Severe emphysema . Patchy opacities within the lung bases may reflect atelectasis , but infection is not excluded in the correct clinical setting .