Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is normal in size . The mediastinal and hilar contours appear within normal limits . There is no evidence for pneumothorax or pneumomediastinum . Linear opacity in the right middle lobe suggests minor atelectasis or scarring that is unchanged . The lungs are otherwise clear . Mild degenerative changes are similar along the lower thoracic spine .
    OUTPUT:
    
No evidence of acute disease .