Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is normal in size . The mediastinal contours appear within normal limits . There is no mediastinal widening radiographically . There is no pleural effusion or pneumothorax . The lungs appear clear aside from patchy left perihilar and infrahilar opacity which is suspected to reflect slight atelectasis . Otherwise , the lungs appear clear . Small anterior osteophytes are present along the anterior lower thoracic spine .
    OUTPUT:
    
Patchy left mid to lower lung opacity , probably due to minor atelectasis .