Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Linear opacities in the bilateral upper lobes are overall unchanged and suggest scarring , perhaps related to prior granulomatous disease exposure . Otherwise , lungs are clear . No focal consolidation , effusion , edema , or pneumothorax . The heart size is normal . The mediastinum is not widened . No acute osseous abnormality .
    OUTPUT:
    
1 . No pneumonia . 2 . Persistent bilateral linear opacities are most likely scarring and unchanged , perhaps related to prior exposure to granulomatous disease .