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 a patchy opacity projecting over the left lower lobe suggesting minor atelectasis or scarring . The lungs appear otherwise clear . No discrete lung nodules identified . There are no pleural effusions or pneumothorax . Mild degenerative changes are present along the mid thoracic spine .
    OUTPUT:
    
1 . No evidence of acute disease . 2 . No discrete lung nodule identified although there is patchy atelectasis or scarring in the left lower lobe . Correlation to prior outside imaging is recommended regarding the history of a lung nodule . Many lung nodules are not visible radiographically , including ones of substantial size .