Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest show severe COPD with paucity of lung markings in the upper lung zones . The lungs are hyperinflated with flattening of the diaphragms . These findings are unchanged from the prior exam . Linear opacities at the left base appears stable from prior exam and are likely due to atelectasis or scarring . In the proper clinical setting , an early pneumonia can not be completely excluded . There is no pleural effusion , pulmonary edema , or pneumothorax . The cardiomediastinal silhouette is normal .
    OUTPUT:
    
1 . Stable severe COPD . 2 . Probable left basilar atelectasis and / or scarring . In the proper clinical setting , an early pneumonia can not be fully excluded .