Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hyperinflated with flattened diaphragms , consistent with known COPD . There is a sublte predominantly linear opacity in the right lung base . There is no pleural effusion or pneumothorax . The cardiomediastinal silhouette is unremarkable .
    OUTPUT:
    
1 . Subtle opacity in the right lung base , which may represent atelectasis but an early focus of pneumonia is also possible . If the diagnosis is in doubt clinically , short - term followup radiograph could be obtained . 2 . Pulmonary hyperinflation , consistent with known COPD .