Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hyperexpanded and show hyperlucency of the upper lobes consistent with known emphysema . Asymmetric density is noted in the left lower lobe . The cardiomediastinal silhouette , hilar contours and pleural surfaces are normal . No pleural effusion or pneumothorax is present .
    OUTPUT:
    
Moderate COPD . Probable left lower lobe pneumonia .