Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Chronic fibrotic changes in the upper lobes and severe emphysema in the lower lobes are again noted . Heterogeneous opacity in the posterior aspect of left lower lobe is similar to ___ , however it has been increasing since ___ . No new opacity is identified since ___ to suggest pneumonia . There is no pneumothorax or pleural effusion . Cardiomediastinal silhouette is unchanged .
    OUTPUT:
    
No new abnormality is identified since ___ to suggest pneumonia .