Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral views of the chest demonstrate a moderate - sized left pneumothorax , not significantly changed since the prior outside study . There is no significant mediastinal shift or signs of tension . A small left pleural effusion is noted . Severe background emphysema is again seen . The cardiomediastinal silhouette is unremarkable . No focal consolidation is present .
    OUTPUT:
    
Moderate left pneumothorax and small left pleural effusion , not significantly changed from two hours ago . Severe emphysema .