Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Hyperinflation of the lungs , bullous emphysema of the upper lung fields , and flattening of the hemidiaphragms are consistent with severe COPD . No evidence of focal lung consolidation . No pleural effusion or pneumothorax is seen . The cardiac , hilar and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
Severe bullous emphysema not significantly changed compared to prior study . No evidence of pneumonia or cardiac decompensation .