Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: As compared to the prior examination , there has been minimal interval change . Redemonstrated is severe emphysema with increased interstitial markings and several large bullae . There is no definitive consolidation , pleural effusion , pneumothorax , or pulmonary edema identified . Stable , mild cardiomegaly is noted . Mediastinal hilar contours are largely unchanged from prior examination .
    OUTPUT:
    
Severe emphysema . Given the patient 's baseline chronic lung disease , is difficult to exclude a superimposed acute process in the appropriate clinical setting .