Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Again seen is a small left pleural effusion with mild associated scarring or atelectasis of the left lower lobe , unchanged from prior . Severe emphysema , particularly at right base , is unchanged . Region of mild bronchiectasis and post inflammatory or bronchial wall thickening of the right upper lobe is better evaluated on prior CT . The heart size is normal . The mediastinal and hilar contours are unchanged . No pneumothorax is seen .
    OUTPUT:
    
Unchanged small left pleural effusion .