Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Chronic scarring and atelectasis at the right lung base is again demonstrated . There is a small right pleural effusion . Difficult to exclude a superimposed pneumonia . Heart size and mediastinal contours are normal . No pneumothorax .
    OUTPUT:
    
1 . Trace right pleural effusion . 2 . Chronic right lower lobe scarring with minimal increase in opacification , which could be atelectasis or early pneumonia .