Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . Redemonstrated is a posterior right lower lobe opacity , unchanged . Pulmonary vascularity is mildly prominent , but no overt pulmonary edema is seen . No large pleural effusion or pneumothorax is seen .
    OUTPUT:
    
Right lower lobe opacity may represent pneumonia , though in the absence of infectious symptoms , further evaluation is warranted with CT .