Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The previous opacity in the right lower lobe has mostly resolved , with minimal residual opacity remaining . Otherwise , the lungs are clear . Cardiac silhouette , hilar contours , and pleural surfaces are unremarkable . No pleural effusion or pneumothorax . No free air .
    OUTPUT:
    
Minimal right lower lobe opacity , possibly atelectasis but infection can not be excluded .