Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to the prior radiograph , lung volumes are lower , particularly in the right lower lobe . A new right lower lobe opacity on both views is at least atelectasis . Superimposed pneumonia is not excluded . A small right effusion is new . No pneumothorax . Cardiomediastinal and hilar silhouettes are normal .
    OUTPUT:
    
New right lower lobe opacity is at minimum atelectasis . However given the clinical history , superimposed pneumonia is not excluded .