Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear unchanged . Opacity effacing the right cardiophrenic angle is probably due to minor atelectasis . In the left lower lobe there is persistent opacity but decreased and similar in distribution . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Persistent but decreased left lower lobe opacity . Although recurrent or slowing resolving pneumonia is not excluded , appearance may be due to waxing and waning chronic atelectatic change without available long - term prior follow - up to assess for the possibility .