Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear stable including cardiac enlargement . The lung volumes are low . There is no pleural effusion or pneumothorax . Slight retrocardiac opacity is noted . Within the limitations of technique , the lungs appear otherwise clear .
    OUTPUT:
    
Suggestion of retrocardiac opacity , probably atelectasis in the setting of low volumes . If there is continuing clinical concern for developing pneumonia , however , short - term follow - up radiographs may be helpful , preferably with PA and lateral technique if feasible .