Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear . Mild - to - moderate enlargement of the cardiac silhouette is not significantly changed . The mediastinal contours are unchanged . There are no pleural effusions . No pneumothorax is seen .
    OUTPUT:
    
1 . No acute cardiac or pulmonary process . 2 . Unchanged mild - to - moderate cardiac enlargement .