Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Moderate enlargement of cardiac silhouette is unchanged . The mediastinal and hilar contours are stable , with calcification of the aortic knob again present . Lungs are clear and the pulmonary vascularity is normal . No pleural effusion or pneumothorax is visualized . Cholecystectomy clips are seen in the right upper quadrant of the abdomen .
    OUTPUT:
    
No acute cardiopulmonary abnormality .