Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Borderline enlargement of the cardiac silhouette is unchanged . Mediastinal and hilar contours are normal . Pulmonary vasculature is normal . Lungs are clear . No pleural effusion or pneumothorax is present . Mild degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary abnormality .