Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild enlargement of the cardiac silhouette is unchanged . Mediastinal and hilar contours are within normal limits . The pulmonary vasculature is not engorged . The lungs are clear without focal consolidation , pleural effusion or pneumothorax . Mild degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary abnormality .