Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy and CABG . Mild enlargement of the cardiac silhouette is unchanged . The aortic knob is calcified . Mediastinal and hilar contours are similar . Pulmonary vasculature is normal . Lungs are clear . No pleural effusion or pneumothorax is present . Moderate degenerative changes are seen within the thoracic spine peer
    OUTPUT:
    
No acute cardiopulmonary abnormality .