Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is mildly enlarged . The mediastinal and hilar contours appear within normal limits . The aortic arch is partly calcified . There is no pleural effusion or pneumothorax . The lungs appear clear . There is mild elevation of the right hemidiaphragm . Mild degenerative changes are noted along the thoracic spine .
    OUTPUT:
    
No evidence of acute disease .