Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are unchanged with the heart size within normal limits . The aorta is mildly unfolded . Pulmonary vasculature is normal . Lungs are clear . No pleural effusion or pneumothorax is present . There are mild diffuse degenerative changes in the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary abnormality .