Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette size is top normal . The aorta is mildly unfolded . Hilar contours are normal . The pulmonary vascularity is normal and the lungs are clear . No pleural effusion or pneumothorax is seen . There are mild degenerative changes of the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary abnormality .