Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear . The cardiac , hilar and mediastinal contours are normal . No pleural abnormality is seen . Intact median sternal wires . Considerable calcification of the descending thoracic aorta .
    OUTPUT:
    
Considerable calcification of the descending thoracic aorta , but no evidence of edema or pneumonia .