Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The aortic knob is calcified . The mediastinal and hilar contours are unremarkable . Numerous mediastinal clips are present . Pulmonary vascularity is normal and the lungs are clear . No pleural effusion or pneumothorax is seen . There are multilevel degenerative changes in the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary process .