Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is normal . Mediastinal and hilar contours are unremarkable . Atherosclerotic calcifications are noted at the aortic knob . Pulmonary vasculature is normal . The lungs are clear . No pleural effusion or pneumothorax is present . There are mild multilevel degenerative changes seen in the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary abnormality .