Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is normal . Minimal atherosclerotic calcifications are present at the aortic knob . Mediastinal and hilar contours are normal . Pulmonary vasculature is normal . Lungs are clear . No pleural effusion or pneumothorax . Mild degenerative changes are seen in the lower thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary abnormality .