Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette size is normal . Mediastinal and hilar contours are unchanged . Mild atherosclerotic calcifications are noted at the aortic knob . Pulmonary vasculature is normal . Lungs are clear . No pleural effusion or pneumothorax is seen . No acute osseous abnormality is detected . Degenerative changes are noted involving both AC joints .
    OUTPUT:
    
No acute cardiopulmonary abnormality .