Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded . Somewhat linear opacities at the bilateral lung bases are unchanged , possibly reflecting atelectasis or scarring . Lungs are otherwise clear . No pleural effusion or pneumothorax . Heart size is normal . Cardiomediastinal and hilar silhouettes are unremarkable . Mild tortuosity of the descending thoracic aorta with aortic knob calcifications is unchanged .
    OUTPUT:
    
No acute cardiopulmonary abnormality .