Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal with trace unfolding of the aorta . Aortic knob calcifications are mild . Cardiomediastinal silhouette and hilar contours are normal . Lungs are clear . Pleural surfaces are clear without effusion pneumothorax .
    OUTPUT:
    
1 . No acute cardiopulmonary abnormality . 2 . Previously characterized bibasilar nodules are better evaluated by CT , not evident on radiography .