Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear . The cardiomediastinal silhouette is mildly enlarged . The hilar contours are within normal limits . The pleural surfaces are clear without effusion or pneumothorax . There is evidence of diffuse idiopathic skeletal hyperostosis ( DISH ) of the thoracic spine .
    OUTPUT:
    
Mildly enlarged cardiomediastinal silhouette , largely unchanged from prior examination .