Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The mediastinal and hilar contours are normal . On the lateral view , there may be some residual pneumomediastinum noted anterior to the trachea . The pulmonary vasculature is normal . Lungs are clear . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Probable small residual pneumomediastinum noted anterior to the trachea on the lateral view . Otherwise , no acute cardiopulmonary abnormality .