Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest demonstrate well - expanded and clear lungs . Heart is normal in size , and mediastinal contour is unremarkable . There is no pleural effusion or pneumothorax . Known pneumomediastinum is much better appreciated on the chest CT from earlier today . The upper abdomen is unremarkable .
    OUTPUT:
    
Pneumomediastinum is better appreciated on the CT and is very subtle on the radiograph .