Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The inspiratory lung volumes are slightly decreased . The lungs are clear without focal consolidation , pleural effusion or pneumothorax . The cardiomediastinal and hilar contours are within normal limits . There is no evidence of pneumomediastinum . No acute osseous abnormality is detected .
    OUTPUT:
    
No evidence of pneumomediastinum .