Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear . The aorta is slightly tortuous . The heart size is top normal . No pleural effusion , pneumothorax , or pneumonia . There is no evidence of pneumomediastinum on this radiograph . The patient 's known swallowed chicken bone is seen at the very edge of the film ; no other foreign bodies are present . The trachea is midline .
    OUTPUT:
    
No evidence of pneumomediastinum on this radiograph ; a tiny amount of mediastinal air near the carina on the CT of the neck from the same day is beyond the resolution of chest x-ray .