Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is at the upper limits of normal size . The mediastinal and hilar contours are unremarkable . The lungs appear clear . There are no pleural effusions or pneumothorax . The patient is status post posterior fusion of the cervical spine , as well as lumbar fusion , but incompletely characterized .
    OUTPUT:
    
No evidence of acute disease .