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 appear unremarkable . There are no pleural effusions or pneumothorax . The lungs appear clear . Bony structures are unremarkable aside from slight degenerative changes along the upper - to - mid thoracic spine .
    OUTPUT:
    
No evidence of acute disease .