Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is normal in size . A mildly convex contour to the left mid mediastinum may be perhaps suggest a promient atrial appendage , . There is no pleural effusion or pneumothorax . The lungs appear clear . Mild degenerative changes are noted along the lower thoracic spine .
    OUTPUT:
    
No evidence of acute disease .