Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours are stable . The heart is at the upper limits of normal size . There is no pleural effusion or pneumothorax . The lungs appear clear . Old rib fractures appear unchanged . Mild rightward convex curvature is again centered along the lower thoracic spine .
    OUTPUT:
    
No evidence of acute disease .