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 unchanged . The lung volumes are low . Patchy medial basilar opacity suggests minor atelectasis . Otherwise , the lungs appear clear . There is no pleural effusion or pneumothorax . There is no evidence for mediastinal widening or pneumomediastinum .
    OUTPUT:
    
No evidence of acute disease .