Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are low . The heart is not enlarged . Faint opacity at the left base likely reflects atelectasis . The right lung is relatively clear . The mediastinal and hilar contours are normal . There is no large pleural effusion or pneumothorax .
    OUTPUT:
    
Faint opacity at the left base may reflect atelectasis . There is no convincing evidence of pneumonia . If confirmation is desired then formal PA and lateral radiographs are recommended .