Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal and hilar contours are within normal limits . The lungs are clear and a subtle opacity seen at the base of the right lung on prior radiographs is improved . No pleural effusion or pneumothorax is identified .
    OUTPUT:
    
Clear lungs . Previously seen opacity at the base of the right lung is no longer present . No pleural effusion or pneumothorax .