Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal and hilar contours are stable . The heart is top normal in size . There are opacities at the base of the left lung which could represent atelectasis or infection in the appropriate clinical setting . No pleural effusion or pneumothorax is identified .
    OUTPUT:
    
Subtle opacities at the base of the left lung could represent an area of atelectasis or infection in the appropriate clinical setting .