Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest were provided . There is a subtle opacity at the right lung base , which could represent atelectasis or a very early pneumonia . Otherwise , the lungs are clear . The heart and mediastinal contours are stable . Bony structures are intact .
    OUTPUT:
    
Very subtle opacity in the right lung base , which overlaps with the underlying rib and could represent atelectasis , pneumonia is also possible in the right clinical setting .