Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral views of the chest demonstrate increase in density at the left lung base , which may represent atelectasis or developing infection in the appropriate clinical setting . The cardiac , mediastinal , and hilar contours are normal . No pleural abnormality is seen .
    OUTPUT:
    
Increased density at the left lung base may represent atelectasis or infection in the appropriate clinical setting .