Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest are compared to prior exam from ___ . A subtle hazy opacity at the left lung base on the frontal not well seen on the lateral view . Elsewhere , the lungs are grossly clear noting stable right apical scarring . The cardiomediastinal silhouette is within normal limits . Osseous and soft tissue structures are unchanged .
    OUTPUT:
    
Subtle opacity at the left lung base on the frontal view , potentially due to atelectasis ; however , developing infiltrate is not excluded .