Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest are compared to previous exam from ___ . New when compared to prior is an ll defined left basilar opacity , not as clearly seen on the lateral exam . Elsewhere , the lungs are clear . There is no effusion . Cardiac silhouette is enlarged but stable in configuration . The aorta is slightly tortuous . Osseous and soft tissue structures are unremarkable .
    OUTPUT:
    
Subtle left basilar opacity , better seen on the frontal than on the lateral could be due to atelectasis ; however , developing infiltrate is also possible . Clinical correlation suggested .