Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest . There is asymmetric left basilar opacity . Elsewhere , the lungs are clear . The cardiomediastinal silhouette is within normal limits . No acute osseous abnormality is identified .
    OUTPUT:
    
Left basilar opacity , potentially atelectasis , noting that infection is also possible in the appropriate clinical setting .