Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a left lower lobe opacity , which most likely represents atelectasis , but infection should be considered in the appropriate clinical setting . No other consolidation . No effusion or pneumothorax . Cardiomediastinal and hilar contours are normal . No subdiaphragmatic air . No acute osseous abnormalities identified .
    OUTPUT:
    
Left lung base opacity may represent atelectasis or infection .