Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is asymmetric scarring of the left apex compared to the right with a calcification , which may be an indication of prior tuberculosis exposure or infection in the appropriate setting . There is no pleural effusion or pneumothorax . Bony structures are unremarkable .
    OUTPUT:
    
Findings which may indicate prior tuberculosis infection or exposure , but no evidence of acute disease .