Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are unchanged from ___ . Both lungs show diffuse emphysematous changes . However , there is no evidence of focal consolidation or pneumothorax . Trace effusion at the left lung base can not be completely excluded . Bony structures are unremarkable .
    OUTPUT:
    
No definite consolidation . Trace left pleural effusion can not be excluded .