Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are low , accentuating the pulmonary vasculature , with no evidence of overt pulmonary edema . Streaky opacification in the left lung base could be due to atelectasis alone , however underlying infection can not be excluded . There is no large pleural effusion or pneumothorax . The heart size is normal .
    OUTPUT:
    
Streaky left lung base opacification , possibly atelectasis , however underlying infection can not be excluded in the appropriate clinical setting .