Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are normal . Pulmonary vascularity is normal . Minimal streaky left lower lobe opacity may reflect atelectasis , but infection can not be excluded . No focal consolidation , pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Minimal streaky opacity in the left lower lobe , most likely reflective of atelectasis , but an area of infection can not be completely excluded .