Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are normal . Pulmonary vasculature is normal . Streaky left lower lobe opacity is present along with a small left pleural effusion . Right lung is clear . No pneumothorax is identified . No acute osseous abnormality is detected .
    OUTPUT:
    
Streaky left lower lobe opacity may reflect atelectasis , though infection is not completely excluded in the correct clinical setting . Trace left pleural effusion .