Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The mediastinal contours are unremarkable , and the hila appear stable . Patchy ill - defined opacity in the left lung base is concerning for infection in the correct clinical setting . Trace left pleural effusion is present . The right lung appears grossly clear . No pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Streaky ill - defined opacity within the left lung base is concerning for pneumonia . Small left pleural effusion . Followup radiographs after treatment are recommended to ensure resolution of this finding .