Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a radiopaque device projecting over the left shoulder . There is a linear opacity in the right lower lung , which likely represents atelectasis . There is a more confluent opacity at the left lung base . There is a small left pleural effusion . Heart size is normal . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . No pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Confluent opacity at left lung base , which likely represents atelectasis , but coexisting pneumonia can not be ruled out .