Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since chest radiographs dated ___ , the left lung base is less well aerated . A confluent area of opacification in the left lower lobe extends superiorly to the level of the hilum . Shadowing of the left hemidiaphragm is likely due to the atelectasis and a small pleural effusion . The heart is normal in size and the pleural surfaces are otherwise normal .
    OUTPUT:
    
Increased left lower lobe atelectasis associated with a small , but increased , left pleural effusion .