Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low bilateral lung volumes , however slightly improved since the prior examination . There is persisting bibasilar atelectasis as well as small bilateral pleural effusions . Underlying pneumonia however can not be excluded . No pneumothorax identified . The size of the cardiac silhouette is enlarged but unchanged .
    OUTPUT:
    
Small bilateral pleural effusions as well as bibasilar atelectasis . Underlying pneumonia can not be excluded .