Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . The mediastinal and hilar contours are relatively unchanged with mild unfolding of thoracic aorta . The pulmonary vascularity is not engorged . Bibasilar airspace opacities have a somewhat linear configuration are likely related to atelectasis . Infection , however , can not be excluded particularly at the right lung base . No pleural effusion or pneumothorax is identified . There are no acute osseous abnormalities .
    OUTPUT:
    
Bibasilar airspace opacities , likely reflective of atelectasis though infection particularly at the right lung base is not completely excluded .