Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are linear bibasilar opacities , which likely reflect atelectasis . The lungs are otherwise clear . Heart size is normal . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Linear bibasilar opacities , which likely reflects atelectasis , but underlying viral , or early bacterial pneumonia can not be ruled out .