Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are normal . The pulmonary vasculature is normal . Focal opacities within the medial aspect of both lung bases may reflect areas of atelectasis or infection . No large pleural effusion or pneumothorax is identified . No acute osseous abnormality is seen .
    OUTPUT:
    
Bibasilar opacities may reflect areas of atelectasis or infection . No pulmonary edema .