Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is mildly enlarged but similar . The aorta is tortuous . Mediastinal and hilar contours are unchanged . No overt pulmonary edema is present . Streaky and patchy bibasilar airspace opacities may reflect areas of atelectasis though infection or aspiration can not be excluded . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities identified .
    OUTPUT:
    
Patchy opacities in lung bases may reflect atelectasis , but infection or aspiration can not be excluded in the correct clinical setting .