Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are reduced . The heart size is mild to moderately enlarged but unchanged . The aorta remains tortuous . Hilar contours are normal . There is no pulmonary vascular congestion . Streaky opacities in the lung bases likely reflect atelectasis . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Streaky bibasilar airspace opacities most likely reflect atelectasis , but infection is not completely excluded .