Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is mildly enlarged . The aorta demonstrates calcifications within the aortic knob . The hilar contours are unremarkable . There may be mild pulmonary vascular congestion , but no overt pulmonary edema is seen . Minimal streaky linear opacities at the lung bases likely reflect atelectasis . No pleural effusion or pneumothorax is identified . No acute osseous abnormalities are seen .
    OUTPUT:
    
Mild bibasilar atelectasis .