Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are present , which accentuates the size of the cardiac silhouette which is at least moderately enlarged . Aortic arch calcifications are present . Mild widening of the superior mediastinum is presumably due to low lung volumes . There is crowding of the bronchovascular structures without overt pulmonary edema demonstrated . Bibasilar airspace opacities likely reflect atelectasis . No large pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Low lung volumes . Mild bibasilar atelectasis .