Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are decreased compared to the prior study . Heart size is mild to moderately enlarged but relatively unchanged . The aorta is diffusely calcified . There is crowding of the bronchovascular structures but no overt pulmonary edema is demonstrated . Minimal streaky bibasilar airspace opacities likely reflect atelectasis . No definite pleural effusion or pneumothorax is seen . There is minimal scarring within the lung apices . No acute osseous abnormalities are detected .
    OUTPUT:
    
Low lung volumes with probable mild bibasilar atelectasis .