Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are again noted . There are persistent interstitial markings at the bases , greater on the right which are similar but less extensive than on prior . Elsewhere , the lungs are clear . The cardiomediastinal silhouette is within normal limits . Atherosclerotic calcifications are seen at the aortic arch .
    OUTPUT:
    
Bibasilar opacities , right greater than left . Given appearance these could be chronic in nature although superimposed atelectasis , infection or aspiration would be possible .