Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear . The hilar and cardiomediastinal contours are normal . There are atherosclerotic calcifications in the aortic arch . There is no pneumothorax or pleural effusion . There is mild prominence of interstitial markings , which is a chronic finding . There is no pulmonary edema . Linear opacities at the bilateral bases are unchanged from prior examinations and may represent atelectasis or scarring .
    OUTPUT:
    
1 . Prominence of interstitial markings , which is a chronic finding . 2 . Linear opacities in the bibasilar region has been seen on multiple prior studies and may represent scarring or atelectasis . In the right clinical setting , infection should be considered .