Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are patchy bibasilar opacities . Prominent interstitial markings are likely related to age related changes . No pulmonary edema , pleural effusion or pneumothorax identified . The cardiac and mediastinal contours are normal .
    OUTPUT:
    
Patchy bibasilar opacities most likely represent atelectasis , however , aspiration or infection are not excluded .