Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low bilateral lung volumes . Since the prior examination however there is mild improvement in the extent of the pulmonary edema . Mild retrocardiac opacities likely reflect atelectasis . No pneumothorax identified . The size the cardiac silhouette is enlarged but unchanged . Again noted is calcification of the aortic arch . Degenerative changes of both glenohumeral joints .
    OUTPUT:
    
Persistence of but decreased pulmonary edema .