Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the prior study , there has been no significant change in perihilar opacities , likely representing mild pulmonary edema . The lung volumes are low , and there is no appreciable pleural effusion bilaterally . A small amount of atelectasis is present at the lung bases . The cardiomediastinal contours are unremarkable . Support and monitoring devices are unchanged in position . No pneumothorax is present .
    OUTPUT:
    
Mild pulmonary edema is unchanged .