Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and mitral valve replacement . Heart size is difficult to assess given the presence of moderate bilateral pleural effusions which are relatively unchanged compared to the prior exam . The mediastinal contour appears unchanged , and no overt pulmonary edema is demonstrated . There are bibasilar compressive atelectatic changes noted . No pneumothorax is seen . No acute osseous abnormalities present .
    OUTPUT:
    
Relatively unchanged moderate bilateral pleural effusions with bibasilar atelectasis .