Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and CABG . There are persistently low lung volumes . The heart size remains moderately enlarged , and mediastinal contours are stable . There is persistent elevation of the right hemidiaphragm , with bibasilar airspace opacities likely reflective of atelectasis . There is crowding of the bronchovascular structures , but no overt pulmonary edema is present . Small bilateral pleural effusions likely persist . There is no pneumothorax . Clips in the right upper quadrant denote prior cholecystectomy .
    OUTPUT:
    
Bibasilar atelectasis with small bilateral pleural effusions .