. Author manuscript; available in PMC: 2013 Jun 1.
Published in final edited form as: Ultrasound Med Biol. 2012 Apr 12;38(6):982–988. doi: 10.1016/j.ultrasmedbio.2012.02.021
© 2012 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.