. Author manuscript; available in PMC: 2013 Jan 1.
Published in final edited form as: Ultrasound Med Biol. 2011 Nov 21;38(1):50–61. doi: 10.1016/j.ultrasmedbio.2011.10.002
© 2011 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.