. Author manuscript; available in PMC: 2013 Apr 1.
Published in final edited form as: Ultrasound Med Biol. 2012 Feb 15;38(4):651–660. doi: 10.1016/j.ultrasmedbio.2011.12.005
© 2011 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.