. Author manuscript; available in PMC: 2014 May 5.
Published in final edited form as: Ultrasound Med Biol. 2011 May 5;37(6):980–995. doi: 10.1016/j.ultrasmedbio.2011.03.004
© 2011 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.