. Author manuscript; available in PMC: 2012 Mar 26.
Published in final edited form as: Ultrasound Med Biol. 2008 Dec 4;35(3):409–415. doi: 10.1016/j.ultrasmedbio.2008.09.004
© 2008 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.