. Author manuscript; available in PMC: 2017 Jun 1.
Published in final edited form as: Ultrasound Med Biol. 2016 Mar 3;42(6):1251–1262. doi: 10.1016/j.ultrasmedbio.2016.01.004
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).