. Author manuscript; available in PMC: 2018 Apr 17.
Published in final edited form as: Tomography. 2018 Mar;4(1):14–25. doi: 10.18383/j.tom.2017.00020
Published by Grapho Publications, LLC This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).