. 2012 Jun 18;13(4):505–509. doi: 10.3348/kjr.2012.13.4.505
Copyright © 2012 The Korean Society of Radiology
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.