Chung, Hyun Hoon http://orcid.org/0000-0002-5158-7492
Cheon, Gi Jeong
Kim, Jae-Weon
Park, Noh-Hyun
Song, Yong Sang
Article History
Received: 11 May 2017
Accepted: 7 August 2017
First Online: 21 August 2017
Compliance with ethical standards
:
: The authors declare that they have no conflicts of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of retrospective study, formal consent is not required.