Ryoo, Hyun Gee
Choi, Hongyoon
Cheon, Gi Jeong
Article History
Received: 29 July 2019
Revised: 19 November 2019
Accepted: 25 November 2019
First Online: 9 December 2019
Compliance with Ethical Standards
:
: Hyun Gee Ryoo, Hongyoon Choi, and Gi Jeong Cheon declare that they have no conflict 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.
: The institutional review board of our institute approved this retrospective study, and the requirement to obtain informed consent was waived.