Text and Data Mining valid from 2018-04-04
Received: 2 October 2017
Revised: 19 January 2018
Accepted: 29 January 2018
First Online: 4 April 2018
Compliance with ethical standards
: The scientific guarantor of this publication is Tae Jin Yun.
: The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
: No complex statistical methods were necessary for this paper.
: Written informed consent was waived by the Institutional Review Board.
: Institutional Review Board approval was obtained.
: • retrospective• diagnostic or prognostic study• performed at one institution