Funding for this research was provided by:
National Research Foundation of Korea ((# 2017R1C1B5016217)
Article History
Received: 3 January 2019
Revised: 1 February 2019
Accepted: 11 February 2019
First Online: 15 March 2019
Compliance with ethical standards
:
: The scientific guarantor of this publication is Eun Ju Ha.
: 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 obtained from all patients before they underwent US.
: This study was approved by our institutional review board.
: • retrospective• case-control study