Document is current

Article History

Received: 3 April 2018

Revised: 17 July 2018

Accepted: 14 August 2018

First Online: 12 September 2018

Compliance with ethical standards

:

: The scientific guarantor of this publication is Qiugen Hu

: 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 study• performed at two institutions