Received: 2 November 2017
Accepted: 22 November 2018
First Online: 6 December 2018
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.The present study was reviewed by the institutional review board and approved before starting the research (Approval number 2, 27th Dec., 2013, Institutional Review Board of Kameda Daiichi Hospital, Niigata, Japan).All the images used in this article were completed following obtaining a written informed consent from each participant.
: Not applicable.
: The authors declares that they have no competing interests.
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