Funding for this research was provided by:
Ministry of Education, Culture, Sports, Science and Technology (26460755, 23591760)
Article History
Received: 14 April 2019
Accepted: 7 August 2019
First Online: 19 August 2019
Compliance with ethical standards
: The funding sources had no role in the design or conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication.
: Author TN declares that he has no conflict of interest. Author KI has received honoraria for lecture fees from Nihon Medi-Physics Co., Ltd. (Tokyo, Japan). Author TT declares that he has no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.