Ban, Kanako http://orcid.org/0000-0002-7244-2436
Tsunoda, Hiroko
Watanabe, Takanori
Kaoku, Setsuko
Yamaguchi, Takuhiro
Ueno, Ei
Hirokaga, Koichi
Tanaka, Kumiko
Article History
Received: 27 December 2018
Accepted: 19 September 2019
First Online: 26 October 2019
Compliance with ethical standards
:
: This article was written by the study investigators and is not associated with the promotion of any ultrasonic devices. The authors declare no conflicts of interest associated with this article.
: This retrospective observational study was approved by the institutional review board or ethics committee at each hospital or institution. Individual informed consent was not required. Data collection and analysis were performed by the Clinical Research, Innovation, and Education Center of Tohoku University Hospital. This study is registered as No. UMIN000007604.