Funding for this research was provided by:
National Basic Research Program of China (973 Program) (2016YFC0100500)
Text and Data Mining valid from 2018-11-02
Received: 23 October 2018
Accepted: 30 October 2018
First Online: 2 November 2018
Compliance with ethical standards
: S Tu received research support from Medis medical imaging and Pulse medical imaging technology. Other authors report no conflicts of interest in relation to this study.