1. School of Automation, Northwestern Polytechnical University, Xi’an, China
2. Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
3. School of Computer Science and Engineering, Xi’an University of Technology, Xi’an, China
4. Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA