1. The Key Laboratory of Biomedical Information Engineering of Ministry of Education School of Life Science and Technology Xi'an Jiaotong University Xi'an 710049 P. R. China
2. Henan Key laboratory of Functional Magnetic Resonance Imaging and Molecular Imaging Department of MRI The First Affiliated Hospital of Zhengzhou University Zhengzhou 450000 P. R. China
3. School of Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA
4. John A. Paulson School of Engineering and Applied Sciences Harvard University Cambridge MA 02138 USA
5. Department of Epidemiology Shaanxi Provincial Tumor Hospital Xi'an 710061 P. R. China
6. Research Center of Life Science Research Institute of Xi'an Jiaotong University Zhejiang 311200 P. R. China