School of Automation, Northwestern Polytechnical University, Xian, China. Contact:Li Shen: shenli@iu.edu and Lei Du: dulei@nwpu.edu.cn .|Department of Radiology and Imaging Sciences, Indiana University School of Medicine,IN, USA.|School of Automation, Northwestern Polytechnical University, Xian, China. Contact:Li Shen: shenli@iu.edu and Lei Du: dulei@nwpu.edu.cn .|Department of Radiology and Imaging Sciences, Indiana University School of Medicine,IN, USA.|Department of Radiology and Imaging Sciences, Indiana University School of Medicine,IN, USA.|Department of Radiology and Imaging Sciences, Indiana University School of Medicine,IN, USA.|School of Automation, Northwestern Polytechnical University, Xian, China. Contact:Li Shen: shenli@iu.edu and Lei Du: dulei@nwpu.edu.cn .|School of Automation, Northwestern Polytechnical University, Xian, China. Contact:Li Shen: shenli@iu.edu and Lei Du: dulei@nwpu.edu.cn .|Department of Radiology and Imaging Sciences, Indiana University School of Medicine,IN, USA.|Department of Radiology and Imaging Sciences, Indiana University School of Medicine,IN, USA.|Department of Radiology and Imaging Sciences, Indiana University School of Medicine,IN, USA.