1. Beijing Advanced Innovation Center for Soft Matter Science and Engineering College of Life Science and Technology Beijing University of Chemical Technology Beijing 100029 P. R. China
2. Department of Automatic Tsinghua University Peking University Third Hospital Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology Beijing 100191 P. R. China
3. Department of Radiology Peking University Third Hospital Institute of Medical Technology Peking University Health Science Center Beijing 100019 P. R. China