1. School of Physics Huazhong University of Science and Technology Wuhan 430074China
2. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics National Center for Magnetic Resonance in Wuhan Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071China
3. Department of Magnetic Resonance Imaging Zhongnan Hospital of Wuhan University Wuhan 430071 China