1. Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, 610041 Sichuan, China
2. Institute
for Nanobiomedical Technology and Membrane Biology, West China Hospital of Sichuan University, Chengdu, 610041 Sichuan, China
3. Laboratory of Stem
Cell Biology, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, 610041 Sichuan, China
4. Center for Biomedical
Engineering, NE47-379, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, United States