1. Department of Radiology, Center for Medical Imaging, State Key Laboratory of Biotherapy and Cancer Center West China Hospital, Sichuan University No. 17 People's South Road Chengdu 610041 China
2. Department of Materials Engineering, Graduate School of Engineering The University of Tokyo 7‐3‐1 Hongo, Bunkyo‐ku Tokyo 113‐8656 Japan
3. Institute for Future Initiatives The University of Tokyo 7‐3‐1 Hongo, Bunkyo‐ku Tokyo 113‐0033 Japan
4. Innovation Center of NanoMedicine Kawasaki Institute of Industrial Promotion 3‐25‐14, Tonomachi, Kawasaki‐ku Kawasaki 210‐0821 Japan
5. Department of Bioengineering, Graduate School of Engineering The University of Tokyo 7‐3‐1 Hongo, Bunkyo‐ku Tokyo 113‐8656 Japan