1. Department of Nuclear Medicine Peking University First Hospital Beijing 100034 China
2. Departments of Radiology and Medical Physics University of Wisconsin – Madison Madison WI 53705 USA
3. Department of Pharmaceutical Sciences University of Wisconsin – Madison Madison WI 53705 USA
4. Department of Medical Molecular Biology Beijing Institute of Biotechnology Beijing 100850 China
5. Department of Nuclear Medicine Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430022 China