1. Department of Radiology; First Hospital of Shanxi Medical University; Taiyuan 030001 China
2. Molecular Imaging Program at Stanford (MIPS); Canary Center at Stanford for Cancer Early Detection; Department of Radiology and Bio-X Program; School of Medicine; Stanford University; Stanford CA 94305-5484 USA
3. Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials; Nanjing University of Posts and Telecommunications; Nanjing 210023 China
4. Key Laboratory of Nuclear Medicine; Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine; Jiangsu Institute of Nuclear Medicine; Wuxi 214063 China