1. Shanghai Universal Medical Imaging Diagnostic Center, Shanghai 200233, China.
2. Department of Radiology, PET/CT Center, Shanghai 85 Hospital, Shanghai 200052, China.
3. Department of Radiology, affiliated Changzheng Hospital, The Second Military Medical University, Shanghai 200003, China.
4. Department of Chemoradiotherapy, Yinzhou People's Hospital, Ningbo 315100, China.