1. Department of Nuclear Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
2. Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
3. Yale Center for Analytical Sciences, Yale School of Public Health, Yale University, New Haven, CT 06520, USA
4. Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35233, USA