1. The Key Lab of Optoelectronic Technology and Systems of the Education Ministry of China, Chongqing University, Chongqing, China
2. Biomedical Imaging Division, VT-WFU School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA, USA
3. Department of Radiology, Division of Radiologic Sciences, Wake Forest University Health Sciences, Winston-Salem, NC, USA
4. Biomedical Imaging Division, VT-WFU School of Biomedical Engineering and Sciences, Wake Forest University Health Sciences, Winston-Salem, NC, USA
5. Department of Radiology, University of Otago, Christchurch, New Zealand
6. Department of Physics and Astronomy, University of Canterbury, Christchurch, New Zealand
7. European Organization for Nuclear Research, Geneva, Switzerland