1 Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, CB#7513, Chapel Hill, NC 27599, USA. Electronic address: weili_lin@med.unc.edu.
2 Department of Radiology, Taipei Veterans General Hospital, Taipei 11217, Taiwan. Electronic address: hsz829@gmail.com.
3 Department of Radiology, Neuroradiology Section, University of North Carolina School of Medicine, CB#7510, 511 Old Infirmary, Chapel Hill, NC 27599, USA. Electronic address: leey@med.unc.edu.
4 Division of Nuclear Medicine, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, CB #7510, Physicians Office Building, B119, Chapel Hill, NC 27599-7510, USA. Electronic address: tzwong@med.unc.edu.