1. Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Room 2301, Building 149, Charlestown, Boston, Massachusetts 02129, United States
2. PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, United States
3. Department of Chemistry and Chemical Biology, University of California, Merced, Merced, California 95343, United States