1. Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
2. Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
3. Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
4. Department of Chemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
5. Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Florida, Gainesville, Florida 32610, United States
6. Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32610, United States