1Telecommunications Engineering, University of Maryland-College Park, College Park, MD, United States, 2Translational Imaging Biomarkers, Merck Research Laboratories, West Point, PA, United States, 3Translational Imaging Biomarkers, Merck Research Laboratories, Kenilworth, NJ, United States, 4Pharmacokinetics, Merck Research Laboratories, Rahway, NJ, United States, 5Biogen, Inc., Cambridge, MA, United States