1Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2FM Kirby Research Center, Kennedy Krieger Institute, Baltimore, MD, United States, 3Department of Medical Radiation Physics, Lund University, Lund, Sweden, 4Department of Ultrasound, Guangzhou Panyu Central Hospital, Panyu, China, People's Republic of, 5Department of Neurology, Kennedy Krieger Institute, Baltimore, MD, United States, 6Department of Neuroscience, Kennedy Krieger Institute, Baltimore, MD, United States, 7Division of Cancer Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 8JHU In Vivo Cellular Molecular Imaging Center, Baltimore, MD, United States