1CMRR, Department of Radiology, University of Minnesota, Minneapolis, MN, United States, 2Department of Physics, University of Sao Paulo, Ribeirao Preto, Brazil, 3School of Kinesiology, University of Minnesota, Minneapolis, MN, United States, 4Central European Institute of Technology, Masaryk University, Brno, Czech Republic, 5Department of Medicine, University of Minnesota, Minneapolis, MN, United States, 6Division of Biostatistics, University of Minnesota, Minneapolis, MN, United States