1Electrical and Computer Engineering, The University of Arizona, Tucson, AZ, United States, 2Program in Applied Mathematics, the University of Arizona, Tucson, AZ, United States, 3Department of Medical Imaging, the University of Arizona, Tucson, AZ, United States, 4Electrical and Computer Engineering, the University of Arizona, Tucson, AZ, United States, 5Biomedical Engineering, the University of Arizona, Tucson, AZ, United States