1Laboratory of Functional and Metabolic Imaging (LIFMET), Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, 3Department of Radiology, University of Geneva (UNIGE), Geneva, Switzerland, 4Department of Radiology, University of Lausanne (Unil), Lausanne, Switzerland