1Physics and Geology Department, University of Perugia, Perugia, Italy, 2Medical Physics Department, Santa Maria della Misericordia Hospital, Perugia, Italy, 3Division of Neurology V/Neuropathology, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy, 4Laboratory of Alzheimer's Neuroimaging and Epidemiology, IRCCS Fatebenefratelli, Brescia, Italy, 5Memory Clinic and LANVIE-Laboratory of Neuroimaging of Aging, University Hospitals and University of Geneva, Geneva, Switzerland, 6Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy, 7Neuroimaging laboratory, IRCCS Santa Lucia Foundation, Rome, Italy, 8Vita-Salute San Raffaele University, Milan, Italy, 9Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy, 10University of Brescia, Brescia, Italy, 11Department of Neuroscience, Imaging and Clinical Sciences, University “G. d’Annunzio” of Chieti, Chieti, Italy, 12Institute for Advanced Biomedical Technologies (ITAB), University “G. d’Annunzio” of Chieti, Chieti, Italy, 13Centre for Memory Disturbances, Lab of Clinical Neurochemistry, University of Perugia, Perugia, Italy, 14Department of Health Professions - U.O.c Research and Development, Careggi University Hospital, Florence, Italy, 15Department of Neuroradiology, Careggi University Hospital, Florence, Italy, 16Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy, 17Neuroradiology Unit, University of Brescia, Brescia, Italy, 18Medical Physics Unit, Spedali Civili di Brescia, Brescia, Italy, 19Scientific Direction, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy, 20CIMEC - Center for Mind/Brain Sciences, University of Trento, Trento, Italy