1Neuroradiology Department, Neurological Institute "Carlo Besta", IRCCS Foundation, Milan, Italy, 2Neuroimaging laboratory, IRCCS Santa Lucia Foundation, Rome, Italy, 3Division of Neurology V/Neuropathology, Neurological Institute "Carlo Besta", IRCCS Foundation, Milan, Italy, 4Laboratory of Alzheimer's Neuroimaging and Epidemiology, IRCCS Centro San Giovanni di Dio-FBF, Brescia, Italy, 5Memory Clinic and LANVIE-Laboratory of Neuroimaging of Aging, University Hospitals and University of Geneva, Geneva, Switzerland, 6Nuclear Medicine Unit, IRCCS San Raffaele Hospital, Milan, Italy, 7Department of Diagnostic Imaging, Neuroradiology Unit, University of Brescia, Brescia, Italy, 8Department of Neuroscience, Imaging and Clinical Sciences, University “G. d’Annunzio” of Chieti, Chieti, Italy, 9Institute for Advanced Biomedical Technologies (ITAB), University “G. d’Annunzio” of Chieti, Chieti, Italy, 10Neuroradiology Unit, Department of Diagnostic Imaging, R. Silvestrini Hospital, Perugia, Italy, 11Centre for Memory Disturbances, Lab of Clinical Neurochemistry, University of Perugia, Perugia, Italy, 12Department Health Professions - U.O.c Research and Development, Careggi University Hospital Florence, Florence, Italy, 13Department of Neuroradiology, Careggi University Hospital Florence, Florence, Italy, 14Medical Physics Unit, Spedali Civili di Brescia, Brescia, Italy, 15Section of Neurology, Center for Memory Disturbances, University of Perugia, Perugia, Italy, 16Scientific Direction, Neurological Institute "Carlo Besta", IRCCS Foundation, Milan, Italy, 17Center for Mind/Brain Sciences, University of Trento, Mattarello, Italy