1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 3MRI Center “SUN-FISM”, Second University of Naples and Institute of Diagnosis and Care “Hermitage-Capodimonte, Naples, Italy, 4I Division of Neurology, Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Second University of Naples, Naples, Italy, 5Department of Neurological and Behavioral Sciences, University of Siena, Siena, Italy, 6Department of Radiology and Nuclear Medicine, MS Centre Amsterdam, VU University Medical Centre, Amsterdam, Netherlands, 7NMR Research Unit, Queen Square MS Centre, UCL Institute of Neurology, London, United Kingdom, 8Department of Neurology, Medical University of Graz, Graz, Austria