In this issue of , guest editors Drs. Frederik Barkhof and Yaou Liu bring their considerable expertise to the topic of . Top experts in the field discuss advanced brain imaging in CNS demyelinating diseases; new imaging markers in MS and related disorders: smoldering inflammation and central vein sign; the use of AI in MS and white matter disease; optic nerve imaging in MS and related disorders; atypical demyelinating disorders; and more. Co-Editor Frederik Barkhof, MD, has received the National Multiple Sclerosis Society and the American Academy of Neurology’s 2018 John Dystel Prize for Multiple Sclerosis Research for his many years of outstanding research in the field of MS, especially in advancing the understanding and clinical use of brain imaging.