Jason Plemel, PhD, University of Alberta, Edmonton, AB, Canada, comments on various quantitative methods to measure myelination. Whilst electron microscopy is frequently used in animal models, MRI-based techniques including diffusion tensor imaging (DTI) and myelin volume fraction imaging are utilized more in a clinical setting. Despite the prevalence of such techniques, they do not directly measure myelination and instead measure water movement in the brain and subsequently other changes. Dr Plemel emphasizes the need to have readouts specific to myelination, especially when novel therapies are assessed based on such biomarkers. This interview took place at the ACTRIMS Forum 2022 in West Palm Beach, Florida.