in brain myelination with age and sex have been the subject of intense MRI study.
However, most studies have used nonspecific methods to probe myelin, including DTI
and relaxation times. We investigated age- and sex-related differences in brain
myelin water fraction (MWF), a surrogate of myelin content, in a large cohort
of unimpaired participants, spanning a wide age range. We observed a quadratic relationship
between MWF and age in all brain regions investigated, suggesting that
myelination continues until middle age followed by a decrease through older age. Sexual dimorphism in this process was
observed in several brain regions.