Advanced MRI techniques bear great potential to explore myelination in hypomyelinating leukodystrophies such as Pelizaeus-Merzbacher disease (PMD) in-vivo. Quantitative imaging biomarkers which reflect myelin, its spatial distribution, and dynamics during brain maturation are not readily available i.e. to monitor natural disease courses. In a pilot study including three PMD patients, multi-component relaxation which enables the evaluation of relative myelination by estimating the myelin water fraction (MWF) was obtained from 56 region of interest (ROI). Determination of ROIs was facilitated by coregistration of the patients data to a pediatric atlas and compared to age matched healthy controls.