There is increasing evidence that myelin can be directly involved in Parkinson's disease (PD). We investigated the utility of ViSTa myelin water imaging (MWI) to characterize changes in myelination in PD. Slight decrease of global white matter myelin water fraction (MWF) was observed in PD patients. MWF was also associated with cognitive status, while no such association was found between DTI metrics and cognitive status. These indicated that MWF may potentially be a more specific biomarker for dysmyelination in the brain.