Longitudinal Iron Changes in the Substantia Nigra of Early-Stage Parkinson's Disease.
BACKGROUND Progression of substantia nigra pars compacta (SNc) iron content in early-stage Parkinson's patients (PD) is poorly understood. OBJECTIVE To determine if nigral iron measured by quantitative susceptibility mapping (QSM) with zero-referencing can track disease progression in early-stage PD. METHODS Thi...