Quantitative Mapping of Substantia Nigra Iron in Parkinson's Disease (Stages I-IV, REM Sleep Behavior Disorder) and Controls

Prospective, single center study to determine whether the current R2\* iron mapping method for measuring nigral iron changes in the brain can be significantly improved by using the Quantitative Susceptibility Mapping (QSM) based iron mapping techniques with the goal of validating QSM for potential use in later clinical trials. Subjects with a diagnosis of Parkinson's Disease, Rapid Eye Movement (REM) Sleep Behavior Disorder, and Normal Volunteers who meet the inclusion and exclusion criteria will be eligible for participation in this study.