MRI Assessment of Basal Ganglia Iron Deposition in Parkinson's Disease

Purpose: To estimate the levels of basal ganglia iron levels in Parkinson's disease (PD) using the PRIME MR sequence at 3.0 Tesla, in relation to patients' motor symptom severity. Materials and Methods: Seventy patients with PD and 10 healthy controls underwent assessment of movement and MR imaging. Mean R(2)' relaxation rates were recorded in the substantia nigra, frontal white matter and In the rostral, mid, and caudal putamen. Results: R(2)' relaxation rates were significantly higher in patients with PD than in healthy controls. R(2)' in the most affected substantia nigra correlated with PD patients' motor symptom severity, but not with disease duration. Neuroradiological observation revealed a rostral to caudal "gradient" of putaminal hypointensity. This was substantiated by the finding that the mid and caudal putamen showed significantly higher R(2)' relaxation rates, consistent with higher iron levels in PD relative to the healthy controls. Conclusion: MRI at 3.0 Tesla suggests that substantia nigra iron levels are increased and linked to the severity of motor symptoms experienced in PD. Findings consistent with increased iron levels in the PD putamen are shown, in a region-specific rostral to caudal gradient.