Quantitative susceptibility mapping of the midbrain in Parkinson's disease. Issue 3 (12th September 2015)

• Record Type: Journal Article
• Authors: Du, Guangwei; Liu, Tian; Lewis, Mechelle M.; Kong, Lan; Wang, Yi; Connor, James; Mailman, Richard B.; Huang, Xuemei
• Is Part Of: Movement disorders. Volume 31:Issue 3(2016)
• Page Start: 317
• Page End: 324
• Publication Date: 2015-09-12
• Subjects: Parkinson's disease -- magnetic resonance imaging -- quantitative susceptibility mapping -- substantia nigra -- iron; Movement disorders -- Periodicals; 610
• DOI: 10.1002/mds.26417
• Languages: English
• ISSNs: 0885-3185

Abstract

Abstract: Background: Parkinson's disease (PD) is marked pathologically by dopamine neuron loss and iron overload in the substantia nigra pars compacta. Midbrain iron content is reported to be increased in PD based on magnetic resonance imaging (MRI) R2* changes. Because quantitative susceptibility mapping is a novel MRI approach to measure iron content, we compared it with R2* for assessing midbrain changes in PD. Methods: Quantitative susceptibility mapping and R2* maps were obtained from 47 PD patients and 47 healthy controls. Midbrain susceptibility and R2* values were analyzed by using both voxel‐based and region‐of‐interest approaches in normalized space, and analyzed along with clinical data, including disease duration, Unified Parkinson's Disease Rating Scale (UPDRS) I, II, and III subscores, and levodopa‐equivalent daily dosage. All studies were done while PD patients were "on drug." Results: Compared with controls, PD patients showed significantly increased susceptibility values in both right (cluster size = 106 mm 3 ) and left (164 mm 3 ) midbrain, located ventrolateral to the red nucleus that corresponded to the substantia nigra pars compacta. Susceptibility values in this region were correlated significantly with disease duration, UPDRS II, and levodopa‐equivalent daily dosage. Conversely, R2* was increased significantly only in a much smaller region (62 mm 3 ) of the left lateral substantia nigra pars compacta and was not significantly correlated with clinical parameters. Conclusion: The use of quantitative susceptibility mapping demonstrated marked nigral changes that correlated with clinical PD status more sensitively than R2*. These data suggest that quantitative susceptibility mapping may be a superior imaging biomarker to R2* for estimating brain iron levels in PD. © 2015 Movement Disorder Society