Reproducible detection of nigral iron deposition in 2 Parkinson's disease cohorts

• Authors: Jason Langley, University of California Riverside; Naying He, Shanghai Jiao Tong University; Daniel Huddleston, Emory University; Shengdi Chen, Shanghai Jiao Tong University; Fuhua Yan, Shanghai Jiao Tong University; Bruce Crosson, Emory University; Stewart Factor, Emory University; Xiaoping Hu, Emory University
• Journal Title: Movement Disorders
• Volume: Volume 34, Number 3
• Publisher: Wiley-Liss | 2019-03-01, Pages 416-420
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1002/mds.27608
• Subjects: Health Sciences, Pathology; Biology, Neuroscience; Health Sciences, Radiology; Health Sciences, Rehabilitation and Therapy
• Keywords: Science & Technology; Life Sciences & Biomedicine; Clinical Neurology; Neurosciences & Neurology; iron; MRI; neuromelanin; Parkinson's disease; substantia nigra pars compacta; Substantia nigra; Brain; Diagnosis; Degeneration; Pathology; T1

Abstract

Background: Previous studies investigating nigral iron accumulation used T 2 or T 2 *-weighted contrasts to define the regions of interest (ROIs) in the substantia nigra with mixed results. Because these contrasts are not sensitive to neuromelanin, ROIs may have inadvertently missed the SNpc. An approach sensitive to neuromelanin should yield consistent results. We examine iron deposition in ROIs derived from neuromelanin-sensitive and T 2 *-weighted contrasts, respectively. Methods: T 1 -weighted and multiecho gradient echo imaging data were obtained in 2 cohorts. Multiecho gradient echo imaging data were analyzed using neuromelanin-sensitive SNpc ROIs as well as T 2 *-weighted SNr ROIs. Results: When compared with controls, significantly larger R 2 * values were seen in the SNpc of PD patients in both cohorts. Mean R 2 * values in the SNr of PD patients showed no consistency, with 1 cohort showing a small, statistically significant increase, whereas the other cohort exhibited no statistical difference. Conclusion: Mean R 2 * in the SNpc defined by neuromelanin-sensitive MRI is significantly increased in PD.