7-T Neuromelanin and R2* MRI in Parkinson Disease.

Abstract

HomeRadiologyVol. 305, No. 2 PreviousNext Reviews and CommentaryFree AccessImages in Radiology7-T Neuromelanin and R2* MRI in Parkinson DiseaseDhairya A. Lakhani, Erik H. Middlebrooks Dhairya A. Lakhani, Erik H. Middlebrooks Author AffiliationsFrom the Department of Radiology, West Virginia University, Morgantown, W.Va. (D.A.L.); and Department of Radiology, Mayo Clinic College of Medicine and Science, 4500 San Pablo Rd, Jacksonville, FL 32224 (E.H.M.).Address correspondence to E.H.M. (email: [email protected]).Dhairya A. LakhaniErik H. Middlebrooks Published Online:Aug 2 2022https://doi.org/10.1148/radiol.220230MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In A 76-year-old man presented with worsening balance, shuffling gait, and right-hand tremor, beginning 3 years before evaluation. On examination, he had reduced facial expressions, reduced blink rate, and hypophonic voice. His gait was slow and shuffling, with bilateral reduced arm swing. He also had rigidity and bradykinesia in all four extremities, greater on the right. His examination features were typical of the akinetic-rigid subtype of Parkinson disease (PD). He underwent brain MRI to support the diagnosis and to assess for other etiologies, such as an atypical parkinsonian syndrome.In this case, we used a high-spatial-resolution multiecho gradient-echo sequence with magnetization transfer pulse at 7 T to image neuromelanin in the substantia nigra, which normally has a high concentration of neuromelanin-rich cells. Neuromelanin imaging stands to benefit from 7-T MRI due to higher signal-to-noise ratio, tissue contrast, and spatial resolution. Reduced size and signal intensity of the substantia nigra were consistent with PD (Figure). Additionally, the multiecho sequence allowed for the quantification of the R2*, which reveals elevated iron deposition in this case, another histopathologic feature of PD (Figure). The combination of both biomarkers has potential to be a powerful tool for diagnosis and monitoring progression of PD.Images in a 76-year-old man with akinetic-rigid subtype Parkinson disease (PD) with symptoms greater on the right side. (A) Axial neuromelanin-sensitive MRI scan derived from rigid subtype PD shows reduced size and signal intensity of the substantia nigra (SN) (arrows) on the first echo image of a neuromelanin-sensitive three-dimensional multiecho fast low-angle shot, or FLASH, MRI scan with magnetization transfer pulse (7-T Siemens MAGNETOM Terra [Siemens Healthineers]; repetition time, 52 m/sec; echo time, 2.18, 4.15, and 7.09 m/sec; section thickness, 1.5 mm; flip angle, 16°; averages, 1; interpolated voxel size, 0.4 × 0.4 × 1.5 mm; acquisition time, 10 minutes and19 seconds). (B) MRI scan in a 73-year-old woman with the diagnosis of essential tremor is shown for illustration of the normal appearance of the substantia nigra (arrows) as comparison. (C) Plot graph of the substantia-nigra signal intensity (normalized by the adjacent cerebral-peduncle signal intensity) over the three echoes shows decreased neuromelanin in the patient with PD (greater decrease in the left substantia nigra) on the first echo neuromelanin-sensitive image. There is also a more rapid decrease in signal intensity over the second and third echoes, reflecting increased R2* effect from elevated iron deposition.Download as PowerPointOpen in Image Viewer Disclosures of conflicts of interest: D.A.L. No relevant relationships. E.H.M. Clinical trial and research funding paid to institution by Varian Medical Systems and Boston Scientific; unrelated consultant fees from Boston Scientific.Article HistoryReceived: Feb 1 2022Revision requested: Mar 7 2022Revision received: Mar 15 2022Accepted: Mar 18 2022Published online: Aug 02 2022Published in print: Nov 2022 FiguresReferencesRelatedDetailsRecommended Articles Substantia Nigra Volumetry with 3-T MRI in De Novo and Advanced Parkinson DiseaseRadiology2020Volume: 296Issue: 2pp. 401-410Differential Effect of Iron and Myelin on Susceptibility MRI in the Substantia NigraRadiology2021Volume: 301Issue: 3pp. 682-691High-Spatial-Resolution Diffusion MRI in Parkinson Disease: Lateral Asymmetry of the Substantia NigraRadiology2019Volume: 291Issue: 1pp. 149-157Imaging the Substantia Nigra in Parkinson Disease and Other Parkinsonian SyndromesRadiology2021Volume: 300Issue: 2pp. 260-278Is High-Spatial-Resolution Diffusion MRI Applicable for the Diagnosis of Parkinson Disease?Radiology2019Volume: 292Issue: 1pp. 267-268See More RSNA Education Exhibits Parkinsonian Syndromes: The Past, Present, and FutureDigital Posters2019Contemporary MRI Imaging in Parkinson's DiseaseDigital Posters2019The Role of MR-guided Focused Ultrasound as a Symptomatic Treatment for Parkinson's Disease: Behind and BeyondDigital Posters2020 RSNA Case Collection Primary HemochromatosisRSNA Case Collection2021NeuroferritinopathyRSNA Case Collection2021Multiple System Atrophy (MSA)RSNA Case Collection2021 Vol. 305, No. 2 Metrics Altmetric Score PDF download