Volume 29, Issue 13 p. 1574-1581
Featured Article

7 tesla magnetic resonance imaging: A closer look at substantia nigra anatomy in Parkinson's disease

Stéphane Lehéricy MD, PhD

Corresponding Author

Stéphane Lehéricy MD, PhD

Institut du Cerveau et de la Moelle épinière—ICM, Centre de NeuroImagerie de Recherche—CENIR, Paris, France

Sorbonne Universités, UPMC Univ Paris 06, Paris, France

ICM Team Control of Normal and Abnormal Movement

Service de neuroradiologie, Groupe Hospitalier Pitié-Salpêtrière, Paris, France

Correspondence to: Stephane Lehéricy, Centre de NeuroImagerie de Recherche—CENIR, Institut du Cerveau et de la Moelle épinière—ICM, Hôpital Pitié-Salpêtrière, 47 bd de l'Hôpital, 75651 Paris Cedex 13, France, E-mail: [email protected]Search for more papers by this author
Eric Bardinet PhD

Eric Bardinet PhD

Institut du Cerveau et de la Moelle épinière—ICM, Centre de NeuroImagerie de Recherche—CENIR, Paris, France

Sorbonne Universités, UPMC Univ Paris 06, Paris, France

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Cyril Poupon PhD

Cyril Poupon PhD

CEA, NeuroSpin, Gif-sur-Yvette, France

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Marie Vidailhet MD

Marie Vidailhet MD

Sorbonne Universités, UPMC Univ Paris 06, Paris, France

ICM Team Control of Normal and Abnormal Movement

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Chantal François PhD

Chantal François PhD

Sorbonne Universités, UPMC Univ Paris 06, Paris, France

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First published: 12 October 2014
Citations: 104

Funding agencies: This study was supported by Agence Nationale de la Recherche, ‘Investissements d'avenir’ [grant number ANR-10-IAIHU-06] and Agence Nationale de la Recherche (ANRMNP 2009, Nucleipark), DHOS-Inserm, France Parkinson, Ecole Neuroscience de Paris.

Relevant conflicts of interest/financial disclosures: Nothing to report.

Author roles may be found in the online version of this article.

Abstract

A hallmark of Parkinson's disease (PD) is the progressive neurodegeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc). Dopaminergic denervation is commonly imaged using radiotracer imaging in target structures such as the striatum. Until recently, imaging made only a modest contribution to detecting neurodegenerative changes in the substantia nigra (SN) directly. Histologically, the SN is subdivided into the ventral pars reticulata and the dorsal pars compacta, which is composed of dopaminergic neurons. In humans, dopaminergic neurons, which are known to accumulate neuromelanin, form clusters of cells (nigrosomes) that penetrate deep into the SN pars reticulata (SNr). The SNr contains higher levels of iron than the SNc in normal subjects. Neuromelanin and T2*-weighted imaging therefore better detect the SNc and the SNr, respectively. The development of ultra-high field 7 Tesla (7T) magnetic resonance imaging (MRI) provided the increase in spatial resolution and in contrast that was needed to detect changes in SN morphology. 7T MRI allows visualization of nigrosome-1 as a hyperintense signal area on T2*-weighted images in the SNc of healthy subjects and its absence in PD patients, probably because of the loss of melanized neurons and the increase of iron deposition. This review is designed to provide a better understanding of the correspondence between the outlines and subdivisions of the SN detected using different MRI contrasts and the histological organization of the SN. The recent findings obtained at 7T will then be presented in relation to histological knowledge. © 2014 International Parkinson and Movement Disorder Society