Quantitative Susceptibility Mapping in Parkinson's Disease.
BACKGROUND
Quantitative susceptibility mapping (QSM) and R2* relaxation rate mapping have demonstrated increased iron deposition in the substantia nigra of patients with idiopathic Parkinson's disease (PD). However, the findings in other subcortical deep gray matter nuclei are converse and the sensitivity of QSM and R2* for morphological changes and their relation to clinical measures of disease severity has so far been investigated only sparsely.


METHODS
The local ethics committee approved this study and all subjects gave written informed consent. 66 patients with idiopathic Parkinson's disease and 58 control subjects underwent quantitative MRI at 3T. Susceptibility and R2* maps were reconstructed from a spoiled multi-echo 3D gradient echo sequence. Mean susceptibilities and R2* rates were measured in subcortical deep gray matter nuclei and compared between patients with PD and controls as well as related to clinical variables.


RESULTS
Compared to control subjects, patients with PD had increased R2* values in the substantia nigra. QSM also showed higher susceptibilities in patients with PD in substantia nigra, in the nucleus ruber, thalamus, and globus pallidus. Magnetic susceptibility of several of these structures was correlated with the levodopa-equivalent daily dose (LEDD) and clinical markers of motor and non-motor disease severity (total MDS-UPDRS, MDS-UPDRS-I and II). Disease severity as assessed by the Hoehn & Yahr scale was correlated with magnetic susceptibility in the substantia nigra.


CONCLUSIONS
The established finding of higher R2* rates in the substantia nigra was extended by QSM showing superior sensitivity for PD-related tissue changes in nigrostriatal dopaminergic pathways. QSM additionally reflected the levodopa-dosage and disease severity. These results suggest a more widespread pathologic involvement and QSM as a novel means for its investigation, more sensitive than current MRI techniques.
Department of Neurology, Medical University of Graz, Graz, Austria.
Christian
http://orcid.org/0000-0002-7097-9707
C
Langkammer
Department of Neurology, Medical University of Graz, Graz, Austria.
Lukas
L
Pirpamer
Department of Neurology, Medical University of Graz, Graz, Austria.
Stephan
S
Seiler
Medical Physics Group, University Hospital-Friedrich Schiller University Jena, Jena, Germany.
Andreas
A
Deistung
Buffalo Neuroimaging Analysis Center, Department of Neurology, University at Buffalo, The State University of New York, Buffalo, NY, United States of America.|MRI Molecular and Translational Imaging Center, Clinical and Translational Research Center, University at Buffalo, The State University of New York, Buffalo, NY, United States of America.
Ferdinand
F
Schweser
Department of Neurology, Medical University of Graz, Graz, Austria.
Sebastian
S
Franthal
Department of Neurology, Medical University of Graz, Graz, Austria.
Nina
N
Homayoon
Department of Neurology, Medical University of Graz, Graz, Austria.
Petra
P
Katschnig-Winter
Department of Neurology, Medical University of Graz, Graz, Austria.
Mariella
M
Koegl-Wallner
Department of Neurology, Medical University of Graz, Graz, Austria.
Tamara
T
Pendl
Department of Neurology, Medical University of Graz, Graz, Austria.
Eva Maria
EM
Stoegerer
Department of Neurology, Medical University of Graz, Graz, Austria.
Karoline
K
Wenzel
Department of Neurology, Medical University of Graz, Graz, Austria.
Franz
F
Fazekas
Department of Neurology, Medical University of Graz, Graz, Austria.
Stefan
S
Ropele
Medical Physics Group, University Hospital-Friedrich Schiller University Jena, Jena, Germany.|Michael Stifel Center for Data-driven and Simulation Science Jena, Friedrich Schiller University Jena, Jena, Germany.
Jürgen Rainer
JR
Reichenbach
Department of Neurology, Medical University of Graz, Graz, Austria.
Reinhold
R
Schmidt
Department of Neurology, Medical University of Graz, Graz, Austria.|Division of Neuroradiology, Department of Radiology, Medical University of Graz, Graz, Austria.
Petra
P
Schwingenschuh
D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D001931:Brain Mapping / Q000379:methods*; D016022:Case-Control Studies; D005260:Female; D005917:Globus Pallidus / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007501:Iron / Q000378:metabolism; D007980:Levodopa / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D012012:Red Nucleus / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D012720:Severity of Illness Index; D013378:Substantia Nigra / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D013788:Thalamus / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
D000978:Antiparkinson Agents; D007980:Levodopa; D007501:Iron