Quantitative assessment of brain iron by R(2)* relaxometry in patients with clinically isolated syndrome and relapsing-remitting multiple sclerosis.
BACKGROUND
Increased iron deposition has been implicated in the pathophysiology of multiple sclerosis (MS), based on visual analysis of signal reduction on T(2)-weighted images. R(2)* relaxometry allows to assess brain iron accumulation quantitatively.


OBJECTIVE
To investigate regional brain iron deposition in patients with a clinically isolated syndrome (CIS) or relapsing-remitting MS (RRMS) and its associations with demographical, clinical, and conventional magnetic resonance imaging (MRI) parameters.


METHODS
We studied 69 patients (CIS, n = 32; RRMS, n = 37) with 3T MRI and analyzed regional R(2)* relaxation rates and their correlations with age, disease duration, disability, T(2) lesion load, and normalized brain volumes.


RESULTS
Basal ganglia R(2)* relaxation rates increased in parallel with age (r = 0.3-0.6; P < 0.01) and were significantly higher in RRMS than in CIS (P < 0.05). Using multivariate linear regression analysis, the rate of putaminal iron deposition was independently predicted by the patients' age, disease duration, and gray matter atrophy.


CONCLUSIONS
Quantitative assessment by R(2)* relaxometry suggests increased iron deposition in the basal ganglia of MS patients, which is associated with disease duration and brain atrophy. This technique together with long-term follow-up thus appears suited to clarify whether regional iron accumulation contributes to MS morbidity or merely reflects an epiphenomenon.
Khalil
M
M
Department of Neurology and Department of Radiology (Division of Neuroradiology), Medical University of Graz, Graz, Austria.
Enzinger
C
C
Langkammer
C
C
Tscherner
M
M
Wallner-Blazek
M
M
Jehna
M
M
Ropele
S
S
Fuchs
S
S
Fazekas
F
F
D000328:Adult; D001284:Atrophy; D001479:Basal Ganglia / Q000378:metabolism* / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods; D001933:Brain Stem / Q000378:metabolism / Q000473:pathology; D003711:Demyelinating Diseases / Q000378:metabolism / Q000473:pathology; D005260:Female; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000378:metabolism* / Q000473:pathology*; D013788:Thalamus / Q000378:metabolism / Q000473:pathology; D055815:Young Adult
D007501:Iron