Magnetic Resonance Phase Alterations in Multiple Sclerosis Patients with Short and Long Disease Duration
July
Magnetic Resonance Phase Alterations in Multiple Sclerosis Patients with Short and Long Disease Duration
Ivan Bozin 0 1 2
Yulin Ge 0 1 2
Joseph Kuchling 0 1 2
Petr Dusek 0 1 2
Sanjeev Chawla 0 1 2
Lutz Harms 0 1 2
Klemens Ruprecht 0 1 2
Thoralf Niendorf 0 1 2
Friedemann Paul 0 1 2
Ilya Kister 0 1 2
Tim Sinnecker 0 1 2
Jens Wuerfel 0 1 2
0 1 NeuroCure Clinical Research Center, Charité -Universitaetsmedizin Berlin , Berlin, Germany , 2 Department of Radiology, NYU School of Medicine , New York , New York, United States of America, 3 Institute of Neuroradiology, Universitaetsmedizin Goettingen , Goettingen, Germany , 4 Department of Neurology and Center of Clinical Neuroscience, Charles University in Prague, 1st Faculty of Medicine and General University Hospital in Prague , Prague , Czech Republic , 5 Clinical and Experimental Multiple Sclerosis Research Center, Charité Universitaetsmedizin Berlin , Berlin, Germany , 6 Department of Neurology, Charité-Universitaetsmedizin Berlin , Berlin, Germany, 7 Berlin Ultrahigh Field Facility , Max Delbrueck Center for Molecular Medicine , Berlin, Germany , 8 Experimental and Clinical Research Center, Charité-Universitaetsmedizin Berlin and Max Delbrueck Center for Molecular Medicine , Berlin, Germany , 9 Multiple Sclerosis Care Center, Department of Neurology, NYU School of Medicine , New York , New York, United States of America, 10 Department of Neurology, Asklepios Fachklinikum Teupitz , Teupitz , Germany
1 Funding: This work was supported by the German Research Foundation (DFG Exc 257 to F.P.) and by the German Ministry of Education and Research (Competence Network Multiple Sclerosis KKNMS to F.P. and J.W.) and a research grant from the Guthy Jackson Charitable Foundation/the National Multiple Sclerosis Society of the USA , F.P. and J.W.
2 Editor: Yi Wang, Cornell University , UNITED STATES
The analysis of the MR phase provides additional information on the tissue microstructure.
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Competing Interests: The authors have declared
that no competing interests exist.
In multiple sclerosis (MS) lesions phase alterations may reflect different stages of
inflammatory activity. Here we investigated lesion morphology in MS patients with short and long
disease duration on T2* weighted, phase, magnitude and susceptibility weighted imaging
17 MS or clinically isolated syndrome patients with short (<60 months) and 11 with long
(>60 months) disease duration underwent 7T MRI. Lesions were subsequently analyzed
side-by-side with regard to morphology and visibility on T2* weighted, SWI, magnitude and
126 of 192 T2* weighted lesions (65.6%) were characterized by a phase alteration pattern,
and hence could be differentiated on phase images. In detail, a significantly reduced
proportion of lesions showing phase alterations was detectable in patients with longer disease
duration (mean±SD 51±37%, range 0–100%) compared to patients with short disease
duration (mean±SD 90±19.5%, range 50–100%, p = 0.003).
This cross-sectional study identified different patterns of phase changes in lesions of MS
patients with short and long standing disease. Longitudinal studies are warranted to prove
that MR phase imaging is useful in determining the activity and the developmental stage of
individual MS plaques.
Multiple Sclerosis (MS) is an inflammatory, demyelinating and neurodegenerative central
nervous system disease [1]. Magnetic resonance imaging (MRI) improved early MS diagnosis
by demonstrating spatiotemporal lesion dissemination. However, conventional MR parameters
are not specific for MS, and correlate moderately with clinical disability—a phenomenon
termed “clinico-radiological paradox” [2]. Today, ultrahigh field MRI at 7 Tesla (T) visualizes
focal MS lesions in great detail [3–5]. Gaining from increased signal to noise ratio and
enhanced susceptibility effects, MS lesions on 7T T2 weighted (T2 w) images frequently
display a small central vein. A proportion of lesions also exhibits a hypointense rim. Both
characteristics can be used to distinguish MS from other white-matter pathologies such as
neuromyelitis optica [5], Susac syndrome [6], and white matter lesions of presumably vascular origin
[7,8], which consequently improves the diagnosis of MS [9].
Early reports [9–11] suggested that the T2 hypointense rim surrounding MS plaques is
caused by microglia and macrophages containing iron—a paramagnetic metal involved in
(repair-) processes that are abnormal within the MS brain [12]. However, the underlying
pathomechanism causing susceptibility related signal loss at the edges of such lesions in T2 w
MRI is still not fully understood. Recently, rim-like phase abnormalities in MS lesions were
correlated with increased inflammatory activity of the evolving MS plaque [13].
Susceptibility induced magnetic resonance (MR) phase alterations may contain additional
information on tissue microstructure [14], exceeding alterations in MR signal magnitude.
However, the MR phase of the white matt (...truncated)