scholarly journals Magnetization transfer and adiabatic T1ρ MRI reveal abnormalities in normal-appearing white matter of subjects with multiple sclerosis

2013 ◽  
Vol 20 (8) ◽  
pp. 1066-1073 ◽  
Author(s):  
Silvia Mangia ◽  
Adam F Carpenter ◽  
Andy E Tyan ◽  
Lynn E Eberly ◽  
Michael Garwood ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Magnetization Transfer ◽  
Magnetic Resonance Images ◽  
Relaxation Methods ◽  
Normal Appearing White Matter ◽  
Relaxation Parameters ◽  
Relapsing Remitting ◽  
Cortical Gray Matter ◽  
The Brain

Background: Diffuse abnormalities are known to occur within the brain tissue of multiple sclerosis (MS) patients that is “normal appearing” on T1-weighted and T2-weighted magnetic resonance images. Objectives: With the goal of exploring the sensitivity of novel MRI parameters to detect such abnormalities, we implemented an inversion-prepared magnetization transfer (MT) protocol and adiabatic T1ρ and T2ρ rotating frame relaxation methods. Methods: Nine relapsing–remitting MS patients and seven healthy controls were recruited. Relaxation parameters were measured in a single slice just above the lateral ventricles and approximately parallel to the AC-PC line. Results: The MT ratio of regions encompassing the normal-appearing white matter (NAWM) was different in MS patients as compared with controls ( p = 0.043); however, the T1 measured during off-resonance irradiation (T1sat) was substantially more sensitive than the MT ratio for detecting differences between groups ( p = 0.0006). Adiabatic T1ρ was significantly prolonged in the NAWM of MS patents as compared to controls (by 6%, p = 0.026), while no differences were found among groups for T2ρ. No differences among groups were observed in the cortical gray matter for any relaxation parameter. Conclusions: The results suggest degenerative processes occurring in the NAWM of MS, likely not accompanied by significant abnormalities in iron content.

scholarly journals A tractometry investigation of white matter tract network structure and relationships with cognitive function in relapsing-remitting multiple sclerosis

2021 ◽  
Author(s):  
Danka Jandric ◽  
Geoff JM Parker ◽  
Hamied Haroon ◽  
Valentina Tomassini ◽  
Nils Muhlert ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Cognitive Function ◽  
White Matter ◽  
Cognitive Dysfunction ◽  
Network Structure ◽  
Test Performance ◽  
Cognitive Domains ◽  
Normal Appearing White Matter ◽  
Relapsing Remitting ◽  
The Brain

Understanding the brain changes underlying cognitive dysfunction is a key priority in multiple sclerosis to improve monitoring and treatment of this debilitating symptom. Functional connectivity network changes are associated with cognitive dysfunction, but it is less well understood how changes in normal appearing white matter relate to cognitive symptoms. If white matter tracts share a similar network structure it would be expected that tracts within a network are similarly affected by MS pathology. In the present study, we used a tractometry approach to explore patterns of variance in diffusion metrics across white matter (WM) tracts. We investigated whether separate networks, based on normal variation or pathology, appear, and how this relates to neuropsychological test performance across cognitive domains. A sample of 102 relapsing-remitting MS patients and 27 healthy controls underwent MRI and neuropsychological testing. Tractography was performed on diffusion MRI data to extract 40 WM tracts and microstructural measures were extracted from each tract. Principal component analysis (PCA) was used to decompose metrics from all tracts to assess the presence of any co-variance structure among the tracts. Similarly, PCA was applied to cognitive test scores to identify the main cognitive domains. Finally, we assessed the ability of tract components to predict test performance across cognitive domains. We found that a single component which captured pathology across all tracts explained the most variance and that there was little evidence for separate, smaller network patterns of pathology. WM tract components were weak, but significant, predictors of cognitive function in MS. These findings highlight the need to investigate the relationship between the normal appearing white matter and cognitive impairment further and on a more granular level, to improve the understanding of the network structure of the brain in MS.

Grey matter abnormalities in multiple sclerosis: proton magnetic resonance spectroscopic imaging

2001 ◽  
Vol 7 (4) ◽  
pp. 221-226 ◽  
Author(s):  
Rakesh Sharma ◽  
Ponnada A Narayana ◽  
Jerry S Wolinsky
Keyword(s):  
Multiple Sclerosis ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Magnetization Transfer ◽  
Spectroscopic Imaging ◽  
Magnetic Resonance Spectroscopic Imaging ◽  
Relapsing Remitting ◽  
Cortical Gray Matter ◽  
Magnetic Resonance Imaging Mri ◽  
Mri Characteristics

Pathologically defined abnormalities in the cortical gray matter (GM) are well described in multiple sclerosis (MS) but are infrequently seen by conventional magnetic resonance imaging (MRI). We systematically evaluated 52 relapsing - remitting MS patients and 20 normal volunteers with high resolution MRI and short echo proton magnetic resonance spectroscopic imaging (MRSI). Individual tissue contributions to the spectroscopic voxels were estimated based on MRI that incorporated both CSF suppression and magnetization transfer, or double inversion images in which both CSF and GM were suppressed. Strong resonances in the 0.8 to 1.5 p.p.m. spectral region were observed in 13 MS patients. Image segmentation based on the MRI characteristics of tissues contributing to the spectroscopic voxels showed that these additional peaks originated mainly from GM. The presence of these additional peaks suggests that the normal appearance GM on MRI, is biochemically abnormal in a substantial proportion of relapsing-remitting MS patients.

scholarly journals A higher proportion of ermin-immunopositive oligodendrocytes in areas of remyelination

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256155
Author(s):  
Intakhar Ahmad ◽  
Stig Wergeland ◽  
Eystein Oveland ◽  
Lars Bø
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Corpus Callosum ◽  
Mouse Model ◽  
Grey Matter ◽  
Early Stage ◽  
Relative Proportion ◽  
Normal Appearing White Matter ◽  
The Brain

Incomplete remyelination is frequent in multiple sclerosis (MS)-lesions, but there is no established marker for recent remyelination. We investigated the role of the oligodendrocyte/myelin protein ermin in de- and remyelination in the cuprizone (CPZ) mouse model, and in MS. The density of ermin+ oligodendrocytes in the brain was significantly decreased after one week of CPZ exposure (p < 0.02). The relative proportion of ermin+ cells compared to cells positive for the late-stage oligodendrocyte marker Nogo-A increased at the onset of remyelination in the corpus callosum (p < 0.02). The density of ermin-positive cells increased in the corpus callosum during the CPZ-phase of extensive remyelination (p < 0.0001). In MS, the density of ermin+ cells was higher in remyelinated lesion areas compared to non-remyelinated areas both in white- (p < 0.0001) and grey matter (p < 0.0001) and compared to normal-appearing white matter (p < 0.001). Ermin immunopositive cells in MS-lesions were not immunopositive for the early-stage oligodendrocyte markers O4 and O1, but a subpopulation was immunopositive for Nogo-A. The data suggest a relatively higher proportion of ermin immunopositivity in oligodendrocytes compared to Nogo-A indicates recent or ongoing remyelination.

Diffusion tensor imaging in multiple sclerosis: a tool for monitoring changes in normal-appearing white matter

2004 ◽  
Vol 10 (2) ◽  
pp. 188-196 ◽  
Author(s):  
Emmanuelle Cassol ◽  
Jean-Philippe Ranjeva ◽  
Danielle Ibarrola ◽  
Claude Mékies ◽  
Claude Manelfe ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Lesion Load ◽  
Normal Appearing White Matter ◽  
Relapsing Remitting ◽  
One Year ◽  
Diffusion Tensor Imaging Dti

Our objectives were to determine the reproducibility of diffusion tensor imaging (DTI) in volunteers and to evaluate the ability of the method to monitor longitudinal changes occurring in the normal-appearing white matter (NAWM) of patients with multiple sclerosis (MS). DTI was performed three-mo nthly for one year in seven MS patients: three relapsing-remitting (RRMS), three secondary progressive (SPMS) and one relapsing SP. They were selected with a limited cerebral lesion load. Seven age- and sex-matched controls also underwent monthly examinations for three months. Diffusivity and anisotropy were quantified over the segmented whole supratentorial white matter, with the indices of trace (Tr) and fractional anisotropy (FA). Results obtained in volunteers show the reproducibility of the method. Patients had higher trace and lower anisotropy than matched controls (P B-0.0001). O ver the follow-up, both Tr and FA indicated a recovery after the acute phase in RRMS and a progressive shift towards abnormal values in SPMS. A lthough this result is not statistically significant, it suggests that DTI is sensitive to microscopic changes occurring in tissue of normal appearance in conventional images and could be useful for monitoring the course of the disease, even though it was unable to clearly distinguish between the various physiopathological processes involved.

T1 relaxation maps allow differentiation between pathologic tissue subsets in relapsing-remitting and secondary progressive multiple sclerosis

2004 ◽  
Vol 10 (5) ◽  
pp. 556-561 ◽  
Author(s):  
A Castriota-Scanderbeg ◽  
F Fasano ◽  
M Filippi ◽  
C Caltagirone
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Relaxation Times ◽  
Brain Regions ◽  
Progressive Multiple Sclerosis ◽  
Clinical Group ◽  
Secondary Progressive ◽  
Normal Appearing White Matter ◽  
Relapsing Remitting ◽  
Normal White Matter

In an attempt to clarify whether T1 relaxation time mapping may assist in characterizing the pathological brain tissue substrate of multiple sclerosis (MS), we compared the T1 relaxation times of lesions, areas of normal-appearing white matter (NAWM) located proximal to lesions, and areas of NAWM located distant from lesions in 12 patients with the relapsing-remitting and 12 with the secondary progressive (SP) subtype of disease. Nine healthy volunteers served as controls. Calculated mean T1 values were averaged across all patients within each clinical group, and comparisons were made by means of the Mann-Whitney U-test. Significant differences were found between all investigated brain regions within each clinical subgroup. Significant differences were also detected for each investigated brain region among clinical subgroups. While T1 values of NAWM were significantly higher in patients with SP disease than in normal white matter (NWM) of controls, no differences were detected when corresponding brain areas of patients with RR MS were compared with NWM of controls. T1 maps identify areas of the brain that are damaged to a different extent in patients with MS, and may be of help in monitoring disease progression.

A Magnetization Transfer Imaging Study of Normal-Appearing White Matter in Multiple Sclerosis

Neurology ◽  
1995 ◽  
Vol 45 (3) ◽  
pp. 478-482 ◽  
Author(s):  
M. Filippi ◽  
A. Campi ◽  
V. Dousset ◽  
C. Baratti ◽  
V. Martinelli ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Magnetization Transfer ◽  
Imaging Study ◽  
Magnetization Transfer Imaging ◽  
Normal Appearing White Matter
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