scholarly journals Restriction spectrum imaging of white matter and its relation to neurological disability in multiple sclerosis

2018 ◽  
Vol 25 (5) ◽  
pp. 687-698 ◽  
Author(s):  
Piotr Sowa ◽  
Hanne F Harbo ◽  
Nathan S White ◽  
Elisabeth G Celius ◽  
Hauke Bartsch ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Free Water ◽  
White Matter Lesions ◽  
Neurological Disability ◽  
Water Fraction ◽  
Neurite Density ◽  
Normal Appearing White Matter ◽  
Spectrum Imaging

Background: Restriction spectrum imaging (RSI) is a recently introduced magnetic resonance imaging diffusion technique. The utility of RSI in multiple sclerosis (MS) is unknown. Objective: To investigate the association between RSI-derived parameters and neurological disability in MS. Methods: Seventy-seven relapsing–remitting MS patients were scanned with RSI on a 3-T scanner. RSI-derived parameters: fast and slow apparent diffusion coefficient (sADC), fractional anisotropy, restricted fractional anisotropy, neurite density (ND), cellularity, extracellular water fraction, and free water fraction, were obtained in white matter lesions (WML) and normal appearing white matter (NAWM). Patients were divided into three groups according to their expanded disability status scale (EDSS): with minimal, low, and substantial disability (<2.5, 2.5–3, and >3, respectively). Group comparisons and correlation analyses were performed. Results: All tested RSI-derived parameters differed between WML and NAWM ( p < 0.001 for all pairwise comparisons). The sADC in WML showed largest difference across disability subgroups (analysis of variance (ANOVA): F = 5.1, η2 = 0.12, p = 0.008). ND in NAWM showed strongest correlation with disability (ϱ = –0.39, p < 0.001). Conclusion: The strongest correlation with EDSS of ND obtained in NAWM indicates that processes outside lesions are important for disability in MS. Our study suggests that RSI-derived parameters may help understand the “clinico-radiological paradox” and improve disease monitoring in MS.

Non-invasive quantification of inflammation, axonal and myelin injury in multiple sclerosis

Brain ◽  
2020 ◽  
Author(s):  
Simona Schiavi ◽  
Maria Petracca ◽  
Peng Sun ◽  
Lazar Fleysher ◽  
Sirio Cocozza ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Black Holes ◽  
White Matter ◽  
Corpus Callosum ◽  
Fractional Anisotropy ◽  
White Matter Lesions ◽  
Healthy Controls ◽  
Normal Appearing White Matter ◽  
Relapsing Remitting ◽  
Spectrum Imaging

Abstract The aim of this study was to determine the feasibility of diffusion basis spectrum imaging in multiple sclerosis at 7 T and to investigate the pathological substrates of tissue damage in lesions and normal-appearing white matter. To this end, 43 patients with multiple sclerosis (24 relapsing-remitting, 19 progressive), and 21 healthy control subjects were enrolled. White matter lesions were classified in T1-isointense, T1-hypointense and black holes. Mean values of diffusion basis spectrum imaging metrics (fibres, restricted and non-restricted fractions, axial and radial diffusivities and fractional anisotropy) were measured from whole brain white matter lesions and from both lesions and normal appearing white matter of the corpus callosum. Significant differences were found between T1-isointense and black holes (P ranging from 0.005 to &lt;0.001) and between lesions’ centre and rim (P &lt; 0.001) for all the metrics. When comparing the three subject groups in terms of metrics derived from corpus callosum normal appearing white matter and T2-hyperintense lesions, a significant difference was found between healthy controls and relapsing-remitting patients for all metrics except restricted fraction and fractional anisotropy; between healthy controls and progressive patients for all metrics except restricted fraction and between relapsing-remitting and progressive multiple sclerosis patients for all metrics except fibres and restricted fractions (P ranging from 0.05 to &lt;0.001 for all). Significant associations were found between corpus callosum normal-appearing white matter fibres fraction/non-restricted fraction and the Symbol Digit Modality Test (respectively, r = 0.35, P = 0.043; r = −0.35, P = 0.046), and between black holes radial diffusivity and Expanded Disability Status Score (r = 0.59, P = 0.002). We showed the feasibility of diffusion basis spectrum imaging metrics at 7 T, confirmed the role of the derived metrics in the characterization of lesions and normal appearing white matter tissue in different stages of the disease and demonstrated their clinical relevance. Thus, suggesting that diffusion basis spectrum imaging is a promising tool to investigate multiple sclerosis pathophysiology, monitor disease progression and treatment response.

scholarly journals Myelin and axon pathology in multiple sclerosis assessed by myelin water and multi-shell diffusion imaging

Brain ◽  
2021 ◽  
Author(s):  
Reza Rahmanzadeh ◽  
Po-Jui Lu ◽  
Muhamed Barakovic ◽  
Matthias Weigel ◽  
Pietro Maggi ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
White Matter Lesions ◽  
Healthy Controls ◽  
Neurofilament Light Chain ◽  
Water Fraction ◽  
Neurite Density ◽  
Relapsing Remitting ◽  
Density Index ◽  
Myelin Water Fraction

Abstract Damage to the myelin sheath and the neuroaxonal unit is a cardinal feature of multiple sclerosis; however, a detailed characterization of the interaction between myelin and axon damage in vivo remains challenging. We applied myelin water and multi-shell diffusion imaging to quantify the relative damage to myelin and axons (i) among different lesion types; (ii) in normal-appearing tissue; and (iii) across multiple sclerosis clinical subtypes and healthy controls. We also assessed the relation of focal myelin/axon damage with disability and serum neurofilament light chain as a global biological measure of neuroaxonal damage. Ninety-one multiple sclerosis patients (62 relapsing-remitting, 29 progressive) and 72 healthy controls were enrolled in the study. Differences in myelin water fraction and neurite density index were substantial when lesions were compared to healthy controls and normal-appearing MS tissue: both white matter and cortical lesions exhibited a decreased myelin water fraction and neurite density index compared with healthy (P &lt; 0.0001) and peri-plaque white matter (P &lt; 0.0001). Periventricular lesions showed decreased myelin water fraction and neurite density index compared with lesions in the juxtacortical region (P &lt; 0.0001 and P &lt; 0.05). Similarly, lesions with paramagnetic rims showed decreased myelin water fraction and neurite density index relative to lesions without a rim (P &lt; 0.0001). Also, in 75% of white matter lesions, the reduction in neurite density index was higher than the reduction in the myelin water fraction. Besides, normal-appearing white and grey matter revealed diffuse reduction of myelin water fraction and neurite density index in multiple sclerosis compared to healthy controls (P &lt; 0.01). Further, a more extensive reduction in myelin water fraction and neurite density index in normal-appearing cortex was observed in progressive versus relapsing-remitting participants. Neurite density index in white matter lesions correlated with disability in patients with clinical deficits (P &lt; 0.01, beta=-10.00); and neurite density index and myelin water fraction in white matter lesions were associated to serum neurofilament light chain in the entire patients cohort (P &lt; 0.01, beta=-3.60 and P &lt; 0.01, beta=0.13, respectively). These findings suggest that (i) myelin and axon pathology in multiple sclerosis is extensive in both lesions and normal-appearing tissue; (ii) particular types of lesions exhibit more damage to myelin and axons than others; (iii) progressive patients differ from relapsing-remitting because of more extensive axon/myelin damage in the cortex; and (iv) myelin and axon pathology in lesions is related to disability in patients with clinical deficits and global measures of neuroaxonal damage.

In vivo gradients of thalamic damage in paediatric multiple sclerosis: a window into pathology

Brain ◽  
2020 ◽  
Author(s):  
Ermelinda De Meo ◽  
Loredana Storelli ◽  
Lucia Moiola ◽  
Angelo Ghezzi ◽  
Pierangelo Veggiotti ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Magnetic Resonance ◽  
Fractional Anisotropy ◽  
Mean Diffusivity ◽  
White Matter Lesions ◽  
Healthy Controls ◽  
Paediatric Multiple Sclerosis ◽  
Multiple Sclerosis Patients

Abstract The thalamus represents one of the first structures affected by neurodegenerative processes in multiple sclerosis. A greater thalamic volume reduction over time, on its CSF side, has been described in paediatric multiple sclerosis patients. However, its determinants and the underlying pathological changes, likely occurring before this phenomenon becomes measurable, have never been explored. Using a multiparametric magnetic resonance approach, we quantified, in vivo, the different processes that can involve the thalamus in terms of focal lesions, microstructural damage and atrophy in paediatric multiple sclerosis patients and their distribution according to the distance from CSF/thalamus interface and thalamus/white matter interface. In 70 paediatric multiple sclerosis patients and 26 age- and sex-matched healthy controls, we tested for differences in thalamic volume and quantitative MRI metrics—including fractional anisotropy, mean diffusivity and T1/T2-weighted ratio—in the whole thalamus and in thalamic white matter, globally and within concentric bands originating from CSF/thalamus interface. In paediatric multiple sclerosis patients, the relationship of thalamic abnormalities with cortical thickness and white matter lesions was also investigated. Compared to healthy controls, patients had significantly increased fractional anisotropy in whole thalamus (f2 = 0.145; P = 0.03), reduced fractional anisotropy (f2 = 0.219; P = 0.006) and increased mean diffusivity (f2 = 0.178; P = 0.009) in thalamic white matter and a trend towards a reduced thalamic volume (f2 = 0.027; P = 0.058). By segmenting the whole thalamus and thalamic white matter into concentric bands, in paediatric multiple sclerosis we detected significant fractional anisotropy abnormalities in bands nearest to CSF (f2 = 0.208; P = 0.002) and in those closest to white matter (f2 range = 0.183–0.369; P range = 0.010–0.046), while we found significant mean diffusivity (f2 range = 0.101–0.369; P range = 0.018–0.042) and T1/T2-weighted ratio (f2 = 0.773; P = 0.001) abnormalities in thalamic bands closest to CSF. The increase in fractional anisotropy and decrease in mean diffusivity detected at the CSF/thalamus interface correlated with cortical thickness reduction (r range = −0.27–0.34; P range = 0.004–0.028), whereas the increase in fractional anisotropy detected at the thalamus/white matter interface correlated with white matter lesion volumes (r range = 0.24–0.27; P range = 0.006–0.050). Globally, our results support the hypothesis of heterogeneous pathological processes, including retrograde degeneration from white matter lesions and CSF-mediated damage, leading to thalamic microstructural abnormalities, likely preceding macroscopic tissue loss. Assessing thalamic microstructural changes using a multiparametric magnetic resonance approach may represent a target to monitor the efficacy of neuroprotective strategies early in the disease course.

Focal multiple sclerosis lesions abound in ‘normal appearing white matter’

2011 ◽  
Vol 17 (11) ◽  
pp. 1313-1323 ◽  
Author(s):  
Niraj Mistry ◽  
Emma C Tallantyre ◽  
Jennifer E Dixon ◽  
Nicolas Galazis ◽  
Tim Jaspan ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
High Field ◽  
White Matter Lesions ◽  
7 Tesla ◽  
Ultra High Field ◽  
Rapid Acquisition ◽  
Normal Appearing White Matter ◽  
Mri Scans ◽  
Image Type

Background: The ‘normal appearing white matter’ (NAWM) in multiple sclerosis (MS) is known to be abnormal using quantitative magnetic resonance (MR) techniques. The aetiology of the changes in NAWM remains debatable. Objective: To investigate whether high-field and ultra high-field T1-weighted magnetization prepared rapid acquisition gradient echo (MPRAGE) MRI enables detection of MS white matter lesions in areas defined as NAWM using high-field T2-weighted fluid attenuation inversion recovery (FLAIR) MRI; that is, to ascertain whether undetected lesions are likely contributors to the burden of abnormality in similarly defined NAWM. Methods: Fourteen MS patients underwent MRI scans using 3T FLAIR and MPRAGE and 7 Tesla (7T) MPRAGE sequences. Independent observers identified lesions on 3T FLAIR and (7T and 3T) MPRAGE images. The detection of every individual lesion was then compared for each image type. Results: We identified a total of 812 white matter lesions on 3T FLAIR. Using 3T MPRAGE, 186 additional lesions were detected that were not detected using 3T FLAIR. Using 7T MPRAGE, 231 additional lesions were detected that were not detected using 3T FLAIR. Conclusions: MRI with 3T and 7T MPRAGE enables detection of MS lesions in areas defined as NAWM using 3T FLAIR. Focal MS lesions contribute to the abnormalities known to exist in the NAWM.

scholarly journals Neurite density is reduced in the presymptomatic phase of C9orf72 disease

2018 ◽  
Vol 90 (4) ◽  
pp. 387-394 ◽  
Author(s):  
Junhao Wen ◽  
Hui Zhang ◽  
Daniel C Alexander ◽  
Stanley Durrleman ◽  
Alexandre Routier ◽  
...  
Keyword(s):  
White Matter ◽  
Effect Size ◽  
Grey Matter ◽  
Free Water ◽  
Chromosome 9 ◽  
Grey Matter Volume ◽  
Water Fraction ◽  
White Matter Abnormalities ◽  
Neurite Density ◽  
Density Index

ObjectiveTo assess the added value of neurite orientation dispersion and density imaging (NODDI) compared with conventional diffusion tensor imaging (DTI) and anatomical MRI to detect changes in presymptomatic carriers of chromosome 9 open reading frame 72 (C9orf72) mutation.MethodsThe PREV-DEMALS (Predict to Prevent Frontotemporal Lobar Degeneration and Amyotrophic Lateral Sclerosis) study is a prospective, multicentre, observational study of first-degree relatives of individuals carrying the C9orf72 mutation. Sixty-seven participants (38 presymptomatic C9orf72 mutation carriers (C9+) and 29 non-carriers (C9−)) were included in the present cross-sectional study. Each participant underwent one single-shell, multishell diffusion MRI and three-dimensional T1-weighted MRI. Volumetric measures, DTI and NODDI metrics were calculated within regions of interest. Differences in white matter integrity, grey matter volume and free water fraction between C9+ and C9− individuals were assessed using linear mixed-effects models.ResultsCompared with C9−, C9+ demonstrated white matter abnormalities in 10 tracts with neurite density index and only 5 tracts with DTI metrics. Effect size was significantly higher for the neurite density index than for DTI metrics in two tracts. No tract had a significantly higher effect size for DTI than for NODDI. For grey matter cortical analysis, free water fraction was increased in 13 regions in C9+, whereas 11 regions displayed volumetric atrophy.ConclusionsNODDI provides higher sensitivity and greater tissue specificity compared with conventional DTI for identifying white matter abnormalities in the presymptomatic C9orf72 carriers. Our results encourage the use of neurite density as a biomarker of the preclinical phase.Trial registration numberNCT02590276.

scholarly journals Cortical axonal loss is associated with both gray matter demyelination and white matter tract pathology in progressive multiple sclerosis: Evidence from a combined MRI-histopathology study

2020 ◽  
pp. 135245852091897 ◽  
Author(s):  
Svenja Kiljan ◽  
Paolo Preziosa ◽  
Laura E Jonkman ◽  
Wilma DJ van de Berg ◽  
Jos Twisk ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
White Matter Lesions ◽  
Progressive Multiple Sclerosis ◽  
Axonal Loss ◽  
Normal Appearing White Matter ◽  
Axonal Density ◽  
Neuroaxonal Degeneration

Background: Neuroaxonal degeneration is one of the hallmarks of clinical deterioration in progressive multiple sclerosis (PMS). Objective: To elucidate the association between neuroaxonal degeneration and both local cortical and connected white matter (WM) tract pathology in PMS. Methods: Post-mortem in situ 3T magnetic resonance imaging (MRI) and cortical tissue blocks were collected from 16 PMS donors and 10 controls. Cortical neuroaxonal, myelin, and microglia densities were quantified histopathologically. From diffusion tensor MRI, fractional anisotropy, axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) were quantified in normal-appearing white matter (NAWM) and white matter lesions (WML) of WM tracts connected to dissected cortical regions. Between-group differences and within-group associations were investigated through linear mixed models. Results: The PMS donors displayed significant axonal loss in both demyelinated and normal-appearing (NA) cortices ( p < 0.001 and p = 0.02) compared with controls. In PMS, cortical axonal density was associated with WML MD and AD ( p = 0.003; p = 0.02, respectively), and NAWM MD and AD ( p = 0.04; p = 0.049, respectively). NAWM AD and WML AD explained 12.6% and 22.6%, respectively, of axonal density variance in NA cortex. Additional axonal loss in demyelinated cortex was associated with cortical demyelination severity ( p = 0.002), explaining 34.4% of axonal loss variance. Conclusion: Reduced integrity of connected WM tracts and cortical demyelination both contribute to cortical axonal loss in PMS.

scholarly journals Optimal indicator for histogram analysis of fractional anisotropy for normal-appearing white matter in multiple sclerosis

2021 ◽  
Vol 26 (4) ◽  
pp. 785-793
Author(s):  
Kimihiro Ogisu ◽  
Masaaki Niino ◽  
Yusei Miyazaki ◽  
Seiji Kikuchi
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Single Shot ◽  
Healthy Controls ◽  
Planar Imaging ◽  
Diffusion Weighted Images ◽  
Normal Appearing White Matter ◽  
Imaging Sequence ◽  
Scale Scores

Background: Normal-appearing white matter (NAWM) lesions are known to be present in multiple sclerosis (MS); however, it is not easy to distinguish these lesions from others in MRI. This study aimed to investigate the most useful value for estimating NAWM damage using fractional anisotropy (FA) histograms analysis. Methods: Data from patients with relapsing-remitting MS and healthy controls were analyzed using a 1.5T MRI system with SENSE-Head-8 coil. FA maps with diffusion- weighted images were acquired using a single-shot echo-planar imaging sequence. The median, standard deviation (SD), kurtosis, and skewness of white matter (WM) of each subject were compared between MS and healthy controls using an in-house application. Results: FA decrease in 8 patients with MS was observed upon comparison with 12 controls and leaned toward the left side. While the SDs of the healthy controls were not significantly different from those of patients with MS, patients with MS expressed significantly lower median values, and higher kurtosis and skewness compared to healthy controls. A trend for inverse associations existed between median and expanded disability status scale scores. Conclusion: Our data suggests that median FA values can allow for distinguishing between patients with MS and healthy controls with high accuracy.

scholarly journals Investigating Microstructural Changes in White Matter in Multiple Sclerosis: A Systematic Review and Meta-Analysis of Neurite Orientation Dispersion and Density Imaging

2021 ◽  
Vol 11 (9) ◽  
pp. 1151
Author(s):  
Abdulmajeed Alotaibi ◽  
Anna Podlasek ◽  
Amjad AlTokhis ◽  
Ali Aldhebaib ◽  
Rob A. Dineen ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Systematic Review ◽  
White Matter ◽  
Diffusion Tensor ◽  
Meta Analysis ◽  
Random Effect ◽  
Microstructural Changes ◽  
Neurite Density ◽  
Normal Appearing White Matter ◽  
Significant Difference

Multiple sclerosis (MS) is characterised by widespread damage of the central nervous system that includes alterations in normal-appearing white matter (NAWM) and demyelinating white matter (WM) lesions. Neurite orientation dispersion and density imaging (NODDI) has been proposed to provide a precise characterisation of WM microstructures. NODDI maps can be calculated for the Neurite Density Index (NDI) and Orientation Dispersion Index (ODI), which estimate orientation dispersion and neurite density. Although NODDI has not been widely applied in MS, this technique is promising in investigating the complexity of MS pathology, as it is more specific than diffusion tensor imaging (DTI) in capturing microstructural alterations. We conducted a meta-analysis of studies using NODDI metrics to assess brain microstructural changes and neuroaxonal pathology in WM lesions and NAWM in patients with MS. Three reviewers conducted a literature search of four electronic databases. We performed a random-effect meta-analysis and the extent of between-study heterogeneity was assessed with the I2 statistic. Funnel plots and Egger’s tests were used to assess publication bias. We identified seven studies analysing 374 participants (202 MS and 172 controls). The NDI in WM lesions and NAWM were significantly reduced compared to healthy WM and the standardised mean difference of each was −3.08 (95%CI −4.22 to (−1.95), p ≤ 0.00001, I2 = 88%) and −0.70 (95%CI −0.99 to (−0.40), p ≤ 0.00001, I2 = 35%), respectively. There was no statistically significant difference of the ODI in MS WM lesions and NAWM compared to healthy controls. This systematic review and meta-analysis confirmed that the NDI is significantly reduced in MS lesions and NAWM than in WM from healthy participants, corresponding to reduced intracellular signal fraction, which may reflect underlying damage or loss of neurites.

scholarly journals Disentangling white-matter damage from physiological fibre orientation dispersion in multiple sclerosis

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Kasper Winther Andersen ◽  
Samo Lasič ◽  
Henrik Lundell ◽  
Markus Nilsson ◽  
Daniel Topgaard ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Diffusion Mri ◽  
Fibre Orientation ◽  
Cerebral White Matter ◽  
Healthy Controls ◽  
Lesion Load ◽  
Normal Appearing White Matter ◽  
Relapsing Remitting

Abstract Multiple sclerosis leads to diffuse damage of the central nervous system, affecting also the normal-appearing white matter. Demyelination and axonal degeneration reduce regional fractional anisotropy in normal-appearing white matter, which can be routinely mapped with diffusion tensor imaging. However, the standard fractional anisotropy metric is also sensitive to physiological variations in orientation dispersion of white matter fibres. This complicates the detection of disease-related damage in large parts of cerebral white matter where microstructure physiologically displays a high degree of fibre dispersion. To resolve this ambiguity, we employed a novel tensor-valued encoding method for diffusion MRI, which yields a microscopic fractional anisotropy metric that is unaffected by regional variations in orientation dispersion. In 26 patients with relapsing-remitting multiple sclerosis, 14 patients with primary-progressive multiple sclerosis and 27 age-matched healthy controls, we compared standard fractional anisotropy mapping with the novel microscopic fractional anisotropy mapping method, focusing on normal-appearing white matter. Mean microscopic fractional anisotropy and standard fractional anisotropy of normal-appearing white matter were significantly reduced in both patient groups relative to healthy controls, but microscopic fractional anisotropy yielded a better reflection of disease-related white-matter alterations. The reduction in mean microscopic fractional anisotropy showed a significant positive linear relationship with physical disability, as reflected by the expanded disability status scale. Mean reduction of microscopic fractional anisotropy in normal-appearing white matter also scaled positively with individual cognitive dysfunction, as measured with the symbol digit modality test. Mean microscopic fractional anisotropy reduction in normal-appearing white matter also showed a positive relationship with total white-matter lesion load as well as lesion load in specific tract systems. None of these relationships between normal-appearing white-matter microstructure and clinical, cognitive or structural measures emerged when using mean fractional anisotropy. Together, the results provide converging evidence that microscopic fractional anisotropy mapping substantially advances the assessment of cerebral white matter in multiple sclerosis by disentangling microstructure damage from variations in physiological fibre orientation dispersion at the stage of data acquisition. Since tensor-valued encoding can be implemented in routine diffusion MRI, microscopic fractional anisotropy mapping bears considerable potential for the future assessment of disease progression in normal-appearing white matter in both relapsing-remitting and progressive forms of multiple sclerosis as well as other white-matter-related brain diseases.

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