Expansion of chronic MS lesions is associated with an increase of radial diffusivity in periplaque white matter

2021 ◽  
pp. 135245852110334
Author(s):  
Samuel Klistorner ◽  
Michael H Barnett ◽  
Con Yiannikas ◽  
Joshua Barton ◽  
John Parratt ◽  
...  

Background: Expansion of chronic multiple sclerosis (MS) lesion is associated with slow-burning inflammation at lesion rim. However, the underlying mechanisms leading to expansion are not fully understood. Objective: To investigate the relationship between diffusivity markers of demyelination and axonal loss in perilesional white matter and lesion expansion in relapsing-remitting MS (RRMS). Methods: T1, FLAIR and diffusion tensor images were acquired from 30 patients. Novel single-streamline technique was used to estimate diffusivity in lesions, perilesional white matter and normal-appearing white matter (NAWM). Results: Significant association was found between baseline periplaque radial diffusivity (RD) and subsequent lesion expansion. Conversely, periplaque axial diffusivity (AD) did not correlate with lesion growth. Baseline RD (but not AD) in periplaque white matter of expanding lesions was significantly higher compared with non-expanding lesions. Correlation between increase of both RD and AD in the periplaque area during follow-up period and lesion expansion was noticeably stronger for RD. Increase of RD in periplaque area was also much higher compared to AD. There was significant increase of AD and RD in the periplaque area of expanding, but not in non-expanding, lesions. Conclusion: Periplaque demyelination is likely to be an initial step in a process of lesion expansion and, as such, potentially represents a suitable target for remyelinating therapies.

2018 ◽  
Vol 32 (1) ◽  
pp. 10-16
Author(s):  
Alexander Rau ◽  
Elias Kellner ◽  
Niels A Foit ◽  
Niklas Lützen ◽  
Dieter H Heiland ◽  
...  

The aim of this study was to evaluate whether ganglioglioma (GGL), dysembryoplastic neuroepithelial tumour (DNET) and FCD (focal cortical dysplasia) are distinguishable through diffusion tensor imaging. Additionally, it was investigated whether the diffusion measures differed in the perilesional (pNAWM) and in the contralateral normal appearing white matter (cNAWM). Six GGLs, eight DNETs and seven FCDs were included in this study. Quantitative diffusion measures, that is, axial, radial and mean diffusivity and fractional anisotropy, were determined in the lesion identified on isotropic T2 or FLAIR-weighted images and in pNAWM and cNAWM, respectively. DNET differed from FCD in mean diffusivity, and GGL from FCD in radial diffusivity. Both types of glioneuronal tumours were different from pNAWM in fractional anisotropy and radial diffusivity. For identifying the tumour edges, threshold values for tumour-free tissue were investigated with receiver operating characteristic analyses: tumour could be separated from pNAWM at a threshold ≤ 0.32 (fractional anisotropy) or ≥ 0.56 (radial diffusivity) *10–3 mm2/s (area under the curve 0.995 and 0.990 respectively). While diffusion parameters of FCDs differed from cNAWM (radial diffusivity (*10–3 mm/s2): 0.74 ± 0.19 vs. 0.43 ± 0.05; corrected p-value < 0.001), the pNAWM could not be differentiated from the FCD.


2004 ◽  
Vol 10 (2) ◽  
pp. 188-196 ◽  
Author(s):  
Emmanuelle Cassol ◽  
Jean-Philippe Ranjeva ◽  
Danielle Ibarrola ◽  
Claude Mékies ◽  
Claude Manelfe ◽  
...  

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.


2017 ◽  
Vol 24 (4) ◽  
pp. 491-500 ◽  
Author(s):  
Antoine M Klauser ◽  
Oliver T Wiebenga ◽  
Anand JC Eijlers ◽  
Menno M Schoonheim ◽  
Bernard MJ Uitdehaag ◽  
...  

Background: Multiple sclerosis is characterized by white matter lesions, which are visualized with conventional T2-weighted magnetic resonance imaging (MRI). Little is known about local metabolic processes preceding the appearance and during the pathological development of new lesions. Objective: To identify metabolite changes preceding white matter (WM) lesions and pathological severity of lesions over time. Methods: A total of 59 relapsing-remitting multiple sclerosis (MS) patients were scanned four times, with 6-month intervals. Imaging included short-TE magnetic resonance spectroscopic imaging (MRSI) and diffusion tensor imaging (DTI). Results: A total of 16 new lesions appeared within the MRSI slab in 12 patients. Glutamate increased (+1.0 mM (+19%), p = 0.039) 12 and 6 months before new lesions appeared. In these areas, the increase in creatine and choline 6 months before until lesion appearance was negatively correlated with radial diffusivity (ρ = −0.73, p = 0.002 and ρ = −0.72, p = 0.002). Increase in creatine also correlated with the increase of axial diffusivity in the same period (ρ = −0.53, p = 0.034). When splitting the lesions into “mild” and “severe” based on radial diffusivity, only mild lesions showed an increase in creatine and choline during lesion formation ( p = 0.039 and p = 0.008, respectively). Conclusion: Increased glutamate heralded the appearance of new T2-visible WM lesions. In pathologically “mild” lesions, an increase in creatine and choline was found during lesion formation.


2019 ◽  
pp. 174749301989570
Author(s):  
Mark R Etherton ◽  
Ona Wu ◽  
Anne-Katrin Giese ◽  
Natalia S Rost

Background White matter hyperintensity of presumed vascular origin is a risk factor for poor stroke outcomes. In patients with acute ischemic stroke, however, the in vivo mechanisms of white matter microstructural injury are less clear. Aims To characterize the directional diffusivity components in normal-appearing white matter and white matter hyperintensity in acute ischemic stroke patients. Methods A retrospective analysis was performed on a cohort of patients with acute ischemic stroke and brain magnetic resonance imaging with diffusion tensor imaging sequences acquired within 48 h of admission. White matter hyperintensity volume was measured in a semi-automated manner. Median fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity values were calculated within normal-appearing white matter and white matter hyperintensity in the hemisphere contralateral to the acute infarct. Linear regression analysis was performed to evaluate predictors of white matter hyperintensity volume and normal-appearing white matter diffusivity metrics. Results In 319 patients, mean age was 64.9 ± 15.9 years. White matter hyperintensity volume was 6.33 cm3 (interquartile range 3.0–12.6 cm3). Axial and radial diffusivity were significantly increased in white matter hyperintensity compared to normal-appearing white matter. In multivariable linear regression, age (β = 0.20, P = 0.003) and normal-appearing white matter axial diffusivity (β = 37.9, P < 0.001) were independently associated with white matter hyperintensity volume. Subsequent analysis demonstrated that increasing age (β = 0.004, P < 0.001) and admission diastolic blood pressure (β = 0.001, P = 0.02) were independent predictors of normal-appearing white matter axial diffusivity in multivariable linear regression. Conclusions Normal-appearing white matter axial diffusivity increases with age and is an independent predictor of white matter hyperintensity volume in acute ischemic stroke.


2017 ◽  
Vol 25 (2) ◽  
pp. 204-216 ◽  
Author(s):  
Gianna C Riccitelli ◽  
Elisabetta Pagani ◽  
Mariaemma Rodegher ◽  
Bruno Colombo ◽  
Paolo Preziosa ◽  
...  

Objectives: To map the regional patterns of white matter (WM) microstructural abnormalities and gray matter (GM) atrophy exclusively associated with reduced performance in the Symbol Digit Modalities Test (SDMT) and Paced Auditory Serial Addition Test (PASAT) in relapsing-remitting (RR) multiple sclerosis (MS) patients. Methods: In all, 177 RRMS patients and 80 healthy controls (HC) were studied. WM microstructural abnormalities were investigated on diffusion tensor images using tract-based spatial statistics analysis, and regional GM atrophy was estimated on three-dimensional (3D) T1-weighted images using voxel-based morphometry. Results: Compared to HC, RRMS patients showed the expected pattern of cortical–subcortical GM atrophy and WM microstructural abnormalities. In patients, diffusivity abnormalities of supratentorial WM tracts correlated with both SDMT and PASAT scores. Lower SDMT performance was also associated with WM damage in several infratentorial WM tracts. Lower SDMT scores correlated with atrophy of the right anterior cingulate cortex, left postcentral gyrus, and right middle temporal gyrus, whereas lower PASAT scores correlated with atrophy of the deep GM nuclei, bilaterally, and several fronto-temporo-occipital regions. Conclusion: In RRMS patients, regional damage of different neural systems helps explaining reduced performance in SDMT and PASAT. WM microstructural damage typified reduced SDMT performance, whereas atrophy of several GM regions distinguished reduced PASAT performance.


2017 ◽  
Vol 30 (5) ◽  
pp. 454-460
Author(s):  
Dana M Middleton ◽  
Jonathan Y Li ◽  
Steven D Chen ◽  
Leonard E White ◽  
Patricia I Dickson ◽  
...  

Purpose We compared fractional anisotropy and radial diffusivity measurements between pediatric canines affected with mucopolysaccharidosis I and pediatric control canines. We hypothesized that lower fractional anisotropy and higher radial diffusivity values, consistent with dysmyelination, would be present in the mucopolysaccharidosis I cohort. Methods Six canine brains, three affected with mucopolysaccharidosis I and three unaffected, were euthanized at 7 weeks and imaged using a 7T small-animal magnetic resonance imaging system. Average fractional anisotropy and radial diffusivity values were calculated for four white-matter regions based on 100 regions of interest per region per specimen. A 95% confidence interval was calculated for each mean value. Results No difference was seen in fractional anisotropy or radial diffusivity values between mucopolysaccharidosis affected and unaffected brains in any region. In particular, the 95% confidence intervals for mucopolysaccharidosis affected and unaffected canines frequently overlapped for both fractional anisotropy and radial diffusivity measurements. In addition, in some brain regions a large range of fractional anisotropy and radial diffusivity values were seen within the same cohort. Conclusion The fractional anisotropy and radial diffusivity values of white matter did not differ between pediatric mucopolysaccharidosis affected canines and pediatric control canines. Possible explanations include: (a) a lack of white matter tissue differences between mucopolysaccharidosis affected and unaffected brains at early disease stages; (b) diffusion tensor imaging does not detect any existing differences; (c) inflammatory processes such as astrogliosis produce changes that offset the decreased fractional anisotropy values and increased radial diffusivity values that are expected in dysmyelination; and (d) our sample size was insufficient to detect differences. Further studies correlating diffusion tensor imaging findings to histology are warranted.


NeuroImage ◽  
2011 ◽  
Vol 58 (2) ◽  
pp. 458-468 ◽  
Author(s):  
Pierre-Louis Bazin ◽  
Chuyang Ye ◽  
John A. Bogovic ◽  
Navid Shiee ◽  
Daniel S. Reich ◽  
...  

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