Normal-appearing White Matter in Patients with Phenylketonuria: Water Content, Myelin Water Fraction, and Metabolite Concentrations

Radiology ◽  
2007 ◽  
Vol 242 (1) ◽  
pp. 236-243 ◽  
Author(s):  
Sandra M. Sirrs ◽  
Cornelia Laule ◽  
Burkhard Mädler ◽  
Elana E. Brief ◽  
Sumia A. Tahir ◽  
...  
Keyword(s):  
White Matter ◽  
Water Content ◽  
Water Fraction ◽  
Normal Appearing White Matter ◽  
Metabolite Concentrations ◽  
Myelin Water Fraction

Pathological basis of diffusely abnormal white matter: insights from magnetic resonance imaging and histology

2010 ◽  
Vol 17 (2) ◽  
pp. 144-150 ◽  
Author(s):  
Cornelia Laule ◽  
Irene M Vavasour ◽  
Esther Leung ◽  
David KB Li ◽  
Piotr Kozlowski ◽  
...  
Keyword(s):  
White Matter ◽  
Magnetization Transfer ◽  
Selective Reduction ◽  
Myelin Proteins ◽  
Water Fraction ◽  
Normal Appearing White Matter ◽  
Three Samples ◽  
Disability Status ◽  
Myelin Water Fraction

Background: The pathological basis of diffusely abnormal white matter (DAWM) in multiple sclerosis (MS) has not been elucidated in detail, but may be an important element in disability and clinical progression. Methods: Fifty-three subjects with MS were examined with T1, multi-echo T2 and magnetization transfer (MT). Twenty-three samples of formalin-fixed MS brain tissue were examined with multi-echo T2 and subsequently stained for myelin phospholipids using luxol fast blue, for axons using Bielschowsky, immunohistochemically for the myelin proteins myelin basic protein (MBP) and 2′,3′-cyclic nucleotide 3′ phosphohydrolase (CNP) and for astrocytes using glial fibrillary acidic protein (GFAP). Regions of interest in DAWM were compared with normal appearing white matter. Results: Fourteen of 53 subjects with MS in the in vivo study showed the presence of DAWM. Subjects with DAWM were found to have a significantly lower Expanded Disability Status Scale (EDSS) and shorter disease duration (DD) when compared with subjects without DAWM (EDSS: 1.5 versus 3.0, p = 0.031; DD: 5.4 versus 10.3 years, p = 0.045). DAWM in vivo had reduced myelin water and MT ratio, and increased T2 and water content. Histological analysis suggests DAWM, which shows a reduction of the myelin water fraction, is characterized by selective reduction of myelin phospholipids, but with a relative preservation of myelin proteins and axons. Conclusions: These findings suggest that the primary abnormality in DAWM is a reduction or perturbation of myelin phospholipids that correlates with a reduction of the myelin water fraction.

Myelin Water Fraction Imaging Reveals Hemispheric Asymmetries in Human White Matter That Are Associated with Genetic Variation in PLP1

2018 ◽  
Vol 56 (6) ◽  
pp. 3999-4012 ◽  
Author(s):  
Sebastian Ocklenburg ◽  
Catrona Anderson ◽  
Wanda M. Gerding ◽  
Christoph Fraenz ◽  
Caroline Schlüter ◽  
...  
Keyword(s):  
Genetic Variation ◽  
White Matter ◽  
Hemispheric Asymmetries ◽  
Water Fraction ◽  
Myelin Water Fraction

scholarly journals Age-Related Measurements of the Myelin Water Fraction derived from 3D multi-echo GRASE reflect Myelin Content of the Cerebral White Matter

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Tobias D. Faizy ◽  
Dushyant Kumar ◽  
Gabriel Broocks ◽  
Christian Thaler ◽  
Fabian Flottmann ◽  
...  
Keyword(s):  
White Matter ◽  
Cerebral White Matter ◽  
Water Fraction ◽  
Age Related ◽  
Myelin Water Fraction

White-matter relaxation time and myelin water fraction differences in young adults with autism

2014 ◽  
Vol 45 (4) ◽  
pp. 795-805 ◽  
Author(s):  
S. C. L. Deoni ◽  
J. R. Zinkstok ◽  
E. Daly ◽  
C. Ecker ◽  
S. C. R. Williams ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Brain Connectivity ◽  
Critical Role ◽  
Relaxation Times ◽  
Imaging Study ◽  
Autism Diagnostic Observation Schedule ◽  
Cross Sectional ◽  
Water Fraction ◽  
Myelin Water Fraction

BackgroundIncreasing evidence suggests that autism is associated with abnormal white-matter (WM) anatomy and impaired brain ‘connectivity’. While myelin plays a critical role in synchronized brain communication, its aetiological role in autistic symptoms has only been indirectly addressed by WM volumetric, relaxometry and diffusion tensor imaging studies. A potentially more specific measure of myelin content, termed myelin water fraction (MWF), could provide improved sensitivity to myelin alteration in autism.MethodWe performed a cross-sectional imaging study that compared 14 individuals with autism and 14 age- and IQ-matched controls. T1 relaxation times (T1), T2 relaxation times (T2) and MWF values were compared between autistic subjects, diagnosed using the Autism Diagnostic Interview – Revised (ADI-R), with current symptoms assessed using the Autism Diagnostic Observation Schedule (ADOS) and typical healthy controls. Correlations between T1, T2 and MWF values with clinical measures [ADI-R, ADOS, and the Autism Quotient (AQ)] were also assessed.ResultsIndividuals with autism showed widespread WM T1 and MWF differences compared to typical controls. Within autistic individuals, worse current social interaction skill as measured by the ADOS was related to reduced MWF although not T1. No significant differences or correlations with symptoms were observed with respect to T2.ConclusionsAutistic individuals have significantly lower global MWF and higher T1, suggesting widespread alteration in tissue microstructure and biochemistry. Areas of difference, including thalamic projections, cerebellum and cingulum, have previously been implicated in the disorder; however, this is the first study to specifically indicate myelin alteration in these regions.

scholarly journals Motor Skill Acquisition Promotes Human Brain Myelin Plasticity

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Bimal Lakhani ◽  
Michael R. Borich ◽  
Jacob N. Jackson ◽  
Katie P. Wadden ◽  
Sue Peters ◽  
...  
Keyword(s):  
Young Adults ◽  
White Matter ◽  
Skill Acquisition ◽  
Motor Skill ◽  
Structural Changes ◽  
Skill Training ◽  
Quantitative Measure ◽  
Water Fraction ◽  
Motor Skill Acquisition ◽  
Myelin Water Fraction

Experience-dependent structural changes are widely evident in gray matter. Using diffusion weighted imaging (DWI), the neuroplastic effect of motor training on white matter in the brain has been demonstrated. However, in humans it is not known whether specific features of white matter relate to motor skill acquisition or if these structural changes are associated to functional network connectivity. Myelin can be objectively quantifiedin vivoand used to index specific experience-dependent change. In the current study, seventeen healthy young adults completed ten sessions of visuomotor skill training (10,000 total movements) using the right arm. Multicomponent relaxation imaging was performed before and after training. Significant increases in myelin water fraction, a quantitative measure of myelin, were observed in task dependent brain regions (left intraparietal sulcus [IPS] and left parieto-occipital sulcus). In addition, the rate of motor skill acquisition and overall change in myelin water fraction in the left IPS were negatively related, suggesting that a slower rate of learning resulted in greater neuroplastic change. This study provides the first evidence for experience-dependent changes in myelin that are associated with changes in skilled movements in healthy young adults.

scholarly journals Myelination of major white matter tracts continues beyond childhood—combining tractography and myelin water imaging

2019 ◽  
Author(s):  
Tobias W. Meissner ◽  
Erhan Genç ◽  
Burkhard Mädler ◽  
Sarah Weigelt
Keyword(s):  
White Matter ◽  
Middle Childhood ◽  
Diffusion Tensor ◽  
Late Childhood ◽  
White Matter Tracts ◽  
Water Fraction ◽  
White Matter Maturation ◽  
Myelin Water Fraction ◽  
Diffusion Tensor Imaging Dti

AbstractAxonal myelination is a key white matter maturation process as it increases conduction velocity, synchrony, and reliability. While diffusion tensor imaging (DTI) is sensitive to myelination, it is also sensitive to unrelated microstructural properties, thus hindering straightforward interpretations. Myelin water imaging (MWI) provides a more reliable and direct in vivo measure of myelination. Although early histological studies show protracted myelination from childhood to adulthood, reliable tract-specific in vivo evidence from MWI is still lacking. Here, we combine MWI and DTI tractography to investigate myelination in middle childhood, late childhood, and adulthood in 18 major white matter tracts. In the vast majority of major white matter tracts, myelin water fraction continued to increase beyond late childhood. Our study provides first in vivo evidence for protracted myelination beyond late childhood.

scholarly journals Myelin water fraction decrease in mild traumatic brain injury

2020 ◽  
Author(s):  
Bretta Russell-Schulz ◽  
Irene Vavasour ◽  
Jing Zhang ◽  
Alex L. MacKay ◽  
Victoria Purcell ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
White Matter ◽  
Cognitive Status ◽  
Healthy Controls ◽  
Cognitive Measures ◽  
Mild Tbi ◽  
Water Fraction ◽  
Inferior Longitudinal Fasciculus ◽  
Myelin Water Fraction

AbstractThe increased incidence of reported traumatic brain injury (TBI) and its potentially serious long-term consequences have enormous clinical and societal impacts. The diffuse and continually evolving secondary changes after TBI make it challenging to evaluate the changes in brain-behaviour relationships. In this study we used myelin water imaging to evaluate changes in myelin water fraction (MWF) in individuals with chronic brain injury and evaluated their cognitive status using the NIH Toolbox Cognitive Battery. Twenty-two adults with mild or severe brain injury and twelve age, gender and education matched healthy controls took part in this study. We found a significant decrease in global white matter MWF in individuals with mild TBI compared to the healthy controls. Significantly lower MWF was evident in most white matter ROIs examined including the corpus callosum (separated into genu, body and splenium), minor forceps, right anterior thalamic radiation, left inferior longitudinal fasciculus; and right and left superior longitudinal fasciculus and corticospinal tract. No significant correlations were found between MWF in mild TBI and the cognitive measures. These results show for the first time the loss of myelin in chronic mild TBI.

scholarly journals A Comparison of Magnetic Resonance Imaging Methods to Assess Multiple Sclerosis Lesions: Implications for Patient Characterization and Clinical Trial Design

Diagnostics ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 77
Author(s):  
Ewart Mark Haacke ◽  
Evanthia Bernitsas ◽  
Karthik Subramanian ◽  
David Utriainen ◽  
Vinay Kumar Palutla ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Inversion Recovery ◽  
Resonance Imaging ◽  
Imaging Protocol ◽  
Imaging Methods ◽  
Water Fraction ◽  
Demyelinating Lesions ◽  
Myelin Water Fraction

Magnetic resonance imaging (MRI) is a sensitive imaging modality for identifying inflammatory and/or demyelinating lesions, which is critical for a clinical diagnosis of MS and evaluating drug responses. There are many unique means of probing brain tissue status, including conventional T1 and T2 weighted imaging (T1WI, T2WI), T2 fluid attenuated inversion recovery (FLAIR), magnetization transfer, myelin water fraction, diffusion tensor imaging (DTI), phase-sensitive inversion recovery and susceptibility weighted imaging (SWI), but no study has combined all of these modalities into a single well-controlled investigation. The goals of this study were to: compare different MRI measures for lesion visualization and quantification; evaluate the repeatability of various imaging methods in healthy controls; compare quantitative susceptibility mapping (QSM) with myelin water fraction; measure short-term longitudinal changes in the white matter of MS patients and map out the tissue properties of the white matter hyperintensities using STAGE (strategically acquired gradient echo imaging). Additionally, the outcomes of this study were anticipated to aid in the choice of an efficient imaging protocol reducing redundancy of information and alleviating patient burden. Of all the sequences used, T2 FLAIR and T2WI showed the most lesions. To differentiate the putative demyelinating lesions from inflammatory lesions, the fusion of SWI and T2 FLAIR was used. Our study suggests that a practical and efficient imaging protocol combining T2 FLAIR, T1WI and STAGE (with SWI and QSM) can be used to rapidly image MS patients to both find lesions and study the demyelinating and inflammatory characteristics of the lesions.

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