Post-mortem 7 Tesla MRI detection of white matter hyperintensities: A multidisciplinary voxel-wise comparison of imaging and histological correlates

In Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL), by contrast to sporadic cerebral small vessel disease related to age and hypertension, white matter hyperintensities (WMH) are frequently observed in the white matter of anterior temporal poles, external capsules, and superior frontal regions. Whether these WMH (specific WMH) differ from those observed in other white matter areas (nonspecific WMH) remains unknown. Twenty patients were scanned to compare specific and nonspecific WMH using high-resolution images and analyses of relaxation times (T1R: longitudinal relaxation time and T2*R: effective transversal relaxation time). Specific WMH were characterized by significantly longer T1R and T2*R (T1R: 2309 ± 120 ms versus 2145 ± 138 ms; T2*R: 40 ± 5 ms versus 35 ± 5 ms, p < 0.001). These results were not explained by the presence of dilated perivascular spaces found in the close vicinity of specific WMH. They were not either explained by the normal regional variability of T1R and T2*R in the white matter nor by systematic imaging artifacts as shown by the study of 17 age- and sex-matched healthy controls. Our results suggest large differences in water content between specific and nonspecific WMH in CADASIL, supporting that mechanisms underlying WMH may differ according to their location.

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Regional Lipid Expression Abnormalities Identified Using MALDI IMS Correspond to MRI-Defined White Matter Hyperintensities within Post-mortem Human Brain Tissues

Analytical Chemistry ◽

10.1021/acs.analchem.0c05017 ◽

2021 ◽

Vol 93 (4) ◽

pp. 2652-2659

Author(s):

William Pinsky ◽

Aaron Harris ◽

Austyn D. Roseborough ◽

Wenxuan Wang ◽

Ali R. Khan ◽

...

Keyword(s):

White Matter ◽

Human Brain ◽

White Matter Hyperintensities ◽

Post Mortem ◽

Maldi Ims ◽

Brain Tissues

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Case Report: An MRI Traumatic Brain Injury Longitudinal Case Study at 7 Tesla: Pre- and Post-injury Structural Network and Volumetric Reorganization and Recovery

Frontiers in Neurology ◽

10.3389/fneur.2021.631330 ◽

2021 ◽

Vol 12 ◽

Author(s):

Stephanie S. G. Brown ◽

Kristen Dams-O'Connor ◽

Eric Watson ◽

Priti Balchandani ◽

Rebecca E. Feldman

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

White Matter ◽

7 Tesla ◽

Cerebral White Matter ◽

Post Injury ◽

Whole Brain ◽

7 Tesla Mri ◽

Connection Density

Importance: A significant limitation of many neuroimaging studies examining mild traumatic brain injury (mTBI) is the unavailability of pre-injury data.Objective: We therefore aimed to utilize pre-injury ultra-high field brain MRI and compare a collection of neuroimaging metrics pre- and post-injury to determine mTBI related changes and evaluate the enhanced sensitivity of high-resolution MRI.Design: In the present case study, we leveraged multi-modal 7 Tesla MRI data acquired at two timepoints prior to mTBI (23 and 12 months prior to injury), and at two timepoints post-injury (2 weeks and 8 months after injury) to examine how a right parietal bone impact affects gross brain structure, subcortical volumetrics, microstructural order, and connectivity.Setting: This research was carried out as a case investigation at a single primary care site.Participants: The case participant was a 38-year-old female selected for inclusion based on a mTBI where a right parietal impact was sustained.Main outcomes: The main outcome measurements of this investigation were high spatial resolution structural brain metrics including volumetric assessment and connection density of the white matter connectome.Results: At the first scan timepoint post-injury, the cortical gray matter and cerebral white matter in both hemispheres appeared to be volumetrically reduced compared to the pre-injury and subsequent post-injury scans. Connectomes produced from whole-brain diffusion-weighted probabilistic tractography showed a widespread decrease in connectivity after trauma when comparing mean post-injury and mean pre-injury connection densities. Findings of reduced fractional anisotropy in the cerebral white matter of both hemispheres at post-injury time point 1 supports reduced connection density at a microstructural level. Trauma-related alterations to whole-brain connection density were markedly reduced at the final scan timepoint, consistent with symptom resolution.Conclusions and Relevance: This case study investigates the structural effects of traumatic brain injury for the first time using pre-injury and post-injury 7 Tesla MRI longitudinal data. We report findings of initial volumetric changes, decreased structural connectivity and reduced microstructural order that appear to return to baseline 8 months post-injury, demonstrating in-depth metrics of physiological recovery. Default mode, salience, occipital, and executive function network alterations reflect patient-reported hypersomnolence, reduced cognitive processing speed and dizziness.

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Quantitative Assessment of Secondary White Matter Injury in the Visual Pathway by Pituitary Adenomas: A Multimodal Study at 7 Tesla MRI

10.1055/s-0039-1679447 ◽

2019 ◽

Author(s):

John Rutland ◽

Francesco Padormo ◽

Cindi Yim ◽

Amy Yao ◽

Annie Arrighi-Allisan ◽

...

Keyword(s):

White Matter ◽

Pituitary Adenomas ◽

Quantitative Assessment ◽

Visual Pathway ◽

White Matter Injury ◽

7 Tesla ◽

7 Tesla Mri

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7 tesla MRI of microbleeds and white matter lesions as seen in vascular dementia

Journal of Magnetic Resonance Imaging ◽

10.1002/jmri.22513 ◽

2011 ◽

Vol 33 (4) ◽

pp. 782-791 ◽

Cited By ~ 52

Author(s):

Jens M. Theysohn ◽

Oliver Kraff ◽

Stefan Maderwald ◽

Markus Barth ◽

Susanne C. Ladd ◽

...

Keyword(s):

White Matter ◽

Vascular Dementia ◽

White Matter Lesions ◽

7 Tesla ◽

7 Tesla Mri

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IC-P1-026: Precise nature of the white matter hyperintensities: A biotechnological platform combining post mortem MRI in situ with comprehensive neuropathology

Alzheimer s & Dementia ◽

10.1016/j.jalz.2008.05.037 ◽

2008 ◽

Vol 4 ◽

pp. T19-T19

Author(s):

Lea T. Grinberg ◽

Edson Amaro ◽

Stefan Teipel ◽

Alexandre V. Silva ◽

Silmara P. Pacheco ◽

...

Keyword(s):

White Matter ◽

White Matter Hyperintensities ◽

Post Mortem ◽

Precise Nature

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Heterogeneity of White Matter Hyperintensities in Alzheimer's Disease: Post-Mortem Quantitative MRI and Neuropathology

The Neuroradiology Journal ◽

10.1177/19714009090220s110 ◽

2009 ◽

Vol 22 (1_suppl) ◽

pp. 51-63

Author(s):

A. A. Gouw ◽

A. Seewann ◽

H. Vrenken ◽

W. M. van der Flier ◽

J. M. Rozemuller ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

White Matter ◽

Microglial Activation ◽

White Matter Hyperintensities ◽

Quantitative Mri ◽

Post Mortem ◽

Patient Groups ◽

The Difference ◽

Axonal Density

White matter hyperintensities (WMH) are frequently seen on T2-weighted MRI scans of elderly subjects with and without Alzheimer's disease. WMH are only weakly and inconsistently associated with cognitive decline, which may be explained by heterogeneity of the underlying neuropathological substrates. The use of quantitative MRI could increase specificity for these neuropathological changes. We assessed whether post-mortem quantitative MRI is able to reflect differences in neuropathological correlates of WMH in tissue samples obtained post-mortem from Alzheimer's disease patients and from non-demented elderly. Thirty-three formalin-fixed, coronal brain slices from II Alzheimer's disease patients (mean age: 83 ± 10 years, eight females) and 15 slices from seven non-demented controls (mean age: 78 ± 10 years, four females) with WMH were scanned at 1.5 T using qualitative (fluid-attenuated inversion recovery, FLAIR) and quantitative MRI [diffusion tensor imaging (DTI) including estimation of apparent diffusion coefficient (ADC) and fractional anisotropy (FA), and T1-relaxation time mapping based on flip-angle array). A total of 104 regions of interest were defined on FLAIR images in WMH and normal appearing white matter (NAWM). Neuropathological examination included (semiquantitative assessment of axonal density (Bodian), myelin density (LFB), astrogliosis (GFAP) and microglial activation (HLA-DR). Patient groups (Alzheimer's disease versus controls) and tissue types (WMH versus NAWM) were compared with respect to QMRI and neuropathological measures. Overall, Alzheimer's disease patients had significantly lower FA ( P < 0.01) and higher T1-values than controls ( P = 0.04). WMH showed lower FA ( P < 0.01) and higher T1-values ( P < 0.001) than NAWM in both patient groups. A significant interaction between patient group and tissue type was found for the T1 measurements, indicating that the difference in T1-relaxation time between NAWM and WMH was larger in Alzheimer's disease patients than in non-demented controls. All neuropathological measures showed differences between WMH and NAWM, although the difference in microglial activation was specific for Alzheimer's disease. Multivariate regression models revealed that in Alzheimer's disease, axonal density was an independent determinant of FA, whereas T1 was independently determined by axonal and myelin density and microglial activation. Quantitative MRI techniques reveal differences in WMH between Alzheimer's disease and non-demented elderly, and are able to reflect the severity of the neuropathological changes involved.

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