Lesion Explorer: A comprehensive segmentation and parcellation package to obtain regional volumetrics for subcortical hyperintensities and intracranial tissue

Ramı́rez, Joel; Gibson, Erin; Quddus, Abdul; Lobaugh, Nancy J.; Feinstein, Anthony; Levine, Brian; Scott, Christopher J.; Levy‐Cooperman, Naama; Gao, Fuqiang; Black, Sandra E.

doi:10.1016/j.neuroimage.2010.09.013

Cited by 119 publications

(144 citation statements)

References 61 publications

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“…This commonly found trough of signal intensity at the PVWMH rim may mark the boundary of the periventricular white matter hyperintensities and DWMH distinction and may conform to a dichotomy on the basis of rules of continuity to the ventricle. 6,7 This distinction, less informative than advanced distributional probabilistic atlases, has proved valid in clinical practice and research. We found a positive and significant association between PVWMH width and hypertension, which is a small-vessel disease risk factor considered to be more highly associated with DWMH.…”

Section: Discussionmentioning

confidence: 99%

“…Despite the fact that visual assessment and categorization of PVWMH in "borderline" cases were discussed and agreed on between the 2 observers, the distinction from 1 category to another was not clear in some cases. Also, because WMH segmentations and volumes were not divided into periventricular white matter hyperintensities and DWMH as previous investigators have done, 7,12 the associations of WMH volume with other parameters are not sensitive to differences between periventricular white matter hyperintensities and DWMH. Another limitation is that the data used in our analysis merely indicated whether the vascular risk factor was present or absent, not allowing detailed analyses of these variables (such as blood pressure measurement) as performed by other investigators.…”

Section: Discussionmentioning

confidence: 99%

“…The 3D visualization techniques presented here and in other studies 7 should be explored further in studies of WMH to clarify the spatial distribution of WMH, enabling stronger conclusions about defining subtypes, etiology, and progression. This study supports the contention that 3D analysis avoids some of the limitations of 2D axial analysis, 12 which allowed identifying otherwise undetected fragmented patterns of PVWMH.…”

Section: Recommendations For Further Investigationmentioning

confidence: 98%

“…5 However, no evidence has been provided to support these conventions. The criteria for separating WMH into PVWMH or DWMH have typically relied on rules of continuity of WMH from the lateral ventricles, 6,7 but distance from the ventricular edges has also been proposed. For example, PVWMH have been reported to penetrate as much as 7 and 13 mm into the brain parenchyma, 8,9 and any WMH found within 3 mm from the ventricular wall have been proposed to belong to a distinct subtype, "juxtaperiventricular."…”

mentioning

confidence: 99%

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Morphologic, Distributional, Volumetric, and Intensity Characterization of Periventricular Hyperintensities

Hernández

Piper²,

Bastin

et al. 2013

AJNR Am J Neuroradiol

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Recommendations For Further Investigationmentioning

confidence: 98%

mentioning

confidence: 99%

See 2 more Smart Citations

Morphologic, Distributional, Volumetric, and Intensity Characterization of Periventricular Hyperintensities

Hernández

Piper²,

Bastin

et al. 2013

AJNR Am J Neuroradiol

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“…Segmentation of WMH was performed using the Lesion Explorer processing pipeline. 25,26 T1-weighted anatomical images were segmented into CSF, gray matter, and white matter using SPM8 (Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College, London, UK). A diamond-shaped structuring element was used to erode the white matter segmentation in 5 iterations at the resolution of the T1-weighted image to prevent partial volume effects.…”

Section: Methods Participant Recruitment and Assessmentmentioning

confidence: 99%

Cerebrovascular reactivity and white matter integrity

et al. 2016

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Objective: To compare the diffusion and perfusion MRI metrics of normal-appearing white matter (NAWM) with and without impaired cerebrovascular reactivity (CVR).Methods: Seventy-five participants with moderate to severe leukoaraiosis underwent blood oxygen level-dependent CVR mapping using a 3T MRI system with precise carbon dioxide stimulus manipulation. Several MRI metrics were statistically compared between areas of NAWM with positive and negative CVR using one-way analysis of variance with Bonferroni correction for multiple comparisons.Results: Areas of NAWM with negative CVR showed a significant reduction in fractional anisotropy by a mean (SD) of 3.7% (2.4), cerebral blood flow by 22.1% (8.2), regional cerebral blood volume by 22.2% (7.0), and a significant increase in mean diffusivity by 3.9% (3.1) and time to maximum by 10.9% (13.2) (p , 0.01), compared to areas with positive CVR.Conclusions: Impaired CVR is associated with subtle changes in the tissue integrity of NAWM, as evaluated using several quantitative diffusion and perfusion MRI metrics. These findings suggest that impaired CVR may contribute to the progression of white matter disease. Changes in the periventricular and subcortical white matter are observed on both CT and MRI scans of elderly individuals.1 The affected areas appear hyperintense on T2-weighted MRI, and are labeled as white matter hyperintensities (WMHs) if they are of presumed vascular origin. 2They are associated with an increased risk of dementia, 3 stroke, 4 and cognitive disability, 5 and correlated with age; as many as 95% of individuals over age 50 have WMHs.6,7 Therefore, preventing or slowing the progression of WMHs has the potential to lower the disease burden. Although several modifiable risk factors have been associated with WMH progression, such as smoking and high blood pressure, 8 the detailed pathogenesis of WMHs remains controversial. Nevertheless, the prevailing view is that a chronic low-grade ischemic injury is the final common pathway for these lesions, 9,10 and this view was the motivation for our study. Accordingly, this study characterized vascular pathophysiology in normal-appearing white matter (NAWM) before progression to overt leukoaraiosis by measuring cerebrovascular reactivity (CVR); the change in cerebral blood flow in response to a vasodilatory stimulus. Negative CVR values represent steal physiology, in which blood flow is redistributed from regions of exhausted cerebral vasodilatory reserve to areas with preserved vasodilatory capacity. 11 WeFrom the Department of Physiology

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Vascular burden and cognition: Mediating roles of neurodegeneration and amyloid PET

Ottoy

Ozzoude

Zukotynski

et al. 2022

Alzheimer's & Dementia

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It remains unclear to what extent cerebrovascular burden relates to amyloid beta (Aβ) deposition, neurodegeneration, and cognitive dysfunction in mixed disease populations with small vessel disease and Alzheimer's disease (AD) pathology. In 120 subjects, we investigated the association of vascular burden (white matter hyperintensity [WMH] volumes) with cognition. Using mediation analyses, we tested the indirect effects of WMH on cognition via Aβ deposition ( 18 F-AV45 positron emission tomography [PET]) and neurodegeneration (cortical thickness or 18 F fluorodeoxyglucose PET)in AD signature regions. We observed that increased total WMH volume was associated with poorer performance in all tested cognitive domains, with the strongest effects observed for semantic fluency. These relationships were mediated mainly via cortical thinning, particularly of the temporal lobe, and to a lesser extent serially mediated via Aβ and cortical thinning of AD signature regions. WMH volumes differentially impacted cognition depending on lobar location and Aβ status. In summary, our study suggests mainly an amyloid-independent pathway in which vascular burden affects cognitive function via localized neurodegeneration.

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Lesion Explorer: A comprehensive segmentation and parcellation package to obtain regional volumetrics for subcortical hyperintensities and intracranial tissue

Cited by 119 publications

References 61 publications

Morphologic, Distributional, Volumetric, and Intensity Characterization of Periventricular Hyperintensities

Morphologic, Distributional, Volumetric, and Intensity Characterization of Periventricular Hyperintensities

Cerebrovascular reactivity and white matter integrity

Vascular burden and cognition: Mediating roles of neurodegeneration and amyloid PET

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