Abstract 37: Increased Mean Transit Time and Blood Brain Permeability in Asymptomatic White Matter Lesions of Ischemic Origin

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Blake Dewey ◽  
Xiang Xu ◽  
Linda Knutson ◽  
Amod Jog ◽  
Jerry Prince ◽  
...  
Keyword(s):  
White Matter ◽  
Transit Time ◽  
Gray Matter ◽  
Mean Transit Time ◽  
White Matter Lesions ◽  
Lesion Volume ◽  
Dynamic Susceptibility ◽  
Automated Segmentation ◽  
Blood Brain ◽  
Significant Difference

Introduction: White matter lesions of presumed ischemic origin (WMH) have been associated with increased risk of stroke, cognitive and motor decline, and are a subject of public health research. Engineering new MRI pipelines allowing for determination of mean transit time (MTT), and blood brain barrier permeability (BBBP), within WMH lesions is required for long-term population-based studies of lesion progression in patients with dementia and vascular cognitive impairment. Methods: WMH lesion volumes in 24 asymptomatic individuals was determined using an automated segmentation methodology, S3DL, with manual correction to remove false positives. A double contrast injection scheme was used to measure both K trans using dynamic contrast enhanced (DCE) imaging and K 2 using dynamic susceptibility contrast (DSC) imaging which also provided perfusion-related measures. BBBP was measured as k 2 within segmented WMH lesions and compared with normal white and gray matter. Results: The mean transit time (MTT) was found to be significantly prolonged (8.11, p<0.001Wilcoxon Signed-Rank Test) in WMH lesions when compared to normal appearing white and gray matter. There was no significant difference in DCE-K trans (0.018, p=0.351) between the lesions and the white/gray matter. Permeability measured in the WMH lesions using the DSC-K 2 method was increased and was correlated withincreasing total WMH lesion volume (spearman correlation 0.44; p< 0.046). Conclusion: In this first study using an advanced WMH lesion automated segmentation pipeline, we measured DCE and DSC perfusion and permeability variables within WMH lesions and compared them to normal white and grey matter in healthy people. We observed increasing MTT, within WMH lesions as compared to unaffected white and gray matter. Using the DSC-K 2 method, BBBP was higher within WMH lesions in these asymptomatic people, and correlated with increasing total lesion volume.

Blood-brain Barrier Disruption May Contribute to White Matter Lesions in the Setting of Internal Jugular Venous Stenosis

2019 ◽  
Vol 16 (4) ◽  
pp. 328-334
Author(s):  
Yali Wu ◽  
Ran Meng ◽  
Gary B. Rajah ◽  
Yuchuan Ding ◽  
Yaoming Xu ◽  
...  
Keyword(s):  
White Matter ◽  
Blood Brain Barrier ◽  
Statistical Significance ◽  
White Matter Lesions ◽  
Brain Barrier ◽  
Control Group ◽  
Imaging Features ◽  
Blood Brain ◽  
Venous Stenosis ◽  
Significant Difference

Background and Purpose: Cloudy white matter lesions are associated imaging features of internal jugular venous stenosis (IJVS). However, the mechanism of the IJVS associated cloudy white matter lesions is still unclear. This study aims to evaluate blood-brain barrier integrity of the patients with IJVS. Materials and Methods: A total of 45 eligible patients with IJVS confirmed by computed tomography venography (CTV) and 45 healthy controls were enrolled into this study. The levels of serum MMP-9 and the markers of tight junctions, including occludin and ZO-1 obtained from IJVS patients and control group were tested by enzyme-linked immune-sorbent assay and compared. Results: Both the levels of serum MMP-9 (0.2ng/ml) and occludin (0.05ng/ml) in IJVS group were higher than in the control group (0.01ng/ml vs. 0 ng/ml, all p<0.001). While, the levels of serum ZO-1 showed no statistical significance between the two groups (0.55ng/ml vs 0.735ng/ml, P=0.34). The levels of serum MMP-9 between the subset with or without white matter lesions in IJVS group showed a significant difference (0.22 [0.06, 0.43] vs. 0.01 [0.01, 0.06], P =0.019). Conclusions: BBB disruption may participate in the formation of IJVS-associated white matter lesions; the mechanism of BBB disruption may involve MMP-9 and occludin.

scholarly journals Blood-brain barrier breakdown in non-enhancing multiple sclerosis lesions detected by 7-Tesla MP2RAGE ΔT1 mapping

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249973
Author(s):  
Seongjin Choi ◽  
Margaret Spini ◽  
Jun Hua ◽  
Daniel M. Harrison
Keyword(s):  
Multiple Sclerosis ◽  
Relaxation Time ◽  
White Matter ◽  
Blood Brain Barrier ◽  
White Matter Lesions ◽  
Brain Barrier ◽  
7 Tesla ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Blood Brain

Although the blood-brain barrier (BBB) is altered in most multiple sclerosis (MS) lesions, gadolinium enhancement is seen only in acute lesions. In this study, we aimed to investigate gadolinium-induced changes in T1 relaxation time in MS lesions on 7-tesla (7T) MRI as a means to quantify BBB breakdown in non-enhancing MS lesions. Forty-seven participants with MS underwent 7T MRI of the brain with a magnitude-prepared rapid acquisition of 2 gradient echoes (MP2RAGE) sequence before and after contrast. Subtraction of pre- and post-contrast T1 maps was used to measure T1 relaxation time change (ΔT1) from gadolinium. ΔT1 values were interrogated in enhancing white matter lesions (ELs), non-enhancing white matter lesions (NELs), and normal appearing white matter (NAWM) and metrics were compared to clinical data. ΔT1 was measurable in NELs (median: -0.139 (-0.304, 0.174) seconds; p < 0.001) and was negligible in NAWM (median: -0.001 (-0.036, 0.155) seconds; p = 0.516). Median ΔT1 in NELs correlated with disability as measured by Expanded Disability Status Scale (EDSS) (rho = -0.331, p = 0.026). Multiple measures of NEL ΔT1 variability also correlated with EDSS. NEL ΔT1 values were greater and more variable in patients with progressive forms of MS and greater in those not on MS treatment. Measurement of the changes in T1 relaxation time caused by contrast on 7T MP2RAGE reveals clinically relevant evidence of BBB breakdown in NELs in MS. This data suggests that NEL ΔT1 should be evaluated further as a biomarker for disease severity and treatment effect in MS.

scholarly journals The effect of carotid artery stenting on capillary transit time heterogeneity in patients with carotid artery stenosis

2018 ◽  
Vol 3 (3) ◽  
pp. 263-271 ◽  
Author(s):  
Ethem M Arsava ◽  
Mikkel B Hansen ◽  
Berkan Kaplan ◽  
Ahmet Peker ◽  
Rahsan Gocmen ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Transit Time ◽  
Carotid Artery Stenting ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Oxygen Extraction Fraction ◽  
Consecutive Series ◽  
Dynamic Susceptibility ◽  
Dynamic Susceptibility Contrast ◽  
Vascular Events

Introduction Carotid revascularisation improves haemodynamic compromise in cerebral circulation as an additional benefit to the primary goal of reducing future thromboembolic risk. We determined the effect of carotid artery stenting on cerebral perfusion and oxygenation using a perfusion-weighted MRI algorithm that is based on assessment of capillary transit-time heterogeneity together with other perfusion and metabolism-related metrics. Patients and methods A consecutive series of 33 patients were evaluated by dynamic susceptibility contrast perfusion-weighted MRI prior to and within 24 h of the endovascular procedure. The level of relative change induced by stenting, and relationship of these changes with respect to baseline stenosis degree were analysed. Results Stenting led to significant increase in cerebral blood flow ( p < 0.001), and decrease in cerebral blood volume ( p = 0.001) and mean transit time ( p < 0.001); this was accompanied by reduction in oxygen extraction fraction ( p < 0.001) and capillary transit-time heterogeneity ( p < 0.001), but an overall increase in relative capillary transit-time heterogeneity (RTH: CTH divided by MTT; p = 0.008). No significant change was observed with respect to cerebral metabolic rate of oxygen. The median volume of tissue with MTT > 2s decreased from 24 ml to 12 ml ( p = 0.009), with CTH > 2s from 29 ml to 19 ml ( p = 0.041), and with RTH < 0.9 from 61 ml to 39 ml ( p = 0.037) following stenting. These changes were correlated with the baseline degree of stenosis. Discussion: Stenting improved the moderate stage of haemodynamic compromise at baseline in our cohort. The decreased relative transit-time heterogeneity, which increases following stenting, is probably a reflection of decreased functional capillary density secondary to chronic hypoperfusion induced by the proximal stenosis. Conclusion: Carotid artery stenting, is not only important for prophylaxis of future vascular events, but also is critical for restoration of microvascular function in the cerebral tissue.

scholarly journals White matter lesions and brain gray matter volume in cognitively normal elders

2012 ◽  
Vol 33 (4) ◽  
pp. 834.e7-834.e16 ◽  
Author(s):  
Cyrus A. Raji ◽  
Oscar L. Lopez ◽  
Lewis H. Kuller ◽  
Owen T. Carmichael ◽  
William T. Longstreth ◽  
...  
Keyword(s):  
White Matter ◽  
Gray Matter ◽  
Gray Matter Volume ◽  
White Matter Lesions ◽  
Cognitively Normal ◽  
Matter Volume

scholarly journals Reliable Estimation of Capillary Transit Time Distributions Using DSC-MRI

2014 ◽  
Vol 34 (9) ◽  
pp. 1511-1521 ◽  
Author(s):  
Kim Mouridsen ◽  
Mikkel Bo Hansen ◽  
Leif Østergaard ◽  
Sune Nørhøj Jespersen
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Transit Time ◽  
Neuronal Response ◽  
Mean Transit Time ◽  
Oxygen Extraction Fraction ◽  
Dynamic Susceptibility ◽  
Arterial Blood ◽  
Dsc Mri ◽  
Wide Range

The regional availability of oxygen in brain tissue is traditionally inferred from the magnitude of cerebral blood flow ( CBF) and the concentration of oxygen in arterial blood. Measurements of CBF are therefore widely used in the localization of neuronal response to stimulation and in the evaluation of patients suspected of acute ischemic stroke or flow-limiting carotid stenosis. It was recently demonstrated that capillary transit time heterogeneity ( CTH) limits maximum oxygen extraction fraction ( OEFmax) that can be achieved for a given CBF. Here we present a statistical approach for determining CTH, mean transit time ( MTT), and CBF using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI). Using numerical simulations, we demonstrate that CTH, MTT, and OEFmax can be estimated with low bias and variance across a wide range of microvascular flow patterns, even at modest signal-to-noise ratios. Mean transit time estimated by singular value decomposition (SVD) deconvolution, however, is confounded by CTH. The proposed technique readily identifies malperfused tissue in acute stroke patients and appears to highlight information not detected by the standard SVD technique. We speculate that this technique permits the non-invasive detection of tissue with impaired oxygen delivery in neurologic disorders such as acute ischemic stroke and Alzheimer's disease during routine diagnostic imaging.

scholarly journals Long-term cerebral white and gray matter changes after preeclampsia

Neurology ◽  
2017 ◽  
Vol 88 (13) ◽  
pp. 1256-1264 ◽  
Author(s):  
Timo Siepmann ◽  
Henry Boardman ◽  
Amy Bilderbeck ◽  
Ludovica Griffanti ◽  
Yvonne Kenworthy ◽  
...  
Keyword(s):  
Cardiovascular Risk ◽  
White Matter ◽  
Temporal Lobe ◽  
Gray Matter ◽  
Diffusion Tensor ◽  
Brain Mri ◽  
Risk Profile ◽  
Lesion Volume ◽  
Cardiovascular Risk Profile ◽  
Microstructural Integrity

Objective:To determine whether changes in cerebral structure are present after preeclampsia that may explain increased cerebrovascular risk in these women.Methods:We conducted a case control study in women between 5 and 15 years after either a preeclamptic or normotensive pregnancy. Brain MRI was performed. Analysis of white matter structure was undertaken using voxel-based segmentation of fluid-attenuation inversion recovery sequences to assess white matter lesion volume and diffusion tensor imaging to measure microstructural integrity. Voxel-based analysis of gray matter volumes was performed with adjustment for skull size.Results:Thirty-four previously preeclamptic women (aged 42.8 ± 5.1 years) and 49 controls were included. Previously preeclamptic women had reduced cortical gray matter volume (523.2 ± 30.1 vs 544.4 ± 44.7 mL, p < 0.05) and, although both groups displayed white matter lesions, changes were more extensive in previously preeclamptic women. They displayed increased temporal lobe white matter disease (lesion volume: 23.2 ± 24.9 vs 10.9 ± 15.0 μL, p < 0.05) and altered microstructural integrity (radial diffusivity: 538 ± 19 vs 526 ± 18 × 10−6 mm2/s, p < 0.01), which also extended to occipital and parietal lobes. The degree of temporal lobe white matter change in previously preeclamptic women was independent of their current cardiovascular risk profile (p < 0.05) and increased with time from index pregnancy (p < 0.05).Conclusion:A history of preeclampsia is associated with temporal lobe white matter changes and reduced cortical volume in young women, which is out of proportion to their classic cardiovascular risk profile. The severity of changes is proportional to time since pregnancy, which would be consistent with continued accumulation of damage after pregnancy.

scholarly journals The effect of hypointense white matter lesions on automated gray matter segmentation in multiple sclerosis

2011 ◽  
Vol 33 (12) ◽  
pp. 2802-2814 ◽  
Author(s):  
Rose Gelineau-Morel ◽  
Valentina Tomassini ◽  
Mark Jenkinson ◽  
Heidi Johansen-Berg ◽  
Paul M. Matthews ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Gray Matter ◽  
White Matter Lesions
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