Dynamic diffusion-weighted imaging of intracranial cardiac impulse propagation along arteries to arterioles in the aging brain

Journal of Cerebral Blood Flow & Metabolism, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 13, 2025

Intracranial cardiac impulse propagation along penetrating arterioles is vital for both nutrient supply via blood circulation and waste clearance CSF circulation. However, current neuroimaging methods are limited to simultaneously detecting at pial arteries, arterioles, between them. We hypothesized that this could be detected paravascular dynamics it may change with aging. Using dynamic diffusion-weighted imaging (dynDWI), we oscillatory motion synchronized the finger photoplethysmography in subarachnoid space (SAS) cerebral cortex, a delay revealing an pathway from SAS averaging 84 milliseconds. Data 70 subjects aged 18 85 years showed bimodal age-related SAS-Cortex travel time: initially increases age, peaks around 45 years, then decreases. Computational biomechanical modeling of cardiovascular system was performed replicated 84-millisecond delay. Sensitivity analysis suggests variations time primarily driven by changes arteriolar compliance. These findings support use dynDWI measuring intracranial highlight its potential assessing related vascular functions.

Language: Английский

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The pulsing brain: state of the art and an interdisciplinary perspective

Interface Focus, Journal Year: 2025, Volume and Issue: 15(1)

Published: April 4, 2025

Understanding the pulsing dynamics of tissue and fluids in intracranial environment is an evolving research theme aimed at gaining new insights into brain physiology disease progression. This article provides overview related magnetic resonance imaging, ultrasound medical diagnostics mathematical modelling biological tissues fluids. It highlights recent developments, illustrates current goals emphasizes importance collaboration between these fields.

Language: Английский

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Assessing the feasibility of a new approach to measure the full spectrum of cerebrospinal fluid dynamics within the human brain using MRI: insights from a simulation study

Interface Focus, Journal Year: 2025, Volume and Issue: 15(1)

Published: April 4, 2025

Cerebrospinal fluid (CSF) dynamics are essential in the waste clearance of brain. Disruptions CSF flow linked to various neurological conditions, highlighting need for accurate measurement its dynamics. Current methods typically capture high-speed movements or focus on a single-frequency component, presenting challenges comprehensive analysis. This study proposes novel approach using displacement encoding with stimulated echoes (DENSE) MRI assess full spectrum motion within Through simulations, we evaluated feasibility disentangling distinct components, including heartbeat- and respiration-driven flows, as well net velocity component due continuous turnover, tested performance our method under incorrect assumptions about underlying model motion. Results demonstrate that DENSE can accurately separate these reliably estimate velocity, even when periodic physiological motions vary over time. The proved be robust low-frequency nature missing components model. offers technique quantifying dynamics, advancing understanding relative role drivers brain clearance.

Language: Английский

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Coupled pulsatile vascular and paravascular fluid dynamics in the human brain

Fluids and Barriers of the CNS, Journal Year: 2024, Volume and Issue: 21(1)

Published: Sept. 11, 2024

Language: Английский

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Transmantle pressure under the influence of free breathing: non-invasive quantification of the aqueduct pressure gradient in healthy adults

Fluids and Barriers of the CNS, Journal Year: 2025, Volume and Issue: 22(1)

Published: Jan. 3, 2025

Language: Английский

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Genome-wide and phenome-wide studies provided insights into brain glymphatic system function and its clinical associations

Science Advances, Journal Year: 2025, Volume and Issue: 11(3)

Published: Jan. 17, 2025

We applied an MRI technique diffusion tensor imaging along the perivascular space (DTI-ALPS) for assessing glymphatic system (GS) in a genome-wide association study (GWAS) and phenome-wide (PheWAS) of 40,486 European individuals. Exploratory analysis revealed 17 genetic loci significantly associating with regional DTI-ALPS index. found 58 genes, including SPPL2C EFCAB5 , which prioritized index subtypes associated neurodegenerative diseases. PheWAS 241 traits suggested that body mass blood pressure phenotypes closely related to GS function. Moreover, we detected disrupted function 44 625 predefined disease conditions. Notably, Mendelian randomization mediation indicated lower was risk factor ischemic stroke (odds ratio = 1.56, P 0.028) by partly mediating obesity. Results provide insights into architecture mechanism DIT-ALPS highlight its great clinical value, especially cerebral stroke.

Language: Английский

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Cerebrospinal Fluid Flow within Ventricles and Subarachnoid Space Evaluated by Velocity Selective Spin Labeling MRI

NeuroImage, Journal Year: 2025, Volume and Issue: unknown, P. 121095 - 121095

Published: Feb. 1, 2025

This study aims to evaluate cerebrospinal fluid (CSF) flow dynamics within ventricles, and the subarachnoid space (SAS) using velocity selective spin labeling (VSSL) MRI method with Fourier-transform-based inversion preparation. The included healthy volunteers who underwent scanning specific VSSL parameters optimized for CSF quantification. sequence was calibrated against phase-contrast (PC-MRI) ensure accurate measurements. patterns observed in ventricles were consistent those obtained 3D amplified other advanced techniques, verifying reliability of method. successfully measured SAS along major arteries, including middle cerebral artery (MCA), anterior (ACA), posterior (PCA), an average 0.339±0.117cm/s. diffusion component well suppressed by flow-compensated gradients, enabling comprehensive mapping rapid pattern system ventricles. closely resembles recently discovered perivascular (PVSAS) system. around MCA, PCA, ACA arteries exhibited a weak orientation dependency. also measured, of0.309±0.116cm/s, highest superior-inferior direction. underscores potential as non-invasive tool investigating both

Language: Английский

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Congenital external hydrocephalus: A rare presentation of lobar holoprosencephaly in a neonate

Radiology Case Reports, Journal Year: 2025, Volume and Issue: 20(5), P. 2323 - 2327

Published: March 8, 2025

Language: Английский

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Alterations in Cerebrospinal Fluid Motion After Mild Traumatic Brain Injury: An Intravoxel Incoherent Motion Magnetic Resonance Imaging Analysis

Research Square (Research Square), Journal Year: 2025, Volume and Issue: unknown

Published: April 17, 2025

Purpose: To investigate alterations in cerebrospinal fluid (CSF) motion following mild traumatic brain injury (TBI) using intravoxel incoherent (IVIM) magnetic resonance imaging (MRI) and compare regional CSF dynamics between patients with TBI healthy controls. Methods: In this prospective observational study, 14 controls underwent IVIM MRI a 3-Tesla scanner. The f-value, which reflects microfluidic motion, was calculated 33 manually defined regions of interest, including the supratentorial, infratentorial, parenchymal areas. We analyzed group differences f-values assessed longitudinal data from three for temporal changes motion. Results: Compared to controls, showed significantly higher infratentorial regions, particularly left cerebellopontine angle (p=0.0038), tendency toward lower supratentorial such as lateral ventricle right frontal subarachnoid space. Longitudinal analysis cases revealed increasing over time, suggesting recovery trauma-induced suppression, while either decreased or remained stable. One patient who surgical decompression increased f-value during chronic phase. Conclusion: This study provides preliminary evidence that induces region-specific activities acute suggest partial dynamics, although interventionmay modulate these patterns. IVIM-MRI may serve novel tool detecting posttraumatic abnormalities guide future investigations on their clinical relevance.

Language: Английский

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The heartbeat induces local volumetric compression in the healthy human brain: a 7 T magnetic resonance imaging study on brain tissue pulsations

Interface Focus, Journal Year: 2024, Volume and Issue: 14(6)

Published: Dec. 6, 2024

Intracerebral blood volume changes along the cardiac cycle cause volumetric strain in brain tissue, measurable with displacement encoding stimulated echoes (DENSE) magnetic resonance imaging. Individual maps show compressing and expanding voxels, raising question whether systolic compressions reflect a physiological phenomenon. In DENSE data from nine healthy volunteers, voxels were grouped into three clusters according to tissue mask excluding extracerebral vessels cerebrospinal fluid using two-stage clustering approach. To confirm source of compressions, patient cranial opening was analysed. Spatial patterns matched high-resolution anatomical scans, acquired one additional individual. All subjects consistently showed cluster compressive during systole, covering 10.2% [7.3−13.1%] (mean [95% confidence interval]) mask, besides two expansion clusters. patient, no compression observed. Although did not co-localize intracerebral veins or perivascular spaces on first-stage results suggested that distinction between has (peri)vascular source. conclusion, shows heartbeat-induced possibly indicating porous structures such as spaces.

Language: Английский

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