The interplay between exchange and microscopic kurtosis as measured by diffusion MRI with double diffusion encoding: Theory and simulations DOI Creative Commons
Arthur Chakwizira, Filip Szczepankiewicz, Markus Nilsson

et al.

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: July 29, 2024

Abstract Double diffusion encoding (DDE) makes MRI sensitive to a wide range of microstructural features, and the acquired data can be analysed using different approaches. Correlation tensor imaging (CTI) uses DDE resolve three components diffusional kurtosis: isotropic, anisotropic, microscopic. The microscopic kurtosis is estimated from contrast between single (SDE) parallel signals at same b-value. Another approach multi-Gaussian exchange (MGE), which employs measure exchange. Sensitivity obtained by contrasting SDE CTI MGE exploit signal quantify exchange, this study investigates interplay these two quantities. We perform Monte-Carlo simulations in geometries with varying levels behaviour parameters MGE. conclude that rate. In an attempt separate we propose heuristic representation referred as µMGE (MGE incorporating kurtosis) accounts for both effects, exploiting distinct signatures mixing time: causes dependence on time while does not. find applying multiple times orthogonal allows estimation well all sources kurtosis.

Language: Английский

Investigating exchange, structural disorder, and restriction in gray matter via water and metabolites diffusivity and kurtosis time-dependence DOI Creative Commons
Eloïse Mougel, Julien Valette, Marco Palombo

et al.

Imaging Neuroscience, Journal Year: 2024, Volume and Issue: 2, P. 1 - 14

Published: March 18, 2024

Abstract Water diffusion-weighted MRI is a very powerful tool for probing tissue microstructure, but disentangling the contribution of compartment-specific structural disorder from cellular restriction and inter-compartment exchange remains an open challenge. In this work, we use MR spectroscopy (dMRS) water metabolite as function diffusion time in vivo mouse gray matter to shed light on: i) which these concomitant mechanisms (structural disorder, restriction, exchange) dominates measurements ii) with specific signature. We report time-dependence excellent SNR conditions provided by dMRS, up long (500 ms). kurtosis decreases increasing time, showing influence both exchange. However, despite experimental conditions, were not able clearly identify nature (i.e., 1D versus 2D/3D short-range disorder). Measurements purely intracellular metabolites (up 500 ms) show opposite behavior water, time. that signature restricted space, microstructural features such soma’s cell projections’ size can be estimated. Finally, comparing time-dependencies, attempt disentangle effect intra/extracellular extracellular space (both impacting only). Our results suggest relatively short (~1-50 (still unclear if or 2D/3D) most likely coming compartment. This work provides novel insights help interpret diffusion-time dependent terms underlying microstructure suggests may offer new way quantify restrictions matter.

Language: Английский

Citations

9
Diffusion MRI with double diffusion encoding and variable mixing times disentangles water exchange from transient kurtosis DOI Creative Commons
Arthur Chakwizira, Filip Szczepankiewicz, Markus Nilsson

et al.

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: March 13, 2025

Abstract Double diffusion encoding (DDE) makes MRI sensitive to a wide range of microstructural features, and the acquired data can be analysed using different approaches. Correlation tensor imaging (CTI) uses DDE resolve three components diffusional kurtosis: isotropic, anisotropic, microscopic kurtosis. The kurtosis is estimated from contrast between single (SDE) parallel signals at same b-value. Another approach multi-Gaussian exchange (MGE), which employs measure exchange. Sensitivity obtained by contrasting SDE CTI MGE exploit signal quantify exchange, this study investigates interplay these two quantities. We perform Monte Carlo simulations in geometries with varying levels behaviour parameters MGE. conclude that rate intercompartmental transient individual compartments are distinct sources In an attempt disentangle sources, we propose heuristic representation referred as tMGE (MGE incorporating kurtosis) accounts for both effects exploiting signatures mixing time: causes slow dependence on time while arguably has much faster dependence. find applying multiple times orthogonal may enable estimation well

Language: Английский

Citations

0
Linear rotationally invariant kurtosis measures from double diffusion encoding MRI DOI Creative Commons
Hunter G. Moss, Thorsten Feiweier, Andreana Benitez

et al.

Magnetic Resonance Imaging, Journal Year: 2025, Volume and Issue: unknown, P. 110399 - 110399

Published: April 1, 2025

To characterize the complete set of linear rotationally invariant kurtosis measures provided by double diffusion encoding (DDE) MRI, show their utility in distinguishing different types multiple Gaussian compartment (MGC) models, and demonstrate simplified acquisition analysis schemes for estimation. The lowest order novel information obtainable with DDE MRI can be encapsulated a six-dimensional tensor. most basic are rotational invariants that this tensor while depending on no other physical quantities. We identify four such any others must combinations these. applied to classify MGC models according whether they include microscopic anisotropy or intercompartmental water exchange. In addition, used investigate effect exchange estimates fractional (μFA). Simplified proposed demonstrated human brain data obtained at 3 T. For considered regions, found largely consistent having anisotropy. They also indicate gray matter may affect μFA. have exchange, estimated simple schemes. Measurements support validity importance modeling matter.

Language: Английский

Citations

0
Time-dependent diffusion magnetic resonance imaging: measurement, modeling, and applications DOI
Ruicheng Ba, Liyi Kang, Dan Wu

et al.

Journal of Zhejiang University. Science A, Journal Year: 2024, Volume and Issue: 25(10), P. 765 - 787

Published: Aug. 22, 2024

Language: Английский

Citations

2
Mean Kärger Model Water Exchange Rate in Brain DOI Creative Commons
Jens H. Jensen,

Joshua Voltin,

Maria F. Falangola

et al.

Imaging Neuroscience, Journal Year: 2024, Volume and Issue: 2, P. 1 - 16

Published: Jan. 1, 2024

Abstract Intercellular water exchange in brain is analyzed terms of the multi-compartment Kärger model (KM), and mean KM rate used as a summary statistic for characterizing processes. Prior work extended by deriving stronger lower bound that can be determined from time dependence diffusional kurtosis. In addition, an analytic formula giving kurtosis thin cylindrical neurites demonstrated, this applied to numerically test accuracy range parameters. Finally, measured vivo with imaging dorsal hippocampus cerebral cortex 8-month-old mice. From bound, found 46.1 ± 11.0 s-1 or greater 20.5 8.5 cortex.

Language: Английский

Citations

1
Investigating exchange, structural disorder and restriction in Gray Matter via water and metabolites diffusivity and kurtosis time-dependence DOI
Eloïse Mougel, Julien Valette, Marco Palombo

et al.

Proceedings on CD-ROM - International Society for Magnetic Resonance in Medicine. Scientific Meeting and Exhibition/Proceedings of the International Society for Magnetic Resonance in Medicine, Scientific Meeting and Exhibition, Journal Year: 2023, Volume and Issue: unknown

Published: Aug. 3, 2023

This work reports first-time measurements of the time-dependent diffusivity and kurtosis both water metabolites in vivo mouse gray matter (GM). Our aim is to exploit complementary information provided by diffusion intracellular investigate potentially disentangle role exchange, structural disorder restriction GM. results show evidence that diffusion-time dependence GM mostly driven 1D short-range disorder, alongside exchange. Conversely, metabolites’ exclusively cellular restrictions, paving a new way quantify noninvasively microstructural restrictions

Language: Английский

Citations

2
The interplay between exchange and microscopic kurtosis as measured by diffusion MRI with double diffusion encoding: Theory and simulations DOI Creative Commons
Arthur Chakwizira, Filip Szczepankiewicz, Markus Nilsson

et al.

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: July 29, 2024

Abstract Double diffusion encoding (DDE) makes MRI sensitive to a wide range of microstructural features, and the acquired data can be analysed using different approaches. Correlation tensor imaging (CTI) uses DDE resolve three components diffusional kurtosis: isotropic, anisotropic, microscopic. The microscopic kurtosis is estimated from contrast between single (SDE) parallel signals at same b-value. Another approach multi-Gaussian exchange (MGE), which employs measure exchange. Sensitivity obtained by contrasting SDE CTI MGE exploit signal quantify exchange, this study investigates interplay these two quantities. We perform Monte-Carlo simulations in geometries with varying levels behaviour parameters MGE. conclude that rate. In an attempt separate we propose heuristic representation referred as µMGE (MGE incorporating kurtosis) accounts for both effects, exploiting distinct signatures mixing time: causes dependence on time while does not. find applying multiple times orthogonal allows estimation well all sources kurtosis.

Language: Английский

Citations

0