Design and Validation of Diffusion MRI Models of White Matter

  title={Design and Validation of Diffusion MRI Models of White Matter},
  author={Ileana O. Jelescu and Matthew D. Budde},
  journal={Frontiers in physics},
Diffusion MRI is arguably the method of choice for characterizing white matter microstructure in vivo. Over the typical duration of diffusion encoding, the displacement of water molecules is conveniently on a length scale similar to that of the underlying cellular structures. Moreover, water molecules in white matter are largely compartmentalized which enables biologically-inspired compartmental diffusion models to characterize and quantify the true biological microstructure. A plethora of… 

Figures and Tables from this paper

In vivo diffusion magnetic resonance imaging of the white matter microstructure from dictionaries generated by Monte Carlo simulations: development and validation
A general framework which leverages Monte Carlo simulations for the estimation of physically interpretable microstructural parameters such as indices of axon diameter and density, both in single and in crossing fascicles of axons, with no restriction on the data acquisition protocol is proposed.
Estimating axial diffusivity in the NODDI model
To estimate microstructure-related parameters from diffusion MRI data, biophysical models make strong, simplifying assumptions about the underlying tissue. The extent to which many of these
Applying biophysical models to understand the role of white matter in cognitive development
The hypothesis that previously reported correlations between reading skill and diffusion anisotropy in the corpus callosum reflect increased axon density in poor readers is tested and both models support this interpretation, highlighting the utility of biophysical models for testing specific hypotheses about cognitive development.
Transient Anomalous Diffusion MRI in Excised Mouse Spinal Cord: Comparison Among Different Diffusion Metrics and Validation With Histology
The results elucidate the biophysical mechanism underpinning tAD parameters and show the clinical potential of tAD-imaging, considering that both physiologic and pathologic neurodegeneration translate into alterations of WM morphometry and topology.
Quantifying brain microstructure with diffusion MRI: Theory and parameter estimation
We review, systematize and discuss models of diffusion in neuronal tissue, by putting them into an overarching physical context of coarse‐graining over an increasing diffusion length scale. From this
Optimizing the intrinsic parallel diffusivity in NODDI: An extensive empirical evaluation
Purpose NODDI is widely used in parameterizing microstructural brain properties. The model includes three signal compartments: intracellular, extracellular, and free water. The neurite compartment
Multidimensional Diffusion MRI Methods With Confined Subdomains
This work provides the basis for incorporating a model that takes confinement into account and possesses a diffusion time-dependence closer to that of restricted diffusion into two multidimensional diffusion MRI methods, and attempts to recover a confinement tensor distribution (CTD) on a human brain dataset.


Complex geometric models of diffusion and relaxation in healthy and damaged white matter
The reproducibility of simulations of diffusion in complex geometries is presented and the framework is quantitative, does not require specialized hardware, is easily implemented with little programming experience, and is freely available as open‐source software.
Degeneracy in model parameter estimation for multi‐compartmental diffusion in neuronal tissue
The results suggest that theBiophysical interpretation of dMRI model parameters crucially depends on establishing which of the minima is closer to the biophysical reality and the size of the uncertainty associated with each parameter.
Universal power-law scaling of water diffusion in human brain defines what we see with MRI
The observation of a universal power-law scaling of the dMRI signal identifies the contribution from water specifically confined inside narrow impermeable axons, validating the overarching assumption behind models of diffusion in neuronal tissue.
Estimation of Extracellular Volume from Regularized Multi-shell Diffusion MRI
This work adds low b-value shells to a regular DTI acquisition and presents methods to improve the estimation of the model parameters using the extra information, and defines a Laplace-Beltrami regularization operator that further stabilizes the multi-shell estimation.
White matter characterization with diffusional kurtosis imaging
Histological validation of high-resolution DTI in human post mortem tissue
A very good agreement was found between DTI and myelin orientations with the majority of voxels showing angular differences less than 10°, which has potentially important implications for tractography algorithms applied to high resolution diffusion MRI data if the aim is to move across the gray/white matter boundary.