The relationship between diffusion heterogeneity and microstructural changes in high-grade gliomas using Monte Carlo simulations

Molecular Imaging with Aquaporin-Based Reporter Genes: Quantitative Considerations from Monte Carlo Diffusion Simulations

“…The current study has limitations, which suggest potential avenues for future research. First, the two-compartment model employed here, similar to those used in past diffusion modeling studies, ,,, could be amended to include additional water pools for subcellular structures such as the nucleus and extracellular structures such as the vasculature. ,, Such multicompartment models could help in analyzing how Aqp1 behaves in systems in which nuclear and/or vascular volume fractions vary, which could in turn modify intra- and extracellular diffusion coefficients. Our framework can also be readily adapted to incorporate varying levels of Aqp1 expression achieved in different cell types or transgene expression systems by selecting an appropriate radius and permeability coefficient, which are easily measured experimentally.…”

“…33,38 In cancer biology, Monte Carlo methods have been used to explore the effects of cell size, packing density, and compartment volume fractions on tumor diffusion. 27,32 We recently applied Monte Carlo diffusion simulations to generate ground-truth diffusion data sets, which we used to compare the accuracies of various analytical models for estimating tissue microstructure using diffusion-weighted MRI. 36 In this study, we developed and experimentally validated a Monte Carlo simulator to model water diffusion in cells engineered to express Aqp1.…”

“…Monte Carlo diffusion simulations, which compute the Brownian motion of water molecules in the presence of a dephasing magnetic field gradient, are widely used to investigate the correlation between molecular diffusion of water and tissue morphology. − For example, Monte Carlo simulations have been used to quantify changes in white matter diffusivity caused by the swelling and beading of neurites during ischemic stroke. , In cancer biology, Monte Carlo methods have been used to explore the effects of cell size, packing density, and compartment volume fractions on tumor diffusion. , We recently applied Monte Carlo diffusion simulations to generate ground-truth diffusion data sets, which we used to compare the accuracies of various analytical models for estimating tissue microstructure using diffusion-weighted MRI …”

Molecular imaging with aquaporin-based reporter genes: quantitative considerations from Monte Carlo diffusion simulations

“…To expand Aqp1 into a broadly useful reporter for deep-tissue imaging, we need a mechanistic framework that predicts how changes in molecular diffusivity induced by Aqp1 expression are affected by cell radius, packing density, and the volume fraction of Aqp1-expressing cells. Monte Carlo diffusion simulations, which compute the Brownian motion of water molecules in the presence of a dephasing magnetic field gradient, are widely used to investigate the correlation between molecular diffusion of water and tissue morphology [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] . For example, Monte Carlo simulations have been used to quantify changes in white matter diffusivity caused by the swelling and beading of neurites during ischemic stroke 33,38 .…”

“…For example, Monte Carlo simulations have been used to quantify changes in white matter diffusivity caused by the swelling and beading of neurites during ischemic stroke 33,38 . In cancer biology, Monte Carlo methods have been used to explore the effects of cell size, packing density, and compartment volume fractions on tumor diffusion 27,32 . We recently applied Monte Carlo diffusion simulations to generate ground-truth diffusion datasets, which we used to compare the accuracies of various analytical models for estimating tissue microstructure using diffusion-weighted MRI 36 .…”