Time-Dependent Diffusion of Water in a Biological Model System
TLDR
A pulsed-field-gradient spin echo NMR technique is used to measure the time-dependent diffusion coefficient D(t) in packed erythrocytes, which may explain the drop in D(eff) during the early stages of brain ischemia, where just minutes after an ischemic insult the extra-cellular volume in the affected region of the brain is significantly reduced.Abstract:
Packed erythrocytes are ideally suited as a model system for the study of water diffusion in biological tissue, because cell size, membrane permeability, and extracellular volume fraction can be varied independently. We used a pulsed-field-gradient spin echo NMR technique to measure the time-dependent diffusion coefficient D(t) in packed erythrocytes. The long-time diffusion constant, D(eff), depends sensitively on the extracellular volume fraction. This may explain the drop in D(eff) during the early stages of brain ischemia, where just minutes after an ischemic insult the extra-cellular volume in the affected region of the brain is significantly reduced. Using an effective medium formula, we estimate the erythrocyte membrane permeability, in good agreement with measurements on isolated cells. From the short-time behavior of D(t), we determine the surface-to-volume ratio of the cells, approximately (0.72 micron)-1.read more
Citations
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Diffusion in brain extracellular space.
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MRI quantification of non-Gaussian water diffusion by kurtosis analysis.
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References
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Book
Advanced mathematical methods for scientists and engineers
Carl M. Bender,Steven A. Orszag +1 more
TL;DR: A self-contained presentation of the methods of asymptotics and perturbation theory, methods useful for obtaining approximate analytical solutions to differential and difference equations is given in this paper.
Journal ArticleDOI
Early detection of regional cerebral ischemia in cats: comparison of diffusion- and T2-weighted MRI and spectroscopy.
Michael E. Moseley,Yoram Cohen,J Mintorovitch,Laureano Chileuitt,Hiroaki Shimizu,John Kucharczyk,Michael F. Wendland,Philip Weinstein +7 more
TL;DR: Diffusion‐weighted hyperintensity in ischemic tissues may be temperature‐related, due to rapid accumulation of diffusion‐restricted water in the intracellular space (cytotoxic edema) resulting from the breakdown of the transmembrane pump and/or to microscopic brain pulsations.
Journal ArticleDOI
Diffusion in Embryogenesis
TL;DR: A simple order-of-magnitude calculation suggests that diffusion may be the underlying mechanism in establishing morphogenetic gradients in embryonic development.
Journal ArticleDOI
Diffusion propagator as a probe of the structure of porous media
Partha P. Mitra,Partha P. Mitra,Pabitra N. Sen,Pabitra N. Sen,Lawrence M. Schwartz,Lawrence M. Schwartz,Pierre Le Doussal,Pierre Le Doussal +7 more
TL;DR: A simple ansatz is proposed that relates the diffusion propagator for the molecules of a fluid confined in a porous medium to the pore-space structure factor and allows for deconvolve structural data from momentum dependent pulsed field gradient spin-echo data.
Journal ArticleDOI
Diffusion MR imaging: clinical applications.
TL;DR: Water self-diffusion, a recently discovered source of contrast on MR images, has already shown promise for some clinical applications and potential applications include diffusion-localized spectroscopy and temperature imaging are suggested.
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