TY  - JOUR
A1  - Moutal, Nicolas
A1  - Grebenkov, Denis S.
T1  - The localization regime in a nutshell
JF  - Journal of magnetic resonance : JMR
N2  - High diffusion-sensitizing magnetic field gradients have been more and more often applied nowadays to achieve a better characterization of the microstructure. As the resulting spin-echo signal significantly deviates from the conventional Gaussian form, various models have been employed to interpret these deviations and to relate them with the microstructural properties of a sample. In this paper, we argue that the non-Gaussian behavior of the signal is a generic universal feature of the Bloch-Torrey equation. We provide a simple yet rigorous description of the localization regime emerging at high extended gradients and identify its origin as a symmetry breaking at the reflecting boundary. We compare the consequent non-Gaussian signal decay to other diffusion NMR regimes such as slow-diffusion, motional-narrowing and diffusion-diffraction regimes. We emphasize limitations of conventional perturbative techniques and advocate for non-perturbative approaches which may pave a way to new imaging modalities in this field.
KW  - Localization regime
KW  - Bloch-Torrey equation
KW  - Diffusion NMR
KW  - Spin-echo
KW  - Non-perturbative analysis
Y1  - 2020
U6  - https://doi.org/10.1016/j.jmr.2020.106836
SN  - 1090-7807
SN  - 1096-0856
VL  - 320
PB  - Elsevier
CY  - San Diego, Calif. [u.a.]
ER  -