Details

Autor(en) / Beteiligte

• Moutal, Nicolas
• Demberg, Kerstin
• Grebenkov, Denis S.
• Kuder, Tristan Anselm

Titel

Localization regime in diffusion NMR: Theory and experiments

Ist Teil von

• Journal of magnetic resonance (1997), 2019-08, Vol.305, p.162-174

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] •At high b-values, the cumulant expansion diverges and the localization regime emerges.•This regime is investigated both theoretically and experimentally with xenon-129 gas.•We report the signal for diffusion inside slabs/cylinders and outside arrays of rods.•The stretched-exponential decay of the signal is a generic feature at high b-values.•An excellent agreement between theory, numerics and experiments is observed. In this work we investigate the emergence of the localization regime for diffusion NMR in various geometries: inside slabs, inside cylinders and outside rods arranged on a square array. At high gradients, the transverse magnetization is strongly attenuated in the bulk, whereas the macroscopic signal is formed by the remaining magnetization localized near boundaries of the sample. As a consequence, the signal is particularly sensitive to the microstructure. The theoretical analysis relies on recent mathematical advances on the study of the Bloch-Torrey equation. Experiments were conducted with hyperpolarized xenon-129 gas in 3D-printed phantoms and show an excellent agreement with numerical simulations and theoretical predictions. Our mathematical arguments and experimental evidence indicate that the localization regime with a stretched-exponential decay of the macroscopic signal is a generic feature of diffusion NMR that can be observed at moderately high gradients in most NMR scanners.