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NMR diffusion-encoding with axial symmetry and variable anisotropy: Distinguishing between prolate and oblate microscopic diffusion tensors with unknown orientation distribution.

ERIKSSON, STEFANIE LU ; Lasič, Samo; Nilsson, Markus LU ; Westin, Carl-Fredrik and Topgaard, Daniel LU (2015) In Journal of Chemical Physics 142(10).
Abstract
We introduce a nuclear magnetic resonance method for quantifying the shape of axially symmetric microscopic diffusion tensors in terms of a new diffusion anisotropy metric, DΔ, which has unique values for oblate, spherical, and prolate tensor shapes. The pulse sequence includes a series of equal-amplitude magnetic field gradient pulse pairs, the directions of which are tailored to give an axially symmetric diffusion-encoding tensor b with variable anisotropy bΔ. Averaging of data acquired for a range of orientations of the symmetry axis of the tensor b renders the method insensitive to the orientation distribution function of the microscopic diffusion tensors. Proof-of-principle experiments are performed on water in polydomain lyotropic... (More)
We introduce a nuclear magnetic resonance method for quantifying the shape of axially symmetric microscopic diffusion tensors in terms of a new diffusion anisotropy metric, DΔ, which has unique values for oblate, spherical, and prolate tensor shapes. The pulse sequence includes a series of equal-amplitude magnetic field gradient pulse pairs, the directions of which are tailored to give an axially symmetric diffusion-encoding tensor b with variable anisotropy bΔ. Averaging of data acquired for a range of orientations of the symmetry axis of the tensor b renders the method insensitive to the orientation distribution function of the microscopic diffusion tensors. Proof-of-principle experiments are performed on water in polydomain lyotropic liquid crystals with geometries that give rise to microscopic diffusion tensors with oblate, spherical, and prolate shapes. The method could be useful for characterizing the geometry of fluid-filled compartments in porous solids, soft matter, and biological tissues. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Chemical Physics
volume
142
issue
10
publisher
American Institute of Physics
external identifiers
  • pmid:25770532
  • wos:000350978000046
  • scopus:84924371181
ISSN
0021-9606
DOI
10.1063/1.4913502
language
English
LU publication?
yes
id
d9ebfa6d-fe17-4197-9ad0-97d808ce1ba1 (old id 5258653)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/25770532?dopt=Abstract
date added to LUP
2015-04-03 19:06:22
date last changed
2017-11-05 03:18:57
@article{d9ebfa6d-fe17-4197-9ad0-97d808ce1ba1,
  abstract     = {We introduce a nuclear magnetic resonance method for quantifying the shape of axially symmetric microscopic diffusion tensors in terms of a new diffusion anisotropy metric, DΔ, which has unique values for oblate, spherical, and prolate tensor shapes. The pulse sequence includes a series of equal-amplitude magnetic field gradient pulse pairs, the directions of which are tailored to give an axially symmetric diffusion-encoding tensor b with variable anisotropy bΔ. Averaging of data acquired for a range of orientations of the symmetry axis of the tensor b renders the method insensitive to the orientation distribution function of the microscopic diffusion tensors. Proof-of-principle experiments are performed on water in polydomain lyotropic liquid crystals with geometries that give rise to microscopic diffusion tensors with oblate, spherical, and prolate shapes. The method could be useful for characterizing the geometry of fluid-filled compartments in porous solids, soft matter, and biological tissues.},
  articleno    = {104201},
  author       = {ERIKSSON, STEFANIE and Lasič, Samo and Nilsson, Markus and Westin, Carl-Fredrik and Topgaard, Daniel},
  issn         = {0021-9606},
  language     = {eng},
  number       = {10},
  publisher    = {American Institute of Physics},
  series       = {Journal of Chemical Physics},
  title        = {NMR diffusion-encoding with axial symmetry and variable anisotropy: Distinguishing between prolate and oblate microscopic diffusion tensors with unknown orientation distribution.},
  url          = {http://dx.doi.org/10.1063/1.4913502},
  volume       = {142},
  year         = {2015},
}