Open AccessConcerning the matching of magnetic susceptibility differences for the compensation of background gradients in anisotropic diffusion fibre phantoms
Author(s) -
Ezequiel Farrher,
Johannes Lindemeyer,
Farida Grinberg,
AnaMaria OrosPeusquens,
N. Jon Shah
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0176192
Subject(s) - anisotropy , materials science , diffusion , nuclear magnetic resonance , relaxation (psychology) , magnetic susceptibility , magnetic field , biological system , biomedical engineering , optics , physics , condensed matter physics , medicine , psychology , social psychology , quantum mechanics , biology , thermodynamics
Artificial, anisotropic fibre phantoms are nowadays increasingly used in the field of diffusion-weighted MRI. Such phantoms represent useful tools for, among others, the calibration of pulse sequences and validation of diffusion models since they can mimic well-known structural features of brain tissue on the one hand, but exhibit a reduced complexity, on the other. Among all materials, polyethylene fibres have been widely used due to their excellent properties regarding the restriction of water diffusion and surface relaxation properties. Yet the magnetic susceptibility of polyethylene can be distinctly lower than that of distilled water. This difference produces strong microscopic, background field gradients in the vicinity of fibre bundles which are not parallel to the static magnetic field. This, in turn, modulates the MRI signal behaviour. In the present work we investigate an approach to reduce the susceptibility-induced background gradients via reducing the heterogeneity in the internal magnetic susceptibility. An aqueous solution of magnesium chloride hexahydrate (MgCl 2 ·6H 2 O) is used for this purpose. Its performance is demonstrated in dedicated anisotropic fibre phantoms with different geometrical configurations.