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Liquid crystal phantom for validation of microscopic diffusion anisotropy measurements on clinical MRI systems.

Nilsson, Markus LU ; Larsson, Johan LU ; Lundberg, Dan; Szczepankiewicz, Filip LU ; Witzel, Thomas; Westin, Carl-Fredrik; Bryskhe, Karin and Topgaard, Daniel LU (2018) In Magnetic Resonance in Medicine 79(3). p.1817-1828
Abstract
PURPOSE:
To develop a phantom for validating MRI pulse sequences and data processing methods to quantify microscopic diffusion anisotropy in the human brain.

METHODS:
Using a liquid crystal consisting of water, detergent, and hydrocarbon, we designed a 0.5-L spherical phantom showing the theoretically highest possible degree of microscopic anisotropy. Data were acquired on the Connectome scanner using echo-planar imaging signal readout and diffusion encoding with axisymmetric b-tensors of varying magnitude, anisotropy, and orientation. The mean diffusivity, fractional anisotropy (FA), and microscopic FA (µFA) parameters were estimated.

RESULTS:
The phantom was observed to have values of mean diffusivity... (More)
PURPOSE:
To develop a phantom for validating MRI pulse sequences and data processing methods to quantify microscopic diffusion anisotropy in the human brain.

METHODS:
Using a liquid crystal consisting of water, detergent, and hydrocarbon, we designed a 0.5-L spherical phantom showing the theoretically highest possible degree of microscopic anisotropy. Data were acquired on the Connectome scanner using echo-planar imaging signal readout and diffusion encoding with axisymmetric b-tensors of varying magnitude, anisotropy, and orientation. The mean diffusivity, fractional anisotropy (FA), and microscopic FA (µFA) parameters were estimated.

RESULTS:
The phantom was observed to have values of mean diffusivity similar to brain tissue, and relaxation times compatible with echo-planar imaging echo times on the order of 100 ms. The estimated values of µFA were at the theoretical maximum of 1.0, whereas the values of FA spanned the interval from 0.0 to 0.8 as a result of varying orientational order of the anisotropic domains within each voxel.

CONCLUSIONS:
The proposed phantom can be manufactured by mixing three widely available chemicals in volumes comparable to a human head. The acquired data are in excellent agreement with theoretical predictions, showing that the phantom is ideal for validating methods for measuring microscopic diffusion anisotropy on clinical MRI systems. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Magnetic Resonance in Medicine
volume
79
issue
3
pages
1817 - 1828
publisher
Wiley Online Library
external identifiers
  • scopus:85021957740
ISSN
1522-2594
DOI
10.1002/mrm.26814
language
English
LU publication?
yes
id
48ad583e-90e6-4f53-8b03-9602f3506c9f
date added to LUP
2019-05-22 17:00:14
date last changed
2019-07-21 05:17:08
@article{48ad583e-90e6-4f53-8b03-9602f3506c9f,
  abstract     = {PURPOSE:<br/>To develop a phantom for validating MRI pulse sequences and data processing methods to quantify microscopic diffusion anisotropy in the human brain.<br/><br/>METHODS:<br/>Using a liquid crystal consisting of water, detergent, and hydrocarbon, we designed a 0.5-L spherical phantom showing the theoretically highest possible degree of microscopic anisotropy. Data were acquired on the Connectome scanner using echo-planar imaging signal readout and diffusion encoding with axisymmetric b-tensors of varying magnitude, anisotropy, and orientation. The mean diffusivity, fractional anisotropy (FA), and microscopic FA (µFA) parameters were estimated.<br/><br/>RESULTS:<br/>The phantom was observed to have values of mean diffusivity similar to brain tissue, and relaxation times compatible with echo-planar imaging echo times on the order of 100 ms. The estimated values of µFA were at the theoretical maximum of 1.0, whereas the values of FA spanned the interval from 0.0 to 0.8 as a result of varying orientational order of the anisotropic domains within each voxel.<br/><br/>CONCLUSIONS:<br/>The proposed phantom can be manufactured by mixing three widely available chemicals in volumes comparable to a human head. The acquired data are in excellent agreement with theoretical predictions, showing that the phantom is ideal for validating methods for measuring microscopic diffusion anisotropy on clinical MRI systems.},
  author       = {Nilsson, Markus and Larsson, Johan and Lundberg, Dan and Szczepankiewicz, Filip and Witzel, Thomas and Westin, Carl-Fredrik and Bryskhe, Karin and Topgaard, Daniel},
  issn         = {1522-2594},
  language     = {eng},
  number       = {3},
  pages        = {1817--1828},
  publisher    = {Wiley Online Library},
  series       = {Magnetic Resonance in Medicine},
  title        = {Liquid crystal phantom for validation of microscopic diffusion anisotropy measurements on clinical MRI systems.},
  url          = {http://dx.doi.org/10.1002/mrm.26814},
  volume       = {79},
  year         = {2018},
}