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Constrained optimization of gradient waveforms for generalized diffusion encoding.

Sjölund, Jens; Szczepankiewicz, Filip LU ; Nilsson, Markus LU ; Topgaard, Daniel; Westin, Carl-Fredrik and Knutsson, Hans (2015) In Journal of Magnetic Resonance 261. p.157-168
Abstract
Diffusion MRI is a useful probe of tissue microstructure. The conventional diffusion encoding sequence, the single pulsed field gradient, has recently been challenged as more general gradient waveforms have been introduced. Out of these, we focus on q-space trajectory imaging, which generalizes the scalar b-value to a tensor valued entity. To take full advantage of its capabilities, it is imperative to respect the constraints imposed by the hardware, while at the same time maximizing the diffusion encoding strength. We provide a tool that achieves this by solving a constrained optimization problem that accommodates constraints on maximum gradient amplitude, slew rate, coil heating and positioning of radio frequency pulses. The method's... (More)
Diffusion MRI is a useful probe of tissue microstructure. The conventional diffusion encoding sequence, the single pulsed field gradient, has recently been challenged as more general gradient waveforms have been introduced. Out of these, we focus on q-space trajectory imaging, which generalizes the scalar b-value to a tensor valued entity. To take full advantage of its capabilities, it is imperative to respect the constraints imposed by the hardware, while at the same time maximizing the diffusion encoding strength. We provide a tool that achieves this by solving a constrained optimization problem that accommodates constraints on maximum gradient amplitude, slew rate, coil heating and positioning of radio frequency pulses. The method's efficacy and flexibility is demonstrated both experimentally and by comparison with previous work on optimization of isotropic diffusion sequences. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Magnetic Resonance
volume
261
pages
157 - 168
publisher
Elsevier
external identifiers
  • pmid:26583528
  • wos:000367212100021
  • scopus:84946846891
ISSN
1096-0856
DOI
10.1016/j.jmr.2015.10.012
language
English
LU publication?
yes
id
6ac5317f-3885-4521-8400-3ab3632b34f1 (old id 8235157)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/26583528?dopt=Abstract
date added to LUP
2015-12-05 19:11:55
date last changed
2017-11-05 03:18:54
@article{6ac5317f-3885-4521-8400-3ab3632b34f1,
  abstract     = {Diffusion MRI is a useful probe of tissue microstructure. The conventional diffusion encoding sequence, the single pulsed field gradient, has recently been challenged as more general gradient waveforms have been introduced. Out of these, we focus on q-space trajectory imaging, which generalizes the scalar b-value to a tensor valued entity. To take full advantage of its capabilities, it is imperative to respect the constraints imposed by the hardware, while at the same time maximizing the diffusion encoding strength. We provide a tool that achieves this by solving a constrained optimization problem that accommodates constraints on maximum gradient amplitude, slew rate, coil heating and positioning of radio frequency pulses. The method's efficacy and flexibility is demonstrated both experimentally and by comparison with previous work on optimization of isotropic diffusion sequences.},
  author       = {Sjölund, Jens and Szczepankiewicz, Filip and Nilsson, Markus and Topgaard, Daniel and Westin, Carl-Fredrik and Knutsson, Hans},
  issn         = {1096-0856},
  language     = {eng},
  pages        = {157--168},
  publisher    = {Elsevier},
  series       = {Journal of Magnetic Resonance},
  title        = {Constrained optimization of gradient waveforms for generalized diffusion encoding.},
  url          = {http://dx.doi.org/10.1016/j.jmr.2015.10.012},
  volume       = {261},
  year         = {2015},
}