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Theoretical and experimental evaluation of phase-dispersion effects caused by brain motion in diffusion and perfusion MR imaging

Wirestam, Ronnie LU orcid ; Greitz, Dan ; Thomsen, Carsten ; Brockstedt, Sara LU ; Olsson, Magnus B. E. and Ståhlberg, Freddy LU (1996) In Journal of Magnetic Resonance Imaging 6(2). p.348-355
Abstract
We investigated intravoxel phase dispersion caused by pulsatile brain motion in diffusion spin-echo pulse sequences. Mathematical models were used to describe the spatial and temporal velocity distributions of human brain motion. The spatial distribution of brain-tissue velocity introduces a phase spread over one voxel, leading to signal loss. This signal loss was estimated theoretically, and effects on observed diffusion coefficient and perfused capillary fraction were assessed. When parameters from a diffusion pulse sequence without motion compensation were used, and ECG triggering with inappropriate delay times was assumed, the maximal signal loss caused by brain-motion-induced phase dispersion was predicted to be 21%. This corresponds... (More)
We investigated intravoxel phase dispersion caused by pulsatile brain motion in diffusion spin-echo pulse sequences. Mathematical models were used to describe the spatial and temporal velocity distributions of human brain motion. The spatial distribution of brain-tissue velocity introduces a phase spread over one voxel, leading to signal loss. This signal loss was estimated theoretically, and effects on observed diffusion coefficient and perfused capillary fraction were assessed. When parameters from a diffusion pulse sequence without motion compensation were used, and ECG triggering with inappropriate delay times was assumed, the maximal signal loss caused by brain-motion-induced phase dispersion was predicted to be 21%. This corresponds to a 95% overestimation of the diffusion coefficient, and the perfusion-fraction error was small. Corresponding calculations for motion-compensated pulse sequences predicted a 1% to 1.5% signal loss due to undesired phase dispersion, whereas experimental results indicated a signal loss related to brain motion of 4%. (Less)
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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Magnetic resonance, MR imaging, Diffusion, Brain motion, Phase dispersion, Perfusion
in
Journal of Magnetic Resonance Imaging
volume
6
issue
2
pages
348 - 355
publisher
John Wiley & Sons Inc.
external identifiers
  • pmid:9132101
  • scopus:0030090119
ISSN
1522-2586
DOI
10.1002/jmri.1880060215
language
English
LU publication?
yes
id
3e4f65e8-910d-4480-9abf-2ecfd6452915 (old id 1109922)
date added to LUP
2016-04-01 12:34:30
date last changed
2022-01-27 06:55:16
@article{3e4f65e8-910d-4480-9abf-2ecfd6452915,
  abstract     = {{We investigated intravoxel phase dispersion caused by pulsatile brain motion in diffusion spin-echo pulse sequences. Mathematical models were used to describe the spatial and temporal velocity distributions of human brain motion. The spatial distribution of brain-tissue velocity introduces a phase spread over one voxel, leading to signal loss. This signal loss was estimated theoretically, and effects on observed diffusion coefficient and perfused capillary fraction were assessed. When parameters from a diffusion pulse sequence without motion compensation were used, and ECG triggering with inappropriate delay times was assumed, the maximal signal loss caused by brain-motion-induced phase dispersion was predicted to be 21%. This corresponds to a 95% overestimation of the diffusion coefficient, and the perfusion-fraction error was small. Corresponding calculations for motion-compensated pulse sequences predicted a 1% to 1.5% signal loss due to undesired phase dispersion, whereas experimental results indicated a signal loss related to brain motion of 4%.}},
  author       = {{Wirestam, Ronnie and Greitz, Dan and Thomsen, Carsten and Brockstedt, Sara and Olsson, Magnus B. E. and Ståhlberg, Freddy}},
  issn         = {{1522-2586}},
  keywords     = {{Magnetic resonance; MR imaging; Diffusion; Brain motion; Phase dispersion; Perfusion}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{348--355}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Journal of Magnetic Resonance Imaging}},
  title        = {{Theoretical and experimental evaluation of phase-dispersion effects caused by brain motion in diffusion and perfusion MR imaging}},
  url          = {{http://dx.doi.org/10.1002/jmri.1880060215}},
  doi          = {{10.1002/jmri.1880060215}},
  volume       = {{6}},
  year         = {{1996}},
}