Advanced

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

Wirestam, Ronnie LU ; 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)
Please use this url to cite or link to this publication:
author
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
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
2008-07-30 10:11:16
date last changed
2017-02-05 03:45:12
@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},
  keyword      = {Magnetic resonance,MR imaging,Diffusion,Brain motion,Phase dispersion,Perfusion},
  language     = {eng},
  number       = {2},
  pages        = {348--355},
  publisher    = {John Wiley & Sons},
  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},
  volume       = {6},
  year         = {1996},
}