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Tracking of rigid head motion during MRI using an EEG system

Laustsen, Malte ; Andersen, Mads LU ; Xue, Rong ; Madsen, Kristoffer H. and Hanson, Lars G. (2022) In Magnetic Resonance in Medicine 82(2). p.986-1001
Abstract

Purpose: To demonstrate a novel method for tracking of head movements during MRI using electroencephalography (EEG) hardware for recording signals induced by native imaging gradients. Theory and Methods: Gradient switching during simultaneous EEG–fMRI induces distortions in EEG signals, which depend on subject head position and orientation. When EEG electrodes are interconnected with high-impedance carbon wire loops, the induced voltages are linear combinations of the temporal gradient waveform derivatives. We introduce head tracking based on these signals (CapTrack) involving 3 steps: (1) phantom scanning is used to characterize the target sequence and a fast calibration sequence; (2) a linear relation between changes of induced... (More)

Purpose: To demonstrate a novel method for tracking of head movements during MRI using electroencephalography (EEG) hardware for recording signals induced by native imaging gradients. Theory and Methods: Gradient switching during simultaneous EEG–fMRI induces distortions in EEG signals, which depend on subject head position and orientation. When EEG electrodes are interconnected with high-impedance carbon wire loops, the induced voltages are linear combinations of the temporal gradient waveform derivatives. We introduce head tracking based on these signals (CapTrack) involving 3 steps: (1) phantom scanning is used to characterize the target sequence and a fast calibration sequence; (2) a linear relation between changes of induced signals and head pose is established using the calibration sequence; and (3) induced signals recorded during target sequence scanning are used for tracking and retrospective correction of head movement without prolonging the scan time of the target sequence. Performance of CapTrack is compared directly to interleaved navigators. Results: Head-pose tracking at 27.5 Hz during echo planar imaging (EPI) was demonstrated with close resemblance to rigid body alignment (mean absolute difference: [0.14 0.38 0.15]-mm translation, [0.30 0.27 0.22]-degree rotation). Retrospective correction of 3D gradient-echo imaging shows an increase of average edge strength of 12%/−0.39% for instructed/uninstructed motion with CapTrack pose estimates, with a tracking interval of 1561 ms and high similarity to interleaved navigator estimates (mean absolute difference: [0.13 0.33 0.12] mm, [0.28 0.15 0.22] degrees). Conclusion: Motion can be estimated from recordings of gradient switching with little or no sequence modification, optionally in real time at low computational burden and synchronized to image acquisition, using EEG equipment already found at many research institutions.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
artifact correction, brain MRI, EEG system, motion tracking method, prospective motion correction
in
Magnetic Resonance in Medicine
volume
82
issue
2
pages
986 - 1001
publisher
John Wiley & Sons Inc.
external identifiers
  • scopus:85128774349
  • pmid:35468237
ISSN
0740-3194
DOI
10.1002/mrm.29251
language
English
LU publication?
yes
id
3559bdaf-9f0b-452b-a052-7b280c578123
date added to LUP
2022-07-01 13:23:00
date last changed
2024-06-14 20:37:24
@article{3559bdaf-9f0b-452b-a052-7b280c578123,
  abstract     = {{<p>Purpose: To demonstrate a novel method for tracking of head movements during MRI using electroencephalography (EEG) hardware for recording signals induced by native imaging gradients. Theory and Methods: Gradient switching during simultaneous EEG–fMRI induces distortions in EEG signals, which depend on subject head position and orientation. When EEG electrodes are interconnected with high-impedance carbon wire loops, the induced voltages are linear combinations of the temporal gradient waveform derivatives. We introduce head tracking based on these signals (CapTrack) involving 3 steps: (1) phantom scanning is used to characterize the target sequence and a fast calibration sequence; (2) a linear relation between changes of induced signals and head pose is established using the calibration sequence; and (3) induced signals recorded during target sequence scanning are used for tracking and retrospective correction of head movement without prolonging the scan time of the target sequence. Performance of CapTrack is compared directly to interleaved navigators. Results: Head-pose tracking at 27.5 Hz during echo planar imaging (EPI) was demonstrated with close resemblance to rigid body alignment (mean absolute difference: [0.14 0.38 0.15]-mm translation, [0.30 0.27 0.22]-degree rotation). Retrospective correction of 3D gradient-echo imaging shows an increase of average edge strength of 12%/−0.39% for instructed/uninstructed motion with CapTrack pose estimates, with a tracking interval of 1561 ms and high similarity to interleaved navigator estimates (mean absolute difference: [0.13 0.33 0.12] mm, [0.28 0.15 0.22] degrees). Conclusion: Motion can be estimated from recordings of gradient switching with little or no sequence modification, optionally in real time at low computational burden and synchronized to image acquisition, using EEG equipment already found at many research institutions.</p>}},
  author       = {{Laustsen, Malte and Andersen, Mads and Xue, Rong and Madsen, Kristoffer H. and Hanson, Lars G.}},
  issn         = {{0740-3194}},
  keywords     = {{artifact correction; brain MRI; EEG system; motion tracking method; prospective motion correction}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{986--1001}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Magnetic Resonance in Medicine}},
  title        = {{Tracking of rigid head motion during MRI using an EEG system}},
  url          = {{http://dx.doi.org/10.1002/mrm.29251}},
  doi          = {{10.1002/mrm.29251}},
  volume       = {{82}},
  year         = {{2022}},
}