Related Experiment Video
Updated: May 26, 2026
Sample Drift Correction Following 4D Confocal Time-lapse Imaging
Published on: April 12, 2014
Model for the correction of motion-induced phase errors in multishot diffusion-weighted-MRI of the head: are
R L O'Halloran1, S Holdsworth, M Aksoy
1Department of Radiology, Stanford University, Stanford, California, USA. rafaelo@stanford.edu
Abstract:
In diffusion-weighted imaging, multishot acquisitions are problematic due to intershot inconsistencies of the phase caused by motion during the diffusion-encoding gradients. A model for the motion-induced phase errors in diffusion-weighted-MRI of the brain is presented, in which rigid-body and nonrigid-body motion are separated. In the model, it is assumed that nonrigid-body motion is due to cardiac pulsation, and that the motion patterns are repeatable from beat-to-beat. To test the validity of this assumption, the repeatability of nonrigid-body motion-induced phase errors is quantified in three healthy volunteers. Nonrigid-body motion-induced phase was found to significantly correlate (P < 0.05) with pulse-oximeter waveforms in ~83% of the pixels tested across all slices and subjects.
Insights
Motion during diffusion-weighted imaging causes phase errors. This study models these errors, separating rigid and non-rigid motion, and finds non-rigid motion correlates with pulse waveforms, suggesting repeatable patterns for improved MRI.
Area of Science:
- Medical Imaging
- Biophysics
- Neuroimaging
Background:
- Multishot diffusion-weighted imaging (DWI) is susceptible to intershot phase inconsistencies.
- These inconsistencies arise from motion during diffusion-encoding gradients, complicating image analysis.
- Accurate modeling of motion-induced phase errors is crucial for robust DWI.
Purpose of the Study:
- To present a model separating rigid-body and nonrigid-body motion-induced phase errors in brain DWI.
- To investigate the repeatability of nonrigid-body motion-induced phase errors, assuming cardiac pulsation as the source.
- To validate the assumption of repeatable nonrigid-body motion patterns in healthy volunteers.
Main Methods:
- Developed a model to differentiate rigid and nonrigid motion effects on phase errors in DWI.
- Assessed the repeatability of nonrigid motion-induced phase errors by comparing beat-to-beat variations.
- Quantified phase error repeatability in three healthy volunteers using pulse-oximeter waveforms.
Main Results:
- The developed model successfully separated rigid and nonrigid motion components.
- Nonrigid-body motion-induced phase errors demonstrated significant repeatability across subjects and slices.
- An ~83% correlation was found between nonrigid-body motion-induced phase and pulse-oximeter waveforms (P < 0.05).
Conclusions:
- Nonrigid-body motion in DWI is largely attributable to cardiac pulsation and exhibits repeatable patterns.
- The findings support the assumption of repeatable beat-to-beat motion for modeling phase errors.
- This research contributes to improving the accuracy and reliability of diffusion-weighted MRI.
