## Abstract ## Purpose To examine the usefulness of variable‐density k‐space trajectories for the design of multi‐dimensional spatially selective RF pulses. ## Materials and Methods Experimental phantom and in vivo studies were performed and confirmed by simulations. Two‐dimensional spatially se
Retrospective motion compensation using variable-density spiral trajectories
✍ Scribed by General Leung; Donald B. Plewes
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 595 KB
- Volume
- 22
- Category
- Article
- ISSN
- 1053-1807
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Purpose
To develop a method of retrospectively correcting for motion artifacts using a variable‐density spiral (VDS) trajectory.
Materials and Methods
Each VDS interleaf was designed to adequately sample the same center region of k‐space. This central overlapping region can then be used to measure rigid body motion between the acquisition of each VDS interleaf. By applying appropriate phase shifts and rotations of the k‐space data, rigid body motion artifacts can be removed, resulting in images with less motion corruption.
Results
Both phantom and volunteer experiments are shown, demonstrating the technique's ability to further reduce artifacts in images acquired with an already motion‐resistant acquisition trajectory. Registration accuracy is highly dependent on the trajectory design parameters. This space was explored to find an optimal design of VDS trajectories for motion compensation.
Conclusion
Using appropriately designed VDS trajectories, residual motion artifacts can be significantly reduced by retrospectively correcting for in‐plane rigid body motion. An overlapping region of approximately 8% of the central region of k‐space and approximately 70 interleaves were found to be near‐optimal parameters for retrospective correction using VDS trajectories. J. Magn. Reson. Imaging 2005. © 2005 Wiley‐Liss, Inc.
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