Journal article
A general algorithm for compensation of trajectory errors: Application to radial imaging
Magnetic resonance in medicine, Vol.80(4), pp.1605-1613
10/2018
DOI: 10.1002/mrm.27148
PMCID: PMC8526284
PMID: 29493002
Abstract
Purpose
To reconstruct artifact‐free images from measured k‐space data, when the actual k‐space trajectory deviates from the nominal trajectory due to gradient imperfections.
Methods
Trajectory errors arising from eddy currents and gradient delays introduce phase inconsistencies in several fast scanning MR pulse sequences, resulting in image artifacts. The proposed algorithm provides a novel framework to compensate for this phase distortion. The algorithm relies on the construction of a multi‐block Hankel matrix, where each block is constructed from k‐space segments with the same phase distortion. In the presence of spatially smooth phase distortions between the segments, the complete block‐Hankel matrix is known to be highly low‐rank. Since each k‐space segment is only acquiring part of the k‐space data, the reconstruction of the phase compensated image from their partially parallel measurements is posed as a structured low‐rank matrix optimization problem, assuming the coil sensitivities to be known.
Results
The proposed formulation is tested on radial acquisitions in several settings including partial Fourier and golden‐angle acquisitions. The experiments demonstrate the ability of the algorithm to successfully remove the artifacts arising from the trajectory errors, without the need for trajectory or phase calibration. The quality of the reconstruction was comparable to corrections achieved using the Trajectory Auto‐Corrected Image Reconstruction (TrACR) for radial acquisitions.
Conclusion
The proposed method provides a general framework for the recovery of artifact‐free images from radial trajectories without the need for trajectory calibration.
Details
- Title: Subtitle
- A general algorithm for compensation of trajectory errors: Application to radial imaging
- Creators
- Merry Mani - University of IowaVincent Magnotta - University of IowaMathews Jacob - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Magnetic resonance in medicine, Vol.80(4), pp.1605-1613
- DOI
- 10.1002/mrm.27148
- PMID
- 29493002
- PMCID
- PMC8526284
- NLM abbreviation
- Magn Reson Med
- ISSN
- 0740-3194
- eISSN
- 1522-2594
- Number of pages
- 9
- Grant note
- National Institute of Biomedical Imaging and Bioengineering (NIH 1R01EB019961‐01A1 ; NIH 1R01EB022019‐01A1)
- Language
- English
- Date published
- 10/2018
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Electrical and Computer Engineering; Psychiatry; Iowa Neuroscience Institute; Radiation Oncology
- Record Identifier
- 9984051572802771
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