A new EPI-based dynamic field mapping method: Application to retrospective geometrical distortion corrections
Article first published online: 29 AUG 2007
Copyright © 2007 Wiley-Liss, Inc.
Journal of Magnetic Resonance Imaging
Volume 26, Issue 3, pages 747–755, September 2007
How to Cite
Lamberton, F., Delcroix, N., Grenier, D., Mazoyer, B. and Joliot, M. (2007), A new EPI-based dynamic field mapping method: Application to retrospective geometrical distortion corrections. J. Magn. Reson. Imaging, 26: 747–755. doi: 10.1002/jmri.21039
- Issue published online: 29 AUG 2007
- Article first published online: 29 AUG 2007
- Manuscript Accepted: 1 MAY 2007
- Manuscript Received: 27 JUN 2006
- dynamic field mapping;
- distortion correction;
- phase image;
- retrospective correction
To retrospectively correct for geometrical distortions, a new dynamic field mapping method suitable for dynamic single-shot gradient-echo type echo-planar imaging (GRE-EPI) is proposed.
Materials and Methods
The method requires a single volume additional acquisition and allows the extraction of a field map from each phase volume, assuming invariance across time of the echo time-independent phase component. Performances of the method are assessed using three sets of experiments: the first tests the prerequisite and the modeling; the second tests the method with time-dependent geometrical distortions; and the third presents a comparison with two other methods.
Our results legitimize the modeling procedure and demonstrate that the dynamic method is less sensitive to noise than the other methods. A theoretical explanation for this is proposed in the discussion section.
Given the minor increase in the acquisition time, this method is well suited for functional magnetic resonance imaging; prospective direction. J. Magn. Reson. Imaging 2007;26:747–755. © 2007 Wiley-Liss, Inc.