A new EPI-based dynamic field mapping method: Application to retrospective geometrical distortion corrections
✍ Scribed by Franck Lamberton; Nicolas Delcroix; Denis Grenier; Bernard Mazoyer; Marc Joliot
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 390 KB
- Volume
- 26
- Category
- Article
- ISSN
- 1053-1807
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Purpose
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.
Results
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.
Conclusion
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.