## Abstract Many MR‐guided interventional procedures rely on fast imaging sequences for providing images in real‐time with a precise relation between the target position in the image and its true position. Echo‐planar imaging (EPI) methods are very fast but prone to geometric distortions. Here, we
Correction for EPI distortions using multi-echo gradient-echo imaging
✍ Scribed by Nan-kuei Chen; Alice M. Wyrwicz
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 285 KB
- Volume
- 41
- Category
- Article
- ISSN
- 0740-3194
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✦ Synopsis
A novel and effective technique is described for distortion correction in echo planar imaging (EPI) utilizing the field maps derived from multi-echo gradient-echo images. The distortions from different off-resonance related factors such as field inhomogeneity, eddy current effect, radiofrequency pulse frequency offset, and chemical shift effect can be simultaneously reduced to a great extent. With the proposed post-processing algorithm of multi-channel modulation, distortions may be corrected without unwrapping the phase discontinuities in the derived field map, a process that usually restricts the application of other field map-based correction methods. Results from phantom and animal experiments at 4.7 T demonstrate the efficiency of the method in reducing the geometrical distortions in gradient-echo
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