Abstract
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 EPI.
Original language | English (US) |
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Pages (from-to) | 1206-1213 |
Number of pages | 8 |
Journal | Magnetic Resonance in Medicine |
Volume | 41 |
Issue number | 6 |
DOIs | |
State | Published - 1999 |
Externally published | Yes |
Keywords
- Echo planar imaging (EPI)
- Field mapping
- Geometrical distortions
- Multi-channel modulation
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging