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FID modulus: a simple and efficient technique to phase and align MR spectra
Yann Le Fur1, Patrick J Cozzone
1Aix-Marseille Université, CNRS, CRMBM UMR 7339, 13385, Marseille, France, yann.le-fur@univ-amu.fr.
Magma (New York, N.Y.)
|June 25, 2013
Summary
This study presents a simple method to automatically phase correct and frequency align MR spectra by using the modulus of the free induction decay (FID) signal. This technique is efficient for processing large datasets, particularly in brain proton MR spectroscopy.
Area of Science:
- Magnetic Resonance Imaging
- Spectroscopy
- Signal Processing
Background:
- Automating post-processing of MR spectroscopic data, including phase correction and chemical shift assignment, is crucial for large-scale analyses.
- Manual phase correction and frequency assignment are time-consuming and impractical for large datasets or complex acquisitions like phased array coils.
Purpose of the Study:
- To develop an automated method for phase correction and frequency alignment of MR spectra.
- To address the challenges of processing large MR spectroscopic datasets efficiently.
Main Methods:
- The proposed method utilizes the modulus of the free induction decay (FID) signal to correct for zero-order phase variations.
- Frequency shifts are addressed by analyzing the first-order phase variations within the FID signal.
Main Results:
- Calculating the modulus of the FID signal effectively corrects phase and aligns spectra automatically under specific conditions.
- This technique is applicable to combining signals from phased array coils, phase-coherent averaging, and B0 shift correction.
Conclusions:
- Working with the modulus of the FID signal offers a simple and efficient automated solution for MR spectral phase correction and frequency alignment.
- The method is particularly well-suited for proton MR spectroscopy of the brain.
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