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Voxel spread function method for correction of magnetic field inhomogeneity effects in quantitative
Dmitriy A Yablonskiy1, Alexander L Sukstanskii, Jie Luo
1Department of Radiology, Washington University in St. Louis, St. Louis, Missouri, USA.
Magnetic Resonance in Medicine
|December 13, 2012
Summary
This study introduces a new method to correct magnetic field inhomogeneities in quantitative MRI. The technique improves the accuracy of effective transverse relaxation rate mapping for better tissue property analysis.
Area of Science:
- Medical Imaging
- Biophysics
- Magnetic Resonance Imaging
Background:
- Macroscopic magnetic field inhomogeneities significantly degrade Magnetic Resonance Imaging (MRI) image quality.
- These inhomogeneities introduce bias and corruption in quantitative MRI measurements of biological tissue parameters.
- Accurate quantification of tissue properties is crucial for clinical diagnosis and research.
Purpose of the Study:
- To develop and validate a novel method for correcting macroscopic magnetic field inhomogeneities.
- To enable accurate quantitative measurements in various gradient-echo-based MRI techniques.
- To improve the reliability of MRI-based biological tissue parameter quantification.
Main Methods:
- Reanalyzed gradient echo MRI signal formation theory in the presence of background field inhomogeneities.
- Derived equations for correcting field inhomogeneity effects using phase and magnitude data.
- Verified the theory using computer simulations, phantom studies, and in vivo human data with multi-gradient echo sequences.
Main Results:
- The developed technique effectively corrects for macroscopic magnetic field inhomogeneities.
- Voxel spread function effects were incorporated, yielding artifact-free effective transverse relaxation rate maps.
- Successful correction was demonstrated across simulated, phantom, and in vivo human datasets, excluding areas with extreme field gradients.
Conclusions:
- The voxel spread function method enables accurate quantification of effective transverse relaxation rate-related tissue properties.
- This technique has the potential to generate novel MRI biomarkers for biological tissue properties.
- These biomarkers could serve as valuable surrogates, similar to established relaxation rate constants in MRI.
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