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B1 homogenization in MRI by multilayer coupled coils.
Shumin Wang1, Joseph Murphy-Boesch, Hellmut Merkle
1Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892 USA. wangshu@ninds.nih.gov
IEEE Transactions on Medical Imaging
|April 2, 2009
Summary
Achieving uniform B(1)(+) fields in high-field ( > 3.0 T) human magnetic resonance imaging (MRI) is difficult. Coupling surface coils to a volume coil effectively homogenizes these fields for 7.0 T proton MRI of the human head.
Area of Science:
- Magnetic Resonance Imaging
- Biophysics
- Electromagnetism
Background:
- High-field magnetic resonance imaging (MRI) (> 3.0 T) faces challenges in B(1)(+) field transmission and homogeneity.
- Radio-frequency wavelength effects impede uniform B(1)(+) field distribution in high-field MRI.
Purpose of the Study:
- To investigate an approach for improving B(1)(+) field homogenization in high-field human MRI.
- To assess the feasibility and effectiveness of coupling surface coils to a volume coil for enhanced field uniformity.
Main Methods:
- Electromagnetic simulations were employed to model the behavior of coupled surface and volume coils.
- The proposed method was specifically evaluated for proton magnetic resonance imaging of the human head at 7.0 T.
Main Results:
- Electromagnetic simulations demonstrated that coupling surface coils to a volume coil is a feasible approach.
- The method proved effective in achieving B(1)(+) field homogenization at 7.0 T.
Conclusions:
- Coupling surface coils to a volume coil is a viable strategy for B(1)(+) field homogenization in high-field MRI.
- This technique enhances field uniformity, crucial for high-quality proton MRI of the human head at 7.0 T.
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