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Transmit gain calibration for nonproton MR using the Bloch-Siegert shift
Rolf F Schulte1, Laura Sacolick, Martin H Deppe
1GE Global Research, Munich, Germany. Rolf.Schulte@research.ge.com
NMR in Biomedicine
|March 10, 2011
Summary
This study introduces a new method for calibrating radiofrequency (RF) power in magnetic resonance imaging (MRI) using the Bloch-Siegert shift. This technique simplifies calibration for non-proton MRI, including hyperpolarized applications.
Area of Science:
- Magnetic Resonance Imaging (MRI)
- Radiofrequency (RF) Physics
- Hyperpolarized Contrast Agents
Background:
- Transmit gain (B1+) calibration is crucial for accurate RF power adjustment in MRI.
- Proton MRI calibration is automated, but challenging for other nuclei, especially hyperpolarized ones.
Purpose of the Study:
- To develop and validate a novel transmit gain calibration method for MRI.
- To enable efficient calibration for non-proton and hyperpolarized MRI applications.
Main Methods:
- Implemented transmit gain calibration based on the Bloch-Siegert phase shift.
- Utilized the same data to determine center frequency, line broadening, and SNR.
Main Results:
- The Bloch-Siegert shift-based method provides accurate B1+ calibration.
- The technique is insensitive to T1 and B0 variations.
- Effective over a wide range of B1+ values.
Conclusions:
- The Bloch-Siegert shift method offers a robust and efficient solution for B1+ calibration in non-proton MRI.
- This technique is particularly advantageous for hyperpolarized (13)C and (3)He MRI applications.
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