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Published on: April 15, 2016
Multiband excitation pulses for hyperpolarized 13C dynamic chemical-shift imaging
Peder E Z Larson1, Adam B Kerr, Albert P Chen
1Department of Radiology and Biomedical Imaging, University of California-San Francisco, Byers Hall, Suite 102, 1700 4th Street, San Francisco, CA 94158, USA. peder.larson@radiology.ucsf.edu
Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|July 16, 2008
Summary
This study introduces a novel dynamic chemical-shift imaging method using specialized radiofrequency (RF) pulses to preserve hyperpolarized 13C-pyruvate magnetization. This technique enhances the observation window for metabolic products like lactate and alanine in vivo.
Area of Science:
- Medical Imaging
- Metabolic Imaging
- Magnetic Resonance Imaging
Background:
- Hyperpolarized 13C imaging provides high signal-to-noise ratios for in vivo metabolic studies.
- Magnetization decay and consumption by RF excitation limit imaging duration and sensitivity.
Purpose of the Study:
- To develop a dynamic chemical-shift imaging method that preserves hyperpolarized 13C substrate magnetization.
- To improve signal-to-noise ratio (SNR) for metabolic products while minimizing substrate excitation.
Main Methods:
- Utilized multiband, variable flip angle, spectral-spatial RF pulses for selective excitation.
- Employed spectral selectivity to minimally excite 13C-pyruvate and larger flip angles for metabolic products.
- Incorporated an RF amplitude-insensitive double spin-echo and echo-planar flyback readout gradient.
Main Results:
- Demonstrated improved in vivo imaging in rats and mice compared to constant flip angle pulses.
- Extended the observation window for metabolic products by preserving pyruvate magnetization.
- Achieved better observation of spatially varying metabolic reactions.
Conclusions:
- The developed RF pulse design effectively balances substrate preservation and metabolic product detection.
- This method enhances the utility of hyperpolarized 13C imaging for studying metabolic processes.
- Offers improved visualization of metabolic dynamics in vivo.
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