- Marco‐Rius, Irene;
- Cao, Peng;
- von Morze, Cornelius;
- Merritt, Matthew;
- Moreno, Karlos X;
- Chang, Gene‐Yuan;
- Ohliger, Michael A;
- Pearce, David;
- Kurhanewicz, John;
- Larson, Peder EZ;
- Vigneron, Daniel B
Purpose
To develop a specialized multislice, single-acquisition approach to detect the metabolites of hyperpolarized (HP) [2-13 C]dihydroxyacetone (DHAc) to probe gluconeogenesis in vivo, which have a broad 144 ppm spectral range (∼4.6 kHz at 3T). A novel multiband radio-frequency (RF) excitation pulse was designed for independent flip angle control over five to six spectral-spatial (SPSP) excitation bands, each corrected for chemical shift misregistration effects.Methods
Specialized multiband SPSP RF pulses were designed, tested, and applied to investigate HP [2-13 C]DHAc metabolism in kidney and liver of fasted rats with dynamic 13 C-MR spectroscopy and an optimal flip angle scheme. For comparison, experiments were also performed with narrow-band slice-selective RF pulses and a sequential change of the frequency offset to cover the five frequency bands of interest.Results
The SPSP pulses provided a controllable spectral profile free of baseline distortion with improved signal to noise of the metabolite peaks, allowing for quantification of the metabolic products. We observed organ-specific differences in DHAc metabolism. There was two to five times more [2-13 C]phosphoenolpyruvate and about 19 times more [2-13 C]glycerol 3-phosphate in the liver than in the kidney.Conclusion
A multiband SPSP RF pulse covering a spectral range over 144 ppm enabled in vivo characterization of HP [2-13 C]DHAc metabolism in rat liver and kidney. Magn Reson Med 77:1419-1428, 2017. © 2016 International Society for Magnetic Resonance in Medicine.