title: Multiband spectral-spatial RF excitation for hyperpolarized [2-13C]dihydroxyacetone13C-MR metabolism studies.
abstract: To develop a specialized multislice, single-acquisition approach to detect the metabolites of hyperpolarized (HP) [2-13C]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.
  
  
  
  Specialized multiband SPSP RF pulses were designed, tested, and applied to investigate HP [2-13C]DHAc metabolism in kidney and liver of fasted rats with dynamic13C-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.
  
  
  
  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 [2-13C]phosphoenolpyruvate and about 19 times more [2-13C]glycerol 3-phosphate in the liver than in the kidney.
  
  
  
  A multiband SPSP RF pulse covering a spectral range over 144 ppm enabled in vivo characterization of HP [2-13C]DHAc metabolism in rat liver and kidney. Magn Reson Med 77:1419-1428, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
authors.forename: Irene
authors.initials: I
authors.lastname: Marco-Rius
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
authors.forename: Peng
authors.initials: P
authors.lastname: Cao
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
authors.forename: Cornelius
authors.initials: C
authors.lastname: von Morze
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Merritt
authors.affiliation: Department of Chemistry, Engineering, Pre-Pharmacy, and Physics, South Texas College, Weslaco, Texas, USA.
authors.forename: Karlos X
authors.initials: KX
authors.lastname: Moreno
authors.affiliation: Department of Medicine, Division of Nephrology, University of California San Francisco, San Francisco, California, USA.
authors.forename: Gene-Yuan
authors.initials: GY
authors.lastname: Chang
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Ohliger
authors.affiliation: Department of Medicine, Division of Nephrology, University of California San Francisco, San Francisco, California, USA.
authors.forename: David
authors.initials: D
authors.lastname: Pearce
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
authors.forename: John
authors.initials: J
authors.lastname: Kurhanewicz
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
authors.forename: Peder E Z
authors.initials: PE
authors.lastname: Larson
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Vigneron
mesh_terms: D000818:Animals; D066241:Carbon-13 Magnetic Resonance Spectroscopy / Q000379:methods*; D004098:Dihydroxyacetone / Q000378:metabolism*; D005943:Gluconeogenesis / Q000502:physiology; D005947:Glucose / Q000096:biosynthesis*; D007668:Kidney / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
chemical_list: D005947:Glucose; D004098:Dihydroxyacetone
keywords: dihydroxyacetone; dynamic nuclear polarization; hyperpolarization; kidney; liver; metabolic imaging; multiband RF pulses; spectral-spatial RF pulses