title: Robust and high resolution hyperpolarized metabolic imaging of the rat heart at 7 T with 3D spectral-spatial EPI.
abstract: OBJECTIVE
  Hyperpolarized metabolic imaging has the potential to revolutionize the diagnosis and management of diseases where metabolism is dysregulated, such as heart disease. We investigated the feasibility of imaging rodent myocardial metabolism at high resolution at 7 T.
  
  
  METHODS
  We present here a fly-back spectral-spatial radiofrequency pulse that sidestepped maximum gradient strength requirements and enabled high resolution metabolic imaging of the rodent myocardium. A 3D echo-planar imaging readout followed, with centric ordered z-phase encoding. The cardiac gated sequence was used to image metabolism in rodents whose metabolic state had been manipulated by being fasted, fed, or fed and given the pyruvate dehydrogenase kinase inhibitor dichloroacetate.
  
  
  RESULTS
  We imaged hyperpolarized metabolites with a spatial resolution of 2×2×3.8 mm(3) and a temporal resolution of 1.8 s in the rat heart at 7 T. Significant differences in myocardial pyruvate dehydrogenase flux were observed between the three groups of animals, concomitant with the known biochemistry.
  
  
  CONCLUSIONS
  The proposed sequence was able to image in vivo metabolism with excellent spatial resolution in the rat heart. The field of view enabled the simultaneous multi-organ acquisition of metabolic information from the rat, which is of great utility for preclinical research in cardiovascular disease. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance.
authors.affiliation: Department of Physics, Clarendon Laboratory, University of Oxford, England, UK.|Department of Physiology, Anatomy & Genetics, University of Oxford, England, UK.|Department of Oncology, Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, England, UK.
authors.forename: Jack J
authors.initials: JJ
authors.lastname: Miller
authors.affiliation: Department of Physiology, Anatomy & Genetics, University of Oxford, England, UK.|Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, England, UK.
authors.forename: Angus Z
authors.initials: AZ
authors.lastname: Lau
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, England, UK.
authors.forename: Irvin
authors.initials: I
authors.lastname: Teh
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, England, UK.
authors.forename: Jürgen E
authors.initials: JE
authors.lastname: Schneider
authors.affiliation: Department of Oncology, Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, England, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Kinchesh
authors.affiliation: Department of Oncology, Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, England, UK.
authors.forename: Sean
authors.initials: S
authors.lastname: Smart
authors.affiliation: Department of Physiology, Anatomy & Genetics, University of Oxford, England, UK.
authors.forename: Vicky
authors.initials: V
authors.lastname: Ball
authors.affiliation: Department of Oncology, Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, England, UK.
authors.forename: Nicola R
authors.initials: NR
authors.lastname: Sibson
authors.affiliation: Department of Physiology, Anatomy & Genetics, University of Oxford, England, UK.|Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, England, UK.
authors.forename: Damian J
authors.initials: DJ
authors.lastname: Tyler
mesh_terms: D000465:Algorithms; D000818:Animals; D002247:Carbon Isotopes / Q000378:metabolism*; D017352:Echo-Planar Imaging / Q000379:methods*; D006321:Heart / Q000000981:diagnostic imaging*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D059629:Signal-To-Noise Ratio
chemical_list: D002247:Carbon Isotopes
keywords: cardiac imaging; cardiac metabolism; hyperpolarized 13C; metabolic imaging; pulse sequences; pyruvate