title: Quantification of Intramyocardial Metabolites by Proton Magnetic Resonance Spectroscopy.
abstract: OBJECTIVE
  To define intramyocardial triglyceride (TG), creatine (Cr), and choline (Cho) in healthy volunteers, and determine the feasibilities, scan durations and agreements between cardiac proton magnetic resonance spectroscopy ([(1)H]-MRS) performed with fewer signal averages versus a reference standard with 128 signal averages.
  
  
  METHODS
  Thirty-one participants underwent [(1)H]-MRS using 16, 32, 64, and 128 signal averages. Intramyocardial TG, Cr, or Cho contents relative to water were calculated and expressed as a percentage.
  
  
  RESULTS
  Mean intramyocardial TG, Cr, and Cho were 1.30 ± 1.13, 0.19 ± 0.18, and 0.24 ± 0.28%, respectively. The feasibilities for quantifying intramyocardial TG, Cr, and Cho using fewer signal averages ranged from 93.5 to 100, 90.3 to 93.5, and 90.3 to 96.8%, respectively. Scan durations for 16, 32, 64, and 128 signal averages were 1.1 ± 0.5, 2.6 ± 0.9, 5.9 ± 2.0, and 13.2 ± 4.5 min, respectively (p < 0.001). Agreements with the reference standard 128 signal average was higher for quantification of intramyocardial TG compared to Cr and Cho.
  
  
  CONCLUSIONS
  Quantification of intramyocardial TG with [(1)H]-MRS with only 64 signal averages was highly feasible, showed excellent agreement with 128 signal averages, and had significantly shorter scan duration. By contrast, quantifying Cr and Cho using fewer signal averages had lower feasibilities and agreements compared to 128 signal averages.
authors.affiliation: Department of Cardiology, Princess Alexandra Hospital, The University of Queensland , Brisbane, QLD , Australia.
authors.forename: Lisa
authors.initials: L
authors.lastname: Gillinder
authors.affiliation: Department of Cardiology, Princess Alexandra Hospital, The University of Queensland , Brisbane, QLD , Australia.
authors.forename: Shi Yi
authors.initials: SY
authors.lastname: Goo
authors.affiliation: Centre for Advanced Imaging, The University of Queensland , Brisbane, QLD , Australia.
authors.forename: Gary
authors.initials: G
authors.lastname: Cowin
authors.affiliation: Centre for Advanced Imaging, The University of Queensland , Brisbane, QLD , Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Strudwick
authors.affiliation: Department of Radiology, Leiden University Medical Center , Leiden , Netherlands.
authors.forename: Rob J
authors.initials: RJ
authors.lastname: van der Geest
authors.affiliation: Department of Cardiology, Princess Alexandra Hospital, The University of Queensland , Brisbane, QLD , Australia ; Centre for Advanced Imaging, The University of Queensland , Brisbane, QLD , Australia.
authors.forename: William Y S
authors.initials: WY
authors.lastname: Wang
authors.affiliation: Department of Cardiology, Princess Alexandra Hospital, The University of Queensland , Brisbane, QLD , Australia ; Centre for Advanced Imaging, The University of Queensland , Brisbane, QLD , Australia.
authors.forename: Arnold C T
authors.initials: AC
authors.lastname: Ng
keywords: left ventricle; magnetic resonance; metabolites; myocardial; spectroscopy