title: Feasibility of mapping unidirectional Pi-to-ATP fluxes in muscles of the lower leg at 7.0 Tesla.
abstract: OBJECTIVE
  To assess the feasibility of mapping the kinetics and unidirectional fluxes of inorganic phosphate (Pi) to adenosine triphosphate (ATP) reactions in the entire volume of the lower leg muscles using a three-dimensional saturation transfer (ST) phosphorus (31P) imaging sequence.
  
  
  METHODS
  We imaged the lower leg muscles of five healthy subjects at 7.0 Tesla. The total experimental time was 45 min. We quantified muscle-specific forward reaction rate constants (k'f) and metabolic fluxes (Vf) of the Pi-to-ATP reaction in the tibialis anterior, the gastrocnemius, and the soleus.
  
  
  RESULTS
  In the tibialis anterior, k'fand Vfwere 0.11 s-1± 0.03 (mean ± standard deviation) and 0.34 mM s-1± 0.10, respectively. In the gastrocnemius, k'fwas 0.11 s-1± 0.04 and Vfwas 0.37 mM s-1± 0.11, while in the soleus muscle k'fwas 0.10 s-1± 0.02 and Vfwas 0.36 mM s-1± 0.14.
  
  
  CONCLUSIONS
  Our results suggest that mapping the kinetics and unidirectional fluxes from Pi-to-ATP in both the anterior and posterior muscles of the lower leg is feasible at ultra-high field and may provide useful insights for the study of insulin resistance, diabetes and aging. Magn Reson Med 74:225-230, 2015. © 2014 Wiley Periodicals, Inc.
authors: Quantitative Multinuclear Musculoskeletal Imaging Group (QMMIG), Department of Radiology, Center for Biomedical Imaging, New York University Langone Medical Center, New York, New York, USA.
authors: Prodromos
authors: P
authors: Parasoglou
authors: Quantitative Multinuclear Musculoskeletal Imaging Group (QMMIG), Department of Radiology, Center for Biomedical Imaging, New York University Langone Medical Center, New York, New York, USA.
authors: Ding
authors: D
authors: Xia
authors: Quantitative Multinuclear Musculoskeletal Imaging Group (QMMIG), Department of Radiology, Center for Biomedical Imaging, New York University Langone Medical Center, New York, New York, USA.
authors: Ravinder R
authors: RR
authors: Regatte
keywords: 31P-MRI; musculoskeletal MRI; nonproton MRI; saturation transfer