Bernard Lanz1,
Lijing Xin1, Rolf Gruetter1,2
1Laboratory for functional and
metabolic imaging, Ecole Polytechnique Fdrale de Lausanne, Lausanne,
Switzerland; 2Departments of Radiology, Universities of Lausanne
and Geneva, Lausanne and Geneva, Switzerland
[2-13C]acetate
infusion coupled with 13C MRS enables the separated assessment of
glial and neuronal Krebs cycle fluxes with higher accuracy than 13C
labeled glucose, due to the asymetric metabolism of acetate in the brain.
However, the faster neuronal Krebs cycle induces a strong dilution of the 13C
labeled glutamate on the neuronal side, resulting in lower 13C MRS
signal than with glucose. In this study, we analyzed with Monte-Carlo
simulations the precision of the fitted metabolic fluxes with separated
GluC3/GlnC3 curves obtained with 1H{13C} MRS as well as
the impact of the neuroglial partition of glutamate on the fluxes.