13C-Glucose Labeling Effects measured in the Occipital Lobe and the Frontal Cortex using short TE 1H MC-semiLASER SVS at 9.4T
Theresia Ziegs1,2, Johanna Dorst1,2, and Anke Henning1,3
1MRZ, MPI for Biological Cybernetics, Tuebingen, Germany, 2IMPRS for Cognitive and Systems Neuroscience, Tuebingen, Germany, 3Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
Labeling effects after oral intake of [13C-1]glucose are observed in humans using a 1H MC-semiLASER sequence at 9.4 T. Spectral time series acquired in the frontal cortex as well as the occipital lobe show labelling induced changes of  Glu and Gln spectral pattern directly detected with 1H MRS.
Figure 2: Time series of the MC-semiLASER spectra from the occipital lobe (left) and frontal cortex (right) and the corresponding difference spectra underneath. The difference spectra in the spectral region of interest between 1.9 and 2.8 is zoomed in to make changes more visible. The colorbar indicates the time of the (difference) spectra after the glucose administration. Changes in the spectral region of NAA and Cr can occur due to subtraction errors.
Figure 3: a) 1H MC-semiLaser spectrum from one volunteer of the occipital lobe before glucose administration (black line) and 127 minutes after the administration (red line) and the difference spectrum (blue line). Obvious peak changes are marked: Decreasing peaks are marked in purple and increasing peaks are marked in green. The spectra contain 64 averages. b) Simulated spectra for selected metabolites and labeled metabolites.