In vivo 13C magnetic resonance spectroscopy of human brain on a clinical 3 T scanner using [2-13C]glucose infusion and low-power stochastic decoupling.
This study presents the detection of [2-(13)C]glucose metabolism in the carboxylic/amide region in the human brain, and demonstrates that the cerebral metabolism of [2-(13)C]glucose can be studied in human subjects in the presence of severe hardware constraints of widely available 3 T clinical scanners and with low-power stochastic decoupling. In the carboxylic/amide region of human brain, the primary products of (13)C label incorporation from [2-(13)C]glucose into glutamate, glutamine, aspartate, gamma-aminobutyric acid, and N-acetylaspartate were detected. Unlike the commonly used alkanyl region where lipid signals spread over a broad frequency range, the carboxylic carbon signal of lipids was found to be confined to a narrow range centered at 172.5 ppm and present no spectral interference in the absence of lipid suppression. Comparison using phantoms shows that stochastic decoupling is far superior to the commonly used WALTZ sequence at very low decoupling power at 3 T. It was found that glutamine C1 and C5 can be decoupled using stochastic decoupling at 2.2 W, although glutamine protons span a frequency range of approximately 700 Hz. Detailed specific absorption rate analysis was also performed using finite difference time domain numerical simulation.
Li
Shizhe
S
Magnetic Resonance Spectroscopy Core Facility, NIMH, National Institutes of Health, Bethesda, Maryland 20892-1527, USA.
Zhang
Yan
Y
Wang
Shumin
S
Yang
Jehoon
J
Ferraris Araneta
Maria
M
Farris
Amanda
A
Johnson
Christopher
C
Fox
Stephen
S
Innis
Robert
R
Shen
Jun
J
D000465:Algorithms; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D002247:Carbon Isotopes / Q000008:administration & dosage / Q000493:pharmacokinetics; D003199:Computer Systems; D005947:Glucose / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006801:Humans; D007262:Infusions, Intravenous; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D013269:Stochastic Processes; D014018:Tissue Distribution
D002247:Carbon Isotopes; D005947:Glucose