RESUMO
Hyperpolarized (HP) 13C Magnetic Resonance Imaging (MRI) was applied for the first time to image and quantify the uptake and metabolism of [2-13C]pyruvate in the human brain to provide new metabolic information on cerebral energy metabolism. HP [2-13C]pyruvate was injected intravenously and imaged in 5 healthy human volunteer exams with whole brain coverage in a 1-minute acquisition using a specialized spectral-spatial multi-slice echoplanar imaging (EPI) pulse sequence to acquire 13C-labeled volumetric and dynamic images of [2-13C]pyruvate and downstream metabolites [5-13C]glutamate and [2-13C]lactate. Metabolic ratios and apparent conversion rates of pyruvate-to-lactate (kPL) and pyruvate-to-glutamate (kPG) were quantified to investigate simultaneously glycolytic and oxidative metabolism in a single injection.
Assuntos
Imageamento por Ressonância Magnética , Ácido Pirúvico , Humanos , Encéfalo/diagnóstico por imagem , Ácido Glutâmico , Ácido Láctico , Imagem MolecularRESUMO
We developed methods for the preparation of hyperpolarized (HP) sterile [2-13C]pyruvate to test its feasibility in first-ever human NMR studies following FDA-IND & IRB approval. Spectral results using this MR stable-isotope imaging approach demonstrated the feasibility of investigating human cerebral energy metabolism by measuring the dynamic conversion of HP [2-13C]pyruvate to [2-13C]lactate and [5-13C]glutamate in the brain of four healthy volunteers. Metabolite kinetics, signal-to-noise (SNR) and area-under-curve (AUC) ratios, and calculated [2-13C]pyruvate to [2-13C]lactate conversion rates (kPL) were measured and showed similar but not identical inter-subject values. The kPL measurements were equivalent with prior human HP [1-13C]pyruvate measurements.