Alternative 1-13C glucose infusion protocols for clinical 13C MRS examinations of the brain

Clinical utility of C-13 MRS is limited by cost and long examination times. Three 1-C-13 glucose infusion protocols-a high-dose i.v., low-dose i.v., and oral administration of 1-C-13 glucose-were compared on a GE 1.5T MR scanner. Resolution and sensitivity were sufficient to identify C-13 glucose (1 alpha and 1 beta), glutamate (C1-C4), glutamine (C1-C4), aspartate (C2 and C3), lactate, alanine, and bicarbonate in brain spectra. The three protocols were efficacious, as measured by cerebral enrichment of 1-C-13 glucose (62%, 42%, and 38%) and its principal metabolite, 4-C-13 glutamate (13%, 11%, and 16%), respectively. Intravenous infusion of 1-C-13 glucose 0.23 g/kg body weight (low dose) provides equivalent information at one third the cost of previous regimes. (C) 2001 Wiley-Liss, Inc.