Optimized [1-13C]glucose infusion protocol for 13C magnetic resonance spectroscopy at 3 Tesla of human brain glucose metabolism under euglycemic and hypoglycemic conditions

The effect of insulin-induced hypoglycemia on cerebral glucose metabolism is largely unknown. 13 C MRS is a unique tool to study cerebral glucose metabolism, but the concurrent requirement for [1- 13 C]glucose administration limits its use under hypoglycemic conditions. To facilitate 13C MRS data analysis we designed separate [1- 13 C]glucose infusion protocols for hyperinsulinemic euglycemic and hypoglycemic clamps in such a way that plasma isotopic enrichment of glucose was stable and comparable under both glycemic conditions. 13 C MR spectra were acquired with optimized 13 C MRS measurement techniques to obtain high quality 13 C MR spectra with these protocols.