Yun Xiang1, Jun Shen1
1National Institute of Mental Health,
In the carboxylic/amide region, brain 13C signals can only have one one-bond 13C-13C homonuclear coupling. As such only doublets (with a 13C-13C coupling of ~50 Hz) and singlets exist in this region. The large one-bond 13C-13C J coupling and the lack of interference from other isotopomers provide a unique condition for simultaneous detection of metabolism of different substrates. Examples of co-infusion of [13C6]-D-glucose and [1-13C] acetate as well as co-infusion of [13C6]-D-glucose and [1,3-13C2] hydroxybutyrate are shown to demonstrate in vivo simultaneous detection of different metabolic pathways in the brain using 13C MRS of the carboxylic/amide region.