IN-VIVO 3D LOCALIZED C-13 SPECTROSCOPY USING MODIFIED INEPT AND DEPT

The 3D localized C-13 spectroscopy methods LINEPT and LODEPT, which ar e modifications of INEPT and DEFT, are proposed. As long as a C-13 inv ersion pulse (180-degree pulse) is applied at 1/(4J) before the proton echo time in LINEPT and a C-13 excitation pulse (90-degree pulse) is applied at 1/(2J) before the proton echo time in LODEPT, the proton ec ho time can be set to any value longer than 1/(2J) in LINEPT and longe r than 1/J in LODEPT. As a result, the proton and the C-13 pulses can be applied separately and these proton pulses can be made slice-select ive pulses. These localization features of LINEPT and LODEPT were eval uated using a phantom consisting of a cylinder filled with ethanol pla ced inside another cylinder filled with oil, and localized ethanol spe ctra could be obtained. In vivo 3D localized C-13 spectra from the bra in of a monkey could be obtained using decoupled LINEPT, and glutamate C-4 appeared directly after the administration of glucose C-1, follow ed by the appearance of glutamate C-2, C-3 and glutamine C-2, C-3, C-4 . (C) 1998 Academic Press.