FIGURE 5.

In vivo ¹³C spectra in the rat brain after infusion of 70%-enriched [1,6-¹³C₂]glucose and mouse brain after infusion of 70%-enriched [U-¹³C₆]glucose. A-C, Rat. A, RF coil, viewed from the top, consisting of a ¹H quadrature surface coil (two loops of 14 mm diameter) and an inner ¹³C linearly polarized surface coil (12 mm diameter). B, The MRS voxel, shown on axial and sagittal T₂ images, was 9 × 5 × 9 mm³ (400 mL). C, Spectrum acquired using a semi-adiabatic DEPT sequence.¹⁴² Data were acquired for 1.8 h (2560 averages, TR 2.5 s) starting 1.8 h after the beginning of glucose infusion. D-F, Mouse. D, RF coil, viewed from the top, consisting of a ¹H quadrature surface coil (two loops of 13 mm diameter) and an inner ¹³C linearly polarized surface coil (10 mm diameter). E, Representative coronal and sagittal fast spinecho images of the mouse brain with the VOI for ¹³C MRS measurement. F, Averaged edited ¹H-[¹³C] MR spectra acquired in the mouse brain during the first hour of [U-¹³C₆] glucose infusion (VOI = 60 μL, 960 averages, TR = 4.0 s)¹⁴⁰