A, example of CSI MRSI data set from a PC-3-5HRE-EGFP tumor (550 mm3) obtained with a spatial resolution of 0.5 mm ×0.5 mm ×4.0 mm. B, spectrum from a single 0.5 mm at ×0.5 mm ×4.0 mm voxel showing tCho 3.2 ppm and lactate/triglycerides (lac/triglyc) at 1.3 ppm (TE = 272 ms). C, triplanar view of a tCho map (displayed in red) generated from the data set shown in Fig. 2A, fused with the corresponding spin-echo image displayed in blue. D, EGFP expression in hypoxic regions in a fresh tissue slice matching the MRSI slice, overlaid on a white light image. Comparison of C and D reveals a coarse colocalization between the tCho and EGFP distributions.