Fig. 4.

Representative transverse images from untreated (A) and etoposide-treated (B) mice with s.c.-implanted lymphoma tumors. The ¹H image shows the anatomical location of the tumor, outlined in white. Adjacent to this are false-color CSIs superimposed on the ¹H image, which demonstrate the spatial distribution of the total hyperpolarized ¹³C malate and ¹³C fumarate signals. The color scale indicates the relative signal intensity compared with the maximum intensity in each image. To reduce the effects of noise, voxels with signal intensities ≤20% of the maximum signal intensity were removed from the image. Although the images have been scaled to their respective maxima, the maximum malate signal intensity in each experiment is ≈10–25% of the maximum fumarate signal.