FIGURE 4.
Z−spectra and magnetization transfer ratio asymmetry (MTRasym) maps obtained on a glioma-implanted rat for two different points in time, under low γB1 saturating conditions. Top row: results observed 7 days after 9 L glioma cell injection. Bottom row: results observed 11 days after 9L glioma cell injection. A, Anatomical rapid acquisition with relaxation enhancement (RARE) images showing the regions of interest (ROIs) of normal brain and diseased regions. Notice the weak contrast between the two. B, Localized Z−spectra extracted from normal brain (green) and glioma (red) tissues. C, Corresponding MTRasym spectra. D, MTRasym maps extracted at the chemical shift of maximum contrast (indicated in blue in C) for this particular animal