Figure 8.

The Cho/NAA map identifies regions of elevated SOX2 expression near regions of contrast enhancement in a 43-year-old patient (patient 5 in Supplemental Table 1) with recurrent anaplastic astrocytoma (A–C). Significant Cho/NAA abnormalities span the edematous region between contrast-enhancing foci before surgery. MRI at recurrence shows contrast enhancement growing toward the center of the foci, taking a shape similar to the abnormality in the prebiopsy Cho/NAA map (D). A whole-slide scan of tissue from the green box (E), along with a 17× view of that tissue at the white box (F), showed elevations in SOX2 density and nuclear atypia. Punctate, high-intensity voxels at the edge of the sMRI map are spectral artifacts resulting from tissue susceptibility changes. In this case, the artifact at the lateral aspect of the tumor (white arrow) where a metal plate secures a bone flap from a previous excisional biopsy is particularly prominent.