Fig 5. Low-grade ependymoma and anaplastic ependymoma. Short echo time (TE) MR spectra of a low-grade ependymoma (A) and of an anaplastic ependymoma (B) with corresponding MR images indicating the regions of interest. The 2 spectra are scaled according to measured concentration to allow direct comparison. A feature of ependymoma is very low N-acetylaspartate (NAA) signal intensity. In particular, no trace of NAA was found in any of the anaplastic ependymoma. Note that glutamate + glutamine (Glx) relative to creatine (Cr) is more prominent in anaplastic ependymoma.