Figure 3.

An example of the proton spectra (echo time=30 ms) within and surrounding a World Health Organization grade III anaplastic astrocytoma. The first region is within normal brain and the normal spectra can be seen with high N-acetylaspartate (NAA) peaks and a lower choline peak. The second spectrum is taken from the peritumoural tissue where there is a much higher choline peak and a lower NAA peak. NAA is still detectable suggesting viable neurons are still present. Within the tumour there is a very high choline peak but NAA is undetectable.