fig 4.

Patient 11: 68-year-old man with a history of a malignant glioma treated with surgical resection, external beam radiation (60 Gy), and interstitial brachytherapy (56 Gy) locally to the tumor bed.

A, Axial T1-weighted MR image obtained 8 weeks after radiation shows an enhancing mass in the right temporal lobe. There is no obvious cavitation/necrosis. The MR spectroscopy voxel is centrally positioned within the enhancing lesion.

B, The MR spectral pattern of a large lipid-lactate peak centered at 1.3 ppm and the absence of discernible Cho, Cr, or NAA were interpreted as consistent with no evidence of tumor. The lesion was completely resected and shown to be an equal mixture of glioblastoma and necrotic tissue. Because of the presence of a significant tumor component, the MR spectroscopy study was considered incorrect.