- In white matter adjacent to irradiated cerebral tumor
- Adjacent brain tissue in field of head and neck tumor radiation therapy
- Radiation causes cerebral small vessel alterations, wall thickening and direct glial and lesser extent neuronal injury
- Ring-enhancing lesion, areas of hemorrhage, surrounded by edema
- Difficult to distinguish from tumor recurrence
- Increased diffusivity on DWI
- Low cerebral blood volume
- Low choline on spectroscopy
- Reduced metabolic avtivity
- Tumors show decreased diffusivity, increased cerebral blood volume, high levels of choline, elevated metabolic activity
Barajas Jr, Ramon F., et al. “Differentiation of recurrent glioblastoma multiforme from radiation necrosis after external beam radiation therapy with dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging.” Radiology 253.2 (2009): 486-496.
Barajas, R. F., et al. “Distinguishing recurrent intra-axial metastatic tumor from radiation necrosis following gamma knife radiosurgery using dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging.” American journal of neuroradiology 30.2 (2009): 367-372.