This 44 year old lady had generalized seizures 1 year back and her MRI brain had shown a non-enhancing right frontal lesion. She had received gamma knife radiation for that lesion and now presented with recurrent seizures and left hemiparesis. Brain MRI and perfusion scan are being shared. What is the most likely diagnosis?
- High-grade glioma
- Radiation necrosis
- Metastasis
- Low-grade glioma
- Ischemic infarct
Answer
Congratulations to those who selected radiation necrosis. It is difficult to differentiate between high-grade glioma and radiation necrosis on the contrast enhancement pattern. But the history of radiation during the last year and the purple color pattern on the perfusion scan showing nearly absent perfusion in the affected area were the deciding factors.