Fig. 4

A patient aged 20–25 years with cerebral inflammatory lesion. T2-weighted MRI (a) shows a high signal lesion within the left frontal white matter (arrow). The lesion exhibits increased uptake of ¹⁸F-FDG (b) with equal uptake of ¹³N-NH₃ (c) and ¹¹C-MET (d) compared with contralateral normal brain parenchyma. Repeated MRI (e) shows that the lesion disappeared