MRI - Oligodendroglioma: This 18-year-old woman presented with new onset seizures primarily involving the right hemibody. Her examination showed right-sided visual extinction to confrontation. The T1-weighted axial MR image on the left shows a lesion in the left parieto-occipital region with surrounding mass effect and edema. Following infusion of intravenous gadolinium (right panel), the lesion has a low intensity central region surrounded by an area of contrast enhancement.