IDH2 and oligodendroglioma: For example, a more recent MET PET study by Kim and co-workers reported that in 74 patients with IDH-mutant gliomas of the WHO CNS grade 2 or 3, oligodendrogliomas had significantly higher average median tumor-to-brain ratios than astrocytomas (2.90 vs. 1.40; P < 0.001), but not higher than in patients with IDH-wildtype glioma (n = 70) (averaged median tumor-to-brain ratio, 3.35) [38].