IDH1 and glioma: Multiple recent studies have attempted to correlate T2–FLAIR mismatch with IDH and 1p/19q codeletion status in lower-grade gliomas.38,39 For example, MRIs of 125 lower-grade gliomas from the TCIA dataset were evaluated by 2 independent neuroradiologists to assess for the presence/absence of T2–FLAIR mismatch sign.38 All 15 cases declared positive by the readers for the T2–FLAIR mismatch sign were IDH-mutant 1p/19q-noncodeleted tumors.