IDH1 and astrocytoma (excluding glioblastoma): A more medial component centered in the superior frontal gyrus consisted of a large circumscribed rounded T1-hypointense and T2-hyperintense area with central signal suppression on FLAIR images (the “T2-FLAIR mismatch sign”) indicative of IDH-1 mutant 1p/19q non-codeleted astrocytoma.