T-FLAIR Mismatch Sign Is Caused by Long T and T of IDH-mutant, 1p19q Non-codeleted Astrocytoma.

T-fluid-attenuated inversion recovery images (FLAIR) mismatch sign is now known to be a specific yet insensitive image feature for IDH-mutant, 1p19q non-codeleted astrocytoma. The current study revealed that lesion presenting T-FLAIR mismatch exhibited extremely long T- and T-relaxation time while T-FLAIR matched lesions showed low to moderate values. On the other hand, IDH-wildtype tumors presented noticeably short T- and T-relaxation time. These different relaxation time characteristics seemed to render T-FLAIR mismatch sign of becoming such a unique and specific image feature for IDH-mutant, 1p19q non-codeleted astrocytoma.