T2-FLAIR Mismatch Sign Is Caused by Long T1 and T2 of IDH-mutant, 1p19q Non-codeleted Astrocytoma

T-2-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-2-FLAIR mismatch exhibited extremely long T-1- and T-2-relaxation time while T-2-FLAIR matched lesions showed low to moderate values. On the other hand, IDH-wildtype tumors presented noticeably short T-1- and T-2-relaxation time. These different relaxation time characteristics seemed to render T-2-FLAIR mismatch sign of becoming such a unique and specific image feature for IDH-mutant, 1p19q non-codeleted astrocytoma.

Automated summary

The T-2-fluid-attenuated inversion recovery images (FLAIR) mismatch sign is a specific yet insensitive image feature for IDH-mutant, 1p19q non-codeleted astrocytoma. Lesions with T-2-FLAIR mismatch show long T-1 and T-2-relaxation time, while matched lesions exhibit low to moderate values. In contrast, IDH-wildtype tumors have short T-1 and T-2-relaxation time, making the T-2-FLAIR mismatch sign a unique and specific feature for identifying certain types of astrocytoma.