Presence of a hyperintense FLAIR rim is a reliable indicator of isocitrate dehydrogenase mutation (IDH) in astrocytomas regardless of T2 appearance. The T2-FLAIR mismatch sign (T2FM) shows distinctive temporal radiographic changes and may be seen in high grade gliomas and used with other variables to strengthen IDH prediction status.
Why this matters
The T2FM is highly specific for IDH mutant astrocytomas; however, optimal interpretation of its more variable features remains debatable.
Identification of highly sensitive markers for tumor classification could impact diagnosis and current and future treatment strategies as well as development of novel therapies for brain tumors.