T2-FLAIR mismatch sign

The T2-FLAIR mismatch sign describes the MRI appearance considered highly specific for diffuse or anaplastic astrocytoma (IDH-mutant, 1p/19q-non-codeleted molecular status) as opposed to other lower grade gliomas. On T2WI, the tumor has homogeneously high signal intensity. On T2-FLAIR, the majority of the tumor has relatively hypointense signal, with the exception of a rim of hyperintensity. This appearance is typical of the entity previously known as protoplasmic astrocytoma.

It is important to note that similar signal characteristics can be seen in the bright rim sign of DNET 3.

Article information

rID: 64882
Section: Signs
Synonyms or Alternate Spellings:
  • T2/FLAIR mismatch sign

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Cases and figures

  • Case 1: T2WI of anaplastic astrocytoma
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  • Case 1: FLAIR of anaplastic astrocytoma
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  • Case 2: T2WI of diffuse astrocytoma
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  • Case 2: FLAIR of diffuse astrocytoma
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  • Case 3: T2WI of diffuse astrocytoma
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  • Case 3: FLAIR of diffuse astrocytoma
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  • Case 4: T2WI of diffuse astrocytoma
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  • Case 4: FLAIR of diffuse astrocytoma
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