Bright rim sign (DNET)

The bright rim sign, also known as the hyperintense ring sign, has been described in dysembryoplastic neuroepithelial tumors (DNET). It is described as a well defined rim of high signal around the DNET on FLAIR sequences. This T2/FLAIR hyperintense ring, whether complete or in complete, is fairly sensitive and specific for DNET 2. On post-operative imaging, this sign may be a helpful clue for residual tumor or tumor recurrence 2

On pathologic examination, this bright rim sign corresponds to glioneural elements loosely packed at the margin of the tumor 1 .

This sign can however be very difficult to distiguish from the T2-FLAIR mismatch sign seen in higher-grade astrocytomas.

Malformations of the central nervous system
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Article information

rID: 1017
Section: Signs
Tag: mri, refs, stub
Synonyms or Alternate Spellings:
  • Bright rim sign - DNET
  • Hyperintense rim sign in DNET
  • Hyperintense rim sign in dysembryoplastic neuroepithelial tumours

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