Open ring sign

A.Prof Frank Gaillard et al.

The open ring sign is a relatively specific sign for demyelination, most commonly multiple sclerosis (MS), and is helpful in distinguishing between the causes of ring-enhancing lesions

Radiographic features

The enhancing component is thought to represent advancing front of demyelination and thus favors the white matter side of the lesion. The open part of the ring will therefore usually point towards the grey matter 3.

Treatment and prognosis

Often patients with such lesions undergo biopsy, where the histology can be difficult to interpret. Abundant bizarre astrocytes with frequent mitoses can suggest the diagnosis of glioblastoma. Toxoplasmosis may also be suggested by the presence of giant cells (Creutzfeldt cells).

As such, careful assessment of imaging is essential to avoid unnecessary and misleading intervention. 

White matter disorders
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Article information

rID: 1777
Section: Signs
Synonyms or Alternate Spellings:
  • Incomplete ring enhancement sign
  • Open ring enhancement

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Cases and figures

  • Case 1: ADEM
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  • Case 2: MS
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  • Case 3: MS
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  • Case 4: MS
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