Open ring sign

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. Interestingly open ring enhancement is not seen in neuromyelitis optica (NMO)

Radiographic features

The enhancing component is thought to represent advancing front of demyelination and thus favours 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. 


Share Article

Article Information

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

Support Radiopaedia and see fewer ads

  • Drag
    Case 1: ADEM
    Drag here to reorder.
  • Drag
    Case 2: MS
    Drag here to reorder.
  • Drag
    Active lesion on ...
    Case 3: MS
    Drag here to reorder.
  • Drag
    Case 4: MS
    Drag here to reorder.
  • Updating… Please wait.
    Loadinganimation

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.