Tubal ring sign

Tubal ring sign, also referred to as bagel sign or blob sign, one of the ultrasound signs of a tubal ectopic. It comprises of an echogenic ring which surrounds an unruptured ectopic pregnancy. It is said to have a 95% positive predictive value (PPV) for ectopic pregnancy.

Differential diagnosis

It can be mimicked by a normal corpus luteum. To differentiate the two, bimanual examination can be useful to differentiate an ovarian corpus luteum (moves with ovary) from a tubal ectopic (moves separately from the ovary). Normal ovarian tissue may also be noticeable around a corpus luteum.

Share article

Article information

rID: 2219
Section: Signs
Tag: stub, cases
Synonyms or Alternate Spellings:
  • Tubal ring sign of an ectopic pregnancy
  • Bagel sign
  • Blob sign

Support Radiopaedia and see fewer ads

Cases and figures

  •  Case I
    Drag here to reorder.
  • Updating… Please wait.

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

     Thank you for updating your details.