Tubal ring sign

Dr Henry Knipe and A.Prof Frank Gaillard et al.

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 exam 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.

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Article information

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

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