Ovarian torsion?

Sudden severe pelvic pain, often with nausea; the ovary is salvaged by the surgeon's clock, not the radiologist's certainty.

Answer the surgeon

Gynecologic laparoscopy for detorsion — the decision is clinical plus imaging, not Doppler alone.

Your answer must state:

Ovarian size vs the contralateral side — unilateral enlargement >4 cm is the workhorse sign
Peripheralized follicles with central stromal edema
Twisted vascular pedicle (whirlpool)
Flow: present, reduced, or absent — and that preserved flow does not exclude torsion
A lead-point lesion: dermoid, cyst
Ovary displaced toward the midline; free fluid

Key and direct findings

1.Enlarged edematous ovary
Unilateral enlargement (>4 cm or clearly asymmetric volume) with heterogeneous edematous stroma is the most consistent finding.
2.Twisted vascular pedicle
The whirlpool of the twisted pedicle between ovary and uterus is the direct sign — pathognomonic when seen.
3.Doppler flow — interpret with care
Absent venous flow is the more sensitive clue; arterial flow often persists because of the dual ovarian and uterine arterial supply.
Pitfall: Preserved arterial flow occurs in a substantial share of surgically proven torsions — never exclude torsion on flow alone.

Supportive signs & checks

1.Peripheral follicles
Small follicles pushed to the rim of an edematous ovary — the 'string of pearls' of torsion.
2.Lead-point lesion and position
A dermoid or cyst acting as the fulcrum, and an ovary displaced to the midline or anteriorly, both support the diagnosis.
Pitfall: A hemorrhagic cyst can mimic the enlarged painful ovary — the twisted pedicle and stromal edema separate them.
3.Intermittent torsion
Between episodes the exam can look confusingly normal — with a classic history, say torsion is not excluded.

Wet-read snippets

Fill the blanks, then copy into your preliminary report.

Positive

Findings concerning for ovarian torsion: ___ ovary enlarged (___ cm vs ___ cm), stromal edema with peripheral follicles, ___ (twisted pedicle / absent venous flow). Gynecology notified.

Negative

Ovaries symmetric in size with normal arterial and venous flow bilaterally, no pedicle twist — no US evidence of torsion at this time.

Equivocal

Enlarged ___ ovary with preserved flow — torsion is not excluded (dual supply); correlate clinically and consider urgent gynecology review.

Sources

ACR Appropriateness Criteria: Acute Pelvic Pain in the Reproductive Age Group — American College of Radiology (2023)
Adnexal torsion: review of radiologic appearances — Dawood MT et al. RadioGraphics (2021)

Content review: Content pending clinical review · 2026-07-15

Educational reference for trained clinicians. Verify every result against the cited original guideline before use. Not a substitute for clinical judgment or medical advice.