In a reproductive‑age woman presenting with acute severe lower abdominal or pelvic pain, nausea, and a possible adnexal mass, can a pelvic ultrasound with Doppler flow assessment reliably rule out ovarian torsion?

Can Pelvic Ultrasound Rule Out Ovarian Torsion?

No, pelvic ultrasound cannot reliably rule out ovarian torsion, and normal Doppler flow does not exclude the diagnosis. Clinical suspicion must drive management decisions, as imaging serves only to support—not exclude—this surgical emergency.

Critical Diagnostic Limitations

Normal Doppler Flow Does Not Exclude Torsion

• Normal arterial blood flow is present in a substantial proportion of confirmed ovarian torsion cases and should never be used to exclude the diagnosis 1, 2.
• In surgically proven cases, 61% of right ovarian torsions and 27% of left ovarian torsions demonstrated normal Doppler flow 3.
• Color flow (either venous or arterial) was documented in 62% of pathologically confirmed torsed ovaries 4.
• The presence of arterial flow suggests the ovary may still be viable, particularly if flow is present centrally, but does not rule out torsion 5.

Venous Flow Assessment Is More Sensitive But Not Perfect

• Abnormal or absent ovarian venous flow has the highest diagnostic accuracy, with 100% sensitivity and 97% specificity in prospective studies 1, 6, 7.
• However, venous flow assessment requires technical expertise and optimal imaging conditions that may not always be achievable in emergency settings 7.
• In early or intermittent torsion, abnormal venous flow may be the only sonographic abnormality, with normal grayscale appearance and normal arterial flow 7.

Ultrasound Performance Characteristics

Overall Diagnostic Accuracy

• Doppler ultrasound has only 80% sensitivity and 88% specificity for diagnosing ovarian torsion 1.
• Grayscale ultrasound alone performs even worse, with 79% sensitivity and 76% specificity 1.
• The combined transabdominal and transvaginal approach with Doppler achieves 96% overall accuracy, but this still means 4% of cases may be missed 6.
• Some studies report correct ultrasound diagnosis in only 23% to 66% of cases, highlighting significant variability in real-world performance 3.

Key Supportive Findings (When Present)

• Unilaterally enlarged ovary (>4 cm or volume >20 cm³) is found in up to 74% of cases 1, 6.
• The whirlpool sign (twisted vascular pedicle) has 90% sensitivity when present 1, 2, 6.
• Peripheral follicles in a "string of pearls" pattern support the diagnosis 6.
• All torsed adnexa are larger than the contralateral normal ovary, with median volume 12 times greater 4.

Clinical Decision-Making Algorithm

When Ultrasound Is Positive or Equivocal

• Proceed directly to urgent gynecologic consultation for surgical management when clinical suspicion is high, regardless of Doppler findings 1, 2.
• Do not delay surgery based on preserved arterial flow, as torsion can be intermittent or partial 1, 2.

When Ultrasound Appears Normal But Clinical Suspicion Remains High

• Consider MRI (80-85% sensitivity) as the preferred second-line modality if the patient is stable enough for additional imaging 1, 2, 6.
• CT abdomen/pelvis with IV contrast (74-95% sensitivity) is an alternative when MRI is unavailable or when non-gynecologic pathology needs exclusion 1, 6.
• In unstable patients or those with compelling clinical features (severe constant pain, palpable adnexal mass, nausea), proceed directly to diagnostic laparoscopy without additional imaging 1.

Critical Pitfalls to Avoid

• Never use normal Doppler flow to exclude ovarian torsion—this is the most common diagnostic error leading to delayed management 1, 3.
• Ovarian torsion is fundamentally a clinical diagnosis that requires integration of presentation, physical examination findings, and imaging—not imaging alone 3.
• The American College of Radiology explicitly recommends against using Doppler flow as a definitive exclusionary criterion 1.
• Early detection is essential, as delayed diagnosis leads to adnexal necrosis and infertility 1.

Recommended First-Line Imaging Approach

• Perform combined transabdominal and transvaginal ultrasound with color and spectral Doppler as the initial study 8, 1, 6.
• Transvaginal ultrasound provides superior resolution for ovarian architecture and the whirlpool sign 6.
• Transabdominal ultrasound offers better assessment of high-lying adnexa and free pelvic fluid 6.
• Document ovarian size, presence of masses, peripheral follicles, whirlpool sign, and both arterial and venous flow patterns 1, 6.