How should I differentiate between ovarian torsion and other causes of acute abdominal pain in women?

To differentiate ovarian torsion from other causes of acute abdominal pain in women, focus on clinical presentation, imaging findings, and risk factors.

Ovarian torsion typically presents with sudden onset, severe unilateral lower abdominal pain often accompanied by nausea and vomiting, which may be intermittent or constant. This contrasts with other causes of acute abdominal pain that may have different pain characteristics or associated symptoms ¹.

On physical examination, adnexal tenderness and a palpable mass may be present, but these signs are not specific. Therefore, imaging is crucial for differentiation.

Ultrasound with Doppler is the first-line imaging modality; absence or reduced ovarian blood flow suggests torsion but does not exclude it due to dual ovarian blood supply. Enlarged, edematous ovary with peripheral follicles and free pelvic fluid support the diagnosis ¹.

When ultrasound is inconclusive, cross-sectional imaging such as CT or MRI can help differentiate ovarian torsion from other gynecologic or gastrointestinal causes of pain. CT may show an enlarged ovary with twisted vascular pedicle (the 'whirlpool sign'), deviation of the uterus toward the affected side, and surrounding fat stranding. MRI provides superior soft tissue contrast and can better characterize adnexal masses and confirm torsion by demonstrating twisted vascular pedicle and ovarian edema (Kalish et al., 2007; Dawood et al., 2021).

Risk factors such as ovarian cysts or masses, especially those larger than 5 cm, increase the likelihood of torsion and should raise clinical suspicion ¹.

In summary, differentiation relies on a combination of clinical suspicion based on acute unilateral pain and nausea, targeted ultrasound with Doppler assessment, and, if needed, advanced imaging with CT or MRI to identify characteristic signs of torsion and exclude other causes of acute abdominal pain in women.