What imaging modalities are recommended for confirming a diagnosis of ovarian torsion in primary care?

In primary care, the recommended imaging modality to confirm a diagnosis of ovarian torsion is a transvaginal ultrasound scan, often supplemented by a transabdominal ultrasound if needed. This approach allows visualization of the adnexa to detect signs of torsion such as an enlarged ovary, peripheral follicles, and absence or reduction of blood flow on Doppler imaging, which are key indicators of ovarian torsion.

Ultrasound is the first-line imaging because it is non-invasive, readily available in primary care or via urgent referral, and effective in assessing ovarian morphology and vascularity. If ultrasound findings are inconclusive and clinical suspicion remains high, urgent referral to secondary care for further imaging or surgical assessment is warranted.

While CT and MRI can provide additional information in complex cases or when ultrasound is inconclusive, they are not routinely recommended as first-line imaging in primary care due to limited availability and lower sensitivity for ovarian torsion compared to ultrasound.

Therefore, primary care clinicians should arrange an urgent transvaginal ultrasound scan when ovarian torsion is suspected clinically, and refer promptly if imaging or clinical findings suggest torsion or if the diagnosis remains uncertain.

This recommendation aligns with UK guidelines emphasizing ultrasound as the initial imaging modality for adnexal pathology and is supported by literature highlighting the characteristic ultrasound features of ovarian torsion and the limited role of CT and MRI in initial diagnosis (Kalish et al., 2007) ¹.