Doppler flow findings not always diagnostic of ovarian torsion

The study was conducted by Gilat L. Grunau, Department of Radiology, Vancouver General Hospital, Vancouver, BC, and colleagues to assess sensitivity and specificity of ultrasound diagnosis of ovarian torsion and to analyze the factors contributing to correct and incorrect diagnosis.

Ovarian torsion is defined as the partial or complete rotation of the ovarian vascular pedicle that causes obstruction to arterial inflow and venous outflow. It is usually associated with a cyst or tumor, which is typically benign; the most common is mature cystic teratoma.

Doppler imaging does not allow the exclusion of torsion but instead suggests that the ovary may be viable, especially if the flow is present centrally. The absence of flow in the twisted vascular pedicle may indicate that the ovary is not viable.

For the study, all women presenting with abdominal pain and admitted for urgent/emergent surgery to the gynecology service at a major teaching hospital between September 2010 and August 2015 were reviewed. Of those, 55 cases of surgically proven ovarian torsion and 48 control cases were selected. Ultrasound reports were reviewed and analyzed.

Sixty-one percent of right ovarian torsion case and 27% of left ovarian torsion cases had normal Doppler flow. Presence of ovarian cysts was significantly associated with torsion. The sensitivity of ultrasound was 70% and specificity was 87%.

"While ultrasound can be used to support a diagnosis of ovarian torsion, it is a clinical diagnosis that requires integration of many factors, especially patient presentation and exclusion of other non-gynecological pathologies. Doppler flow is not a useful variable to diagnose or exclude ovarian torsion and we recommend it should not be used to exclude a diagnosis of ovarian torsion," concluded the authors.