Ovarian (or adnexal) torsion is a rare but serious gynecological condition that requires accurate evaluation and appropriate surgical intervention. Patients typically present with intense lower abdominal pain, sometimes accompanied by nausea or vomiting. However, these symptoms can have many causes and do not automatically point to torsion.
Ultrasound is a critical first-line diagnostic tool for evaluating ovarian function and pinpointing signs of ovarian torsion. A "whirlpool sign" identified with color Doppler ultrasound is a strong indicator of ovarian or adnexal torsion and can help guide the next steps for treatment.
What Causes Ovarian Torsion?
Adnexal torsion is often caused by an ovarian mass or cyst that leads to rotation of the adnexa, or the vascular pedicle. A twisted pedicle can ultimately lead to ovarian necrosis and subsequent loss of the ovary and fallopian tube if it is not treated quickly. An ultrasound of a patient with abdominal pain might reveal abnormally positioned ovaries, masses or ovarian enlargement. The whirlpool sign is a more definitive indicator of torsion.
Understanding the Whirlpool Sign on Ultrasound
This distinctive sign can be seen on ultrasound by moving the probe along the axis of the suspected torsion. It appears as a clockwise or counterclockwise wrapping of vessels around the central axis. A whirlpool can be visualized using color Doppler or greyscale but is best identified by a highly trained sonographer.
The circular motion visible on the ultrasound image represents the twisted pedicle itself and provides a compelling reason to move forward with a diagnosis and surgical intervention. One study in Ultrasound in Obstetrics and Gynecology confirmed that the presence of the whirlpool sign in patients suspected of having torsion led to 90 percent confirmation of torsion with laparoscopy.
Evaluating Ovarian Torsion With Color Doppler Ultrasound
Besides demonstrating the whirlpool sign, color Doppler ultrasound provides additional information for surgery. Surgery is the preferred treatment for torsion; in some cases the ovary can be untwisted, but in other cases it may be necessary to remove the ovary and fallopian tube. A study from the Journal of Human Reproductive Sciences speculated that a whirlpool sign could indicate an ovary that is not yet necrotic and can be saved.
Spotting a whirlpool on color Doppler provides the most definitive sign of ovarian torsion. Using ultrasound with a Doppler tool like Radiantflow provides high sensitivity and visualizes blood flow in tiny structures. Radiantflow produces a high image quality with more specificity, giving you more confidence in potential surgical interventions.
Power Doppler also assists with diagnosis and treatment planning by detecting areas of restricted blood flow and low-flow vessels. These imaging tools give you more details of ovarian masses, necrosis and the viability of fertility-sparing surgery.
Every advance in ultrasound technology makes it more reliable as a diagnostic tool in gynecology. New imaging options and enhanced training can provide a clearer picture of adnexal torsion and help your patients get the best treatment possible.
