CT prediction of the degree of ovarian torsion

Purpose Torsion angle determines the incidence of necrosis among patients with ovarian torsion. The purpose of this study was to evaluate the association between torsion angle and findings on CT scan. Materials and methods We retrospectively reviewed CT scan findings obtained less than 36 h before surgery for 31 patients with ovarian torsion. Ovarian torsion angles measured intraoperatively ranged from 90° to 1260°. Ovaries with torsion angles less than 360° rarely develop necrosis. Patients were divided into two groups according to torsion angle: <360° (Group A) and ≥360° (Group B). A lesion corresponding to an enlarged fallopian tube and mesovarium containing dilated veins between the uterus and twisted ovary is referred to as a “mass-like swelling”. Results A mass-like swelling occurred more often in Group B ( p < 0.05) and had the highest correlation with torsion angles ≥360°. A mass-like swelling lacking enhancement or a high-density area was significantly different between the groups ( p < 0.05) and was also indicative of torsion angles ≥360°. Conclusion A mass-like swelling alone or with a high-density area or lack of enhancement suggests an ovarian torsion angle ≥360°. The presence of these findings predict ovarian necrosis and may allow ovary-sparing treatment.