Ovarian torsion: diagnostic features on CT and MRI with pathologic correlation

OBJECTIVE: The CT and MRI features of ovarian torsion are illustrated with gross pathologic correlation. Ovarian enlargement with or without an underlying mass is the finding most frequently associated with torsion, but it is nonspecific. A twisted pedicle, although not often detected on imaging, is pathognomonic when seen. Subacute ovarian hemorrhage and abnormal enhancement is usually seen, and both features show characteristic patterns on CT and MRI. Ipsilateral uterine deviation can also be seen. CONCLUSION: Diagnostic pitfalls that may mimic ovarian torsion and observations for discriminating them are discussed.