Torsion, ovarian

Affected individuals generally present with nonspecific symptoms of an acute abdomen. Differential diagnoses based on clinical presentation may include ovarian cyst rupture, haemorrhage, appendicitis or salpingitis. Because ovarian torsion may be a surgical emergency, timely diagnosis is crucial for salvage of the affected ovary. However, clinical, laboratory, and imaging findings are nonspecific, and the diagnosis can only be made definitively by means of exploratory surgery.

Ultrasound is the imaging modality of choice in the evaluation of suspected ovarian torsion. Ultrasound is useful in depicting adnexal pathology and can be utilized with relative ease in the acute patient. However, the sonographic findings are nonspecific. An adnexal mass may be seen, with or without abnormal free fluid in the pelvis. Depending on the duration of torsion, the affected ovary may appear hypoechoic and enlarged, signifying inflammatory oedema. One specific (but not necessarily sensitive) sign is the presence of multiple follicles of uniform size (812 mm in diameter) in the cortical aspect of a unilaterally enlarged ovary in a prepubertal patient, in whom enlarged follicles are not expected because of her prepubertal age. Because of collateral blood supply, demonstration of blood flow by colour Doppler sonography does not exclude ovarian torsion.

CT and MRI findings of ovarian torsion may be seen in the subacute or clinically unsuspected patient (Fig.1). In one case series of 10 patients, the following CT and MRI findings were seen in decreasing order of frequency: