OVARIAN TORSION

Ovarian torsion, which is defined the twisting of an ovary with vascular pedicle on its axis which leads to lymphatic, venous and arterial obstruction. It is most commonly seen in women during their reproductive years, because of the increased rate of ovarian masses at the extreme of age. Clinical symptoms, which are left or right quadrant pain, pelvic tenderness, are often nonspecific, hence in most cases it might be difficult to differentiate the torsion from the other causes of lower quadrant pain.(1,2) Since US is noninvasive, cost-effective and accurate with the results, it is the primary modality to evaluate ovarian torsion. The color doppler flow has limited specifity to demonstrate absence of arterial flow in torsion of the adnexa, because the dual blood supply of the ovaries and the symtomps of the ovarian torsion result from venous obstruction which occurs before arterial obstruction.(2) The identificaion of twisted pedicle, the whirlpool sign, is very definitive for the torsion, but it is not commonly seen. The most common finding in the gray-scale US is the enlargement of the ovary with multipl homogeneous peripheral cysts. (2,3) CT and MRI are useful when sonographic findings are ambigous. MRI also can be used to characterize the ovarian mass further and to evaluate preoperative viability of the ovary. Despite the diagnostic criteria for the torsion is not well-defined for CT and MRI, an adnexial mass with ipsilateral deviation of the uterus in a patient with clinical symptoms should be suspicious. They useful when sonographic examination findings is ambigous. (3,4)