Value of ultrasound and magnetic resonance imaging in the preoperative evaluation of suspected ovarian masses

Abstract

Background: The stage of ovarian carcinoma at diagnosis directly affects prognosis. Thus, thorough pretreatment evaluation is basic to the successful management of suspected ovarian masses. Among currently available imaging techniques in characterization of suspected ovarian neoplasms, sonography (US) is indisputedly the primary imaging approach. When US is inconclusive, magnetic resonance imaging (MRI) is generally prefered to computed tomography (CT).

Materials and methods: 93 patients, who on the basis of clinical findings were suspected to have ovarian cancer and who were scheduled for subsequent surgical staging underwent preoperative transvaginal and abdominal ultrasound as well as magnetic resonance imaging in a prospective comparative study. US and MR images were evaluated for their information on the characterization and staging of the ovarian masses.

Results: MRI correctly characterized malignant and benign tumors in 89% of cases versus 85% by ultrasound. The site of the primary tumor was correctly diagnosed in 94% of cases by MRI vs. 90% by ultrasound. For US, the positive predictive value was 85%, the negative predictive value 73% vs. 92% and 89% for MRI. In differentiation of nonadvanced disease from advanced malignancy, US showed a false-positive rate of 0.416 and false-negative rate of 0.258 vs. 0.125 and 0.032 respectively, for MRI.

Conclusion: MRI was superior in diagnosis of malignant ovarian masses though US, too, performed well at lesion detection and characterization. With regard to tumor staging MRI is emerging as a problem-solving modality and may allow more appropriate clinical decisions to be made in selected patients with complex adnexal disease.