Preoperative diagnosis of ovarian tumors with MR imaging: Comparison with transvaginal sonography, positron emission tomography, and histologic findings

Objective. Our study evaluated the diagnostic performance of MR imaging com pared with that of transvaginal sonography and positron emission tomography (PET) in patients with clinically asymptomatic adnexal findings. An additi onal goal was to determine whether the combination of the three methods enh anced their diagnostic accuracy. Subjects and methods. Included in the study were 103 women with suspicious adnexal findings on sonography. Patients underwent transvaginal sonography, MR imaging, and PET within 3 weeks of the initial sonography. For MR imagi ng, axial and sagittal T1-weighted gradient-echo sequences (unenhanced and enhanced) and T2-weighted turbo-spin-echo sequences were acquired. Transvag inal sonography was performed with a 7.5-MHz transducer head. For PET, a mo dern full-ring scanner was used. The results of diagnostic imaging techniqu es were first evaluated separately, and reviewers were blinded to the resul ts of other methods. Finally, a second session resulted in a consensus diag nosis based on the findings of all three methods. Results of histology were considered the gold standard. Results. Histology revealed 12 malignant and 91 benign ovarian tumors. The following data were calculated for MR imaging, transvaginal sonography, PET , and consensus diagnosis: sensitivities, 83%, 92%, 58%, 92%; specificities , 84%, 59%, 78%, 84%; diagnostic accuracies, 83%, 63%, 76%, 85%, respective ly. MR imaging, particularly with contrast-enhanced fat-saturated T1-weight ed sequences, was found to correctly reveal dermoid and endometrial cysts. All three methods had false-negative findings with borderline tumors. Conclusion. Transvaginal sonography is the diagnostic method of choice as a screening technique for ovarian processes. Suspicious findings on transvag inal sonography should be confirmed on MR imaging. If MR imaging confirms a dermoid or endometrial cyst, further diagnostic procedures may be unnecess ary. In all other cases, a surgical evaluation must be considered.