Adnexal masses: comparison of specificity of endovaginal US and pelvic MR imaging

In a prospective study, 32 women with suspected pelvic masses at physical examination underwent both endovaginal ultrasound (US) and magnetic resonance (MR) imaging to compare their ability in diagnosis of adnexal masses. Criteria for the diagnosis of various types of adnexal masses with MR imaging and endovaginal US were prospectively defined, and the ability of either modality to allow a specific diagnosis was assessed. For each modality, measures of sensitivity, specificity, and accuracy were obtained. Results indicated higher diagnostic capability of endovaginal US for simple cysts (five of five), hemorrhagic cysts (eight of nine), endometriomas (nine of 14), and ovarian carcinomas (three of three). MR imaging demonstrated higher diagnostic capability for dermoids (three of three). MR imaging and endovaginal US showed equal diagnostic capability for pedunculated fibroids (two of two). For all masses, observers, and observations, the overall sensitivity of endovaginal US was 76% versus 49% for MR imaging, and the overall accuracy of endovaginal US was 83% versus 70% for MR imaging. The authors suggest that endovaginal US is a better modality than MR imaging for the assessment of suspected pelvic masses.