Comparison between clinical examination, transvaginal sonography and magnetic resonance imaging for the diagnosis of deep endometriosis

Abstract

Background: Deeply infiltrating endometriosis affecting the retrocervical region and the rectosigmoid generally requires surgical treatment. Clinical examination, transvaginal ultrasonography (TVUS) and pelvic magnetic resonance imaging (MRI) are useful in the preoperative diagnosis of the involvement of these sites. The objective of this study was to evaluate the capacity of digital vaginal examination, TVUS and MRI to diagnose rectosigmoid and retrocervical involvement.

Methods: A total of 104 patients with clinically suspected endometriosis were submitted to clinical examination, pelvic MRI and TVUS until 3 months prior to videolaparoscopy and the findings of these methods were matched with histopathological confirmation of endometriosis.

Results: Endometriosis was histologically confirmed in 98 of 104 (94.2%) patients. With respect to the rectosigmoid and retrocervical sites, respectively, digital vaginal examination had a sensitivity of 72 and 68%, specificity of 54 and 46%, positive predictive value (PPV) of 63 and 45%, negative predictive value (NPV) of 64 and 69% and accuracy of 63 and 55%. For TVUS, sensitivity was 98 and 95%, specificity 100 and 98%, PPV 100 and 98%, NPV 98 and 97% and accuracy 99 and 97%. MRI had a sensitivity of 83 and 76%, specificity of 98 and 68%, PPV of 98 and 61%, NPV of 85 and 81% and accuracy of 90 and 71%.

Conclusions: TVUS had better sensitivity, specificity, PPV, NPV and accuracy in cases of deep retrocervical and rectosigmoid endometriosis when compared with MRI and digital vaginal examination, confirming that it is an important preoperative examination for the definition of surgical strategies.