The accuracy of transvaginal ultrasound and magnetic resonance imaging for deep urinary tract endometrisis.

The accuracy of transvaginal ultrasound and magnetic resonance imaging for deep urinary tract endometrisis.

Both techniques are useful in predicting deep urinary tract endometriosis, study updated.

Key Points


  • Transvaginal ultrasonography (TVS) and Magnetic resonance imaging (MRI) are useful with specific strong points in diagnosing urinary tract endometriosis.


  • Both techniques provide good accuracy with specific strong points in diagnosing deep urinary endometriosis and are useful first-line methods.

What's done here:

  • A comprehensive literature search was conducted for the meta-analysis to determine the accuracy of TVS and MRI  in diagnosing deep urinary tract endometriosis between 1989-2020.
  • Two researchers evaluated the studies and extract the data using a standardized tool.
  • Meta-analyses was performed and the accuracy, sensitivity, and specificity were calculated. If heterogeneity exists, meta-regression was performed to assess the covariates.

Key Results:

  • Out of 913 studies in the literature, 23 were found eligible and were evaluated.
  • For bladder endometriosis, the overall pooled sensitivities of TVS and MRI were 72% and 68%, and their specificities were 99% and 100% respectively.
  • For urethral endometriosis, the overall pooled sensitivities were 97% and 87% respectively, with the specificities of 100%. 
  • Both techniques are useful first-line diagnostic methods in diagnosing urinary tract endometriosis.
  • In terms of sensitivity, both methods are more accurate for predicting urethral endometriosis than bladder endometriosis.

Lay Summary

The prevalence of urinary tract endometriosis is 19-53% in patients within deep infiltrating endometriosis cases. The bladder and ureteral are the most common sites of the involvement. While preparing a radical surgery for a patient with deep endometriosis, the diagnosis of urinary tract endometriosis is important because the involvement of the bladder or ureters could be clinically asymptomatic. 

Transvaginal ultrasonography (TVS) was the most preferred method until the discovery of Magnetic resonance imaging (MRI), which is known to improve the diagnostic accuracy in women with endometriosis. Several recent meta-analyses have shown that MRI is only slightly superior to TVS in good diagnostic accuracy. To update the knowledge about the accuracy of the imaging techniques for diagnosing urinary tract endometriosis, Zhu and colleagues from the Department of Obstetrics and Gynecology of Peking University, Beijing, China, conducted a meta-analysis. The studies that were written in English with more than 30 patients with clinical suspicion of deep infiltrating endometriosis, and TVS and/or MRI as the index test were included, the gold standard reference being the histological confirmation. Overall 23 studies that were published between 2004 to 2019 were evaluated.

Meta-analyses of TVS and MRI for the diagnosing of urinary tract endometriosis showed that the superiority of MRI  to TVS is not significant. This result confirms the previous studies and supports the role of TVS as a cost-effective first-line technique. It must be emphasized that in all of these studies TVS was performed by an experienced ultrasonographer. Non-professional operators without specific training in urinary tract endometriosis recognition may reduce the diagnostic accuracy of TVS. As far as the cost-effectiveness of the procedures is also important, the authors did not make any specific recommendation concerning the superiority of the techniques in diagnosing deep urinary tract endometriosis.

This study was published in a recent issue of the Journal of Obstetrics and Gynaecology.

Research Source:

transvaginal ultrasonography magnetic resonance imaging meta-analyses urinary tract urethers bladder endometriosis.


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