Diagnostic Accuracy of Transvaginal Ultrasonography for Endometriosis According to the International Deep
Ido Mick1, Shay M Freger1, Melissa Marien1
1Department of Obstetrics & Gynecology, McMaster University, Hamilton, Ontario, Canada; and Robinson Research Institute, University of Adelaide, Adelaide, Australia.
Objective:
To evaluate the diagnostic accuracy of transvaginal ultrasonography (TVUS) in detecting deep endometriosis, ovarian endometriosis, and superficial endometriosis using the IDEA (International Deep Endometriosis Analysis) consensus and novel International Terminology definitions for endometriosis phenotypes.
Methods:
This prospective diagnostic accuracy study was conducted at McMaster University from November 2021 to January 2023. Participants included 125 individuals aged 18-50 years with suspected endometriosis who were undergoing TVUS followed by laparoscopic surgery. The index test, TVUS, was performed in accordance with the IDEA consensus, with results compared with laparoscopy and histopathologic findings, which served as the reference standard. Deep endometriosis was defined as endometriosis with any depth of infiltration, and superficial endometriosis was defined as endometriosis without any infiltration beyond the peritoneal surface. Diagnostic accuracy metrics, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value were calculated.
Results:
The study demonstrated high diagnostic accuracy for endometriomas and deep endometriosis with TVUS, achieving a sensitivity of 95.0% for left ovarian endometrioma, 94.9% for right ovarian endometrioma, and sensitivity ranging from 84.3% to 100% for various deep endometriosis sites. Transvaginal ultrasonography showed high specificity for endometriomas (98.9%) and deep endometriosis (range 97.0-100%). However, TVUS showed lower sensitivity for superficial endometriosis (range 4.0-43.5%) but high specificity (99.0-100%) and PPV (90.0-100%). The accuracy of detecting superficial endometriosis improved when cases with ovarian endometriosis, deep endometriosis, and pouch of Douglas obliteration were excluded.
Conclusion:
Transvaginal ultrasonography demonstrates robust diagnostic accuracy for deep endometriosis and ovarian endometriosis, reaffirming its utility as a first-line diagnostic tool in endometriosis management despite changes in definitions of deep endometriosis and superficial endometriosis. However, its sensitivity for superficial endometriosis remains limited, suggesting the need for additional diagnostic techniques or refined ultrasound approaches for accurate detection of superficial endometriosis. The findings support the integration of TVUS in clinical practice while highlighting the need for further advancements in diagnosing superficial endometriosis to mitigate diagnostic delays.
