While ultrasound has clear benefits, its limitations should be acknowledged. Most importantly, ultrasound is operator-dependent. The operator must know how to perform the techniques described and appropriately capture images and video clips. Today, no governing body yet requires that sonographers assess for direct visualization of DE or dynamic signs of pelvic adhesions. Similarly, radiologists and sonologists are not yet consistently educated on how to interpret and report on advanced pelvic ultrasound for endometriosis. Broadly, this limits its accessibility outside specialized tertiary care centers. For both the operators and interpreters of ultrasonography, the didactic and practical curriculum needs updating.
In addition, TVS has a maximum penetration depth, limiting the ability to diagnose lesions above the pelvic brim. Anatomical areas including the small bowel, cecum, appendix, and diaphragm are not yet assessable for DE on TVS. Magnetic resonance imaging may play a role in evaluating these areas but is beyond the scope of this paper.
Finally, the diagnostic performance of TVS is not perfect. Historically, TVS has been less accurate for anatomic areas such as the USLs and parametrium, when there may be ureteral involvement. It is hoped that the IDEA consensus opinion will improve diagnostic performance by standardizing the approach to TVS and unifying nomenclature. Research that is ongoing on how to refine techniques and advance ultrasound technology should continue to improve the ability of TVS to capture all phenotypes of endometriosis.
This instructional guide has outlined all aspects of ultrasound evaluation in patients with suspected endometriosis. Our approach is guided by the IDEA group consensus statement14 and our personal experience. We understand that ultrasound is not the only method for evaluating endometriosis and under the umbrella of ultrasound evaluation, there may be different techniques and procedures.
Regardless of the approach, we recommend a systematic one that is performed and interpreted by experts. Patients with endometriosis have experienced use of inadequate diagnostic tools for far too long (and still do). It is important that if we are making conclusions based on imaging tools, those tools are used properly with a clear understanding of benefits and limitations. In our unit, a negative ultrasound does not rule out SE (though it does rule out DE, OEs, and rectouterine pouch obliteration). This means there may still be a role for laparoscopy to diagnose patients with SE, but we only use it when patients prefer surgery or their condition requires it. Overall, we are getting closer and closer to being able to offer patients a way to visualize their disease noninvasively and to rule out the disease. Ongoing research, we hope, will continue to improve what is already a highly useful clinical tool.
- Giudice LC. Endometriosis. N Engl J Med. 2010;362:2389-2398.
- Adamson GD, Kennedy S, Hummelshoj L. Creating solutions in endometriosis: Global collaboration through the World Endometriosis Research Foundation. J Endometr. 2010;2:3-6.
- Leonardi M, Singh SS, Murji A, et al. Deep endometriosis: a diagnostic dilemma with significant surgical consequences. J Obstet Gynaecol Canada. 2018;40:1198-1203.
- Leyland N, Casper R, Laberge P, et al. Endometriosis: diagnosis and management. J Obstet Gynaecol Canada. 2010;32:S1-S28.
- American College of Obstetricians and Gynecologists. Practice Bulletin No. 114: Management of Endometriosis. Obstet Gynecol. 2010;116:223-236.
- Agarwal SK, Chapron C, Giudice LC, et al. Clinical diagnosis of endometriosis: a call to action. Am J Obstet Gynecol. 2019;220:354.e1-354.e12.
- Kho KA, Shields JK. Diagnosis and management of primary dysmenorrhea. JAMA. 2019;344:1-2.
- Benacerraf BR, Groszmann Y. Sonography should be the first imaging examination done to evaluate patients with suspected endometriosis. J Ultrasound Med. 2012;31:651-653.
- Somigliana E, Vercellini P, Vigano’ P, Benaglia L, Crosignani PG, Fedele L. Non-invasive diagnosis of endometriosis: The goal or own goal? Hum Reprod. 2010;25:1863-1868.
- Singh SS, Suen MWH. Surgery for endometriosis: beyond medical therapies. Fertil Steril. 2017;107:549-554.
- Menakaya UA, Rombauts L, Johnson NP. Diagnostic laparoscopy in pre-surgical planning for higher stage endometriosis: Is it still relevant? Aust New Zeal J Obstet Gynaecol. 2016;56:518-522.
- Nisenblat V, Bossuyt PMM, Farquhar C, Johnson N, Hull ML. Imaging modalities for the non-invasive diagnosis of endometriosis. Cochrane Database Syst Rev. 2016:Art. No.: CD009591. DOI: 10.1002/14651858.CD009591.
- AIUM Practice Guideline for the Performance of Ultrasound of the Female Pelvis. J Ultrasound Med. 2014;33:1122-1130.
- Guerriero S, Condous G, van den Bosch T, et al. Systematic approach to sonographic evaluation of the pelvis in women with suspected endometriosis, including terms, definitions and measurements: a consensus opinion from the International Deep Endometriosis Analysis (IDEA) group. Ultrasound Obstet Gynecol. 2016;48:318-332.
- Reid S, Lu C, Casikar I, et al. Prediction of pouch of Douglas obliteration in women with suspected endometriosis using a new real-time dynamic transvaginal ultrasound technique: the sliding sign. Ultrasound Obstet Gynecol. 2013;41:685-691.
- Gerges B, Lu C, Reid S, Chou D, Chang T, Condous G. Sonographic evaluation of immobility of normal and endometriotic ovary in detection of deep endometriosis. Ultrasound Obstet Gynecol. 2017;49:793-798.
- Tompsett J, Leonardi M, Gerges B, et al. Ultrasound-based endometriosis staging system: validation study to predict complexity of laparoscopic surgery. J Minim Invasive Gynecol. 2019;26:477-483.
- Collins BG, Ankola A, Gola S, McGillen KL. Transvaginal US of endometriosis: looking beyond the endometrioma with a dedicated protocol. RadioGraphics. 2019;39:1549-1568.
- National Institute for Health and Care Excellent. Endometriosis: Diagnosis and Management.; 2017. nice.org.uk/guidance/ng73.
- Leonardi M, Condous G. How to perform an ultrasound to diagnose endometriosis. Australas J Ultrasound Med. 2018;21:61-69.
- Young SW, Groszmann Y, Dahiya N, et al. Sonographer-acquired ultrasound protocol for deep endometriosis. Abdom Radiol. 2019.
- Timmerman D, Valentin L, Bourne TH, Collins WP, Verrelst H, Vergote I. Terms, definitions and measurements to describe the sonographic features of adnexal tumors: a consensus opinion from the International Ovarian Tumor Analysis (IOTA) group. Ultrasound Obstet Gynecol. 2000;16:500-505.
- Van Holsbeke C, Van Calster B, Guerriero S, et al. Endometriomas: Their ultrasound characteristics. Ultrasound Obstet Gynecol. 2010;35:730-740.
- Redwine DB. Ovarian endometriosis: A marker for more extensive pelvic and intestinal disease. Fertil Steril. 1999;72:310-315.
- Exacoustos C, De Felice G, Pizzo A, et al. Isolated ovarian endometrioma: a history between myth and reality. J Minim Invasive Gynecol. 2018;25:884-891.
- American Society for Reproductive Medicine. Revised American Society for Reproductive Medicine classification of endometriosis: 1996 American Society for Reproductive Medicine. Fertil Steril. 1997;67:817-821.
- Adamson GD, Pasta DJ. Endometriosis fertility index: the new, validated endometriosis staging system. Fertil Steril. 2010;94:1609-1615.
- Chapron C, Fauconnier A, Vieira M, et al. Anatomical distribution of deeply infiltrating endometriosis: Surgical improblications and proposition for a classification. Hum Reprod. 2003;18:157-161.
- Khan MAS, Ang CW, Hakeem AR, Scott N, Saunders RN, Botterill I. The impact of tumour distance from the anal verge on clinical management and outcomes in patients having a curative resection for rectal cancer. J Gastrointest Surg. 2017;21:2056-2065.
- Leonardi M, Condous G. A pictorial guide to the ultrasound identification and assessment of uterosacral ligaments in women with potential endometriosis. Australas J Ultrasound Med. 2019;22:157-164.
- Leonardi M, Martins WP, Espada M, Arianayagam M, Condous G. A proposed technique to visualize and classify uterosacral ligament deep endometriosis with and without infiltration into the parametrium or torus uterinus. Ultrasound Obstet Gynecol. April 2019:uog.20300.
- Bean E, Naftalin J, Jurkovic D. How to assess the ureters during pelvic ultrasound. Ultrasound Obstet Gynecol. 2018.
- Aas-Eng K, Salama M, Sevelda U, Ruesch C, Nemeth Z, Hudelist G. Learning curve for detection of the distal part of ureters by transvaginal sonography (TVS): a feasibility study. Ultrasound Obstet Gynecol. June 2019.
- Khong SY, Bignardi T, Luscombe G, Lam A. Is pouch of Douglas obliteration a marker of bowel endometriosis? J Minim Invasive Gynecol. 2011;18:333-337.
- Robinson AJ, Rombauts L, Ades A, Leong K, Paul E, Piessens S. Poor sensitivity of transvaginal ultrasound markers in diagnosis of superficial endometriosis of the uterosacral ligaments. J Endometr Pelvic Pain Disord. 2018;10:10-17.
- Reid S, Leonardi M, Lu C, Condous G. The association between ultrasound-based ‘soft markers’ and endometriosis type/location: A prospective observational study. Eur J Obstet Gynecol Reprod Biol. 2019;234:171-178.
- Chowdary P, Stone K, Ma T, et al. Multicentre retrospective study to assess diagnostic accuracy of ultrasound for superficial endometriosis—Are we any closer? Aust New Zeal J Obstet Gynaecol. 2019;59:279-284.
- Leonardi M, Espada M, Lu C, Stamatopoulos N, Condous G. A novel ultrasound technique called saline infusion sonoPODography to visualize and understand the pouch of Douglas and posterior compartment contents: A Feasibility Study. J Ultrasound Med. 2019;38:3301-3309.