A Plea to Improve and Adopt Ultrasound for Endometriosis
By Dr Mathew Leonardi and Prof. George Condous
In general, patients want an explanation for their symptoms. They want a diagnosis. Of course, in most cases, patients would prefer the reassurance of a disease’s absence. This is why they undergo imaging investigations. This is why healthcare providers refer patients for ultrasounds. For those with pelvic pain, dysmenorrhea, dyspareunia, and infertility, they are looking for clarity regarding possible endometriosis. The chronic nature of the disease makes this patient population particularly desperate for answers.
But what is the point of sending someone for a transvaginal ultrasound is you really don’t believe endometriosis can be seen on ultrasound? Unpublished results of a survey our team completed suggest most obstetrician-gynecologist (OB/GYN) specialists still don’t believe ultrasound can see endometriosis, with the exception of ovarian endometriomas. So sure, in their minds, a scan can give the patients and healthcare providers some clarity. But endometriomas are certainly not present in the majority of patients with endometriosis. Does that leave all superficial and deep endometriosis to be diagnosed at laparoscopy, an invasive investigative (and possibly therapeutic) tool with real risks1?
The answer is no.
Figure 1. Transvaginal ultrasound showing an area of vaginal deep endometriosis.
For years, there has been plenty of research on the diagnosis of deep endometriosis using ultrasound. Nisenblat et al. published a systematic review and meta-analysis on this subject, demonstrating traditional transvaginal ultrasound has a sensitivity of 79% and specificity of 94% for deep endometriosis2. That means roughly 8/10 patients with deep endometriosis can be detected in a non-invasive fashion and only 6/100 patients will be falsely diagnosed with deep endometriosis that is not seen at surgery. In addition, many of the authors whose work contributed to this meta-analysis are still working hard to further refine this, by adapting techniques and performing large-multicenter work following the publication of the consensus statement on ultrasound for endometriosis3. Our team is investigating the possibility of visualizing superficial endometriosis on transvaginal ultrasound4.
Figure 2. Bladder deep endometriosis.
With these numbers in mind, shouldn’t GPs and OB/GYNs be demanding sonographic evaluation of both ovarian endometriomas and deep endometriosis in all patients with concerns for endometriosis? Shouldn’t this be especially important if someone is planned for surgery to prepare for surgery5?
Figure 3. Bladder wall deep endometriosis.
Depending on the region in the world, sonography can be the domain of radiologists or OB/GYNs or some combination of both6. It is not just the responsibility of GPs and OB/GYNs to request thorough sonographic evaluation of endometriosis, but those responsible for performing and interpreting ultrasound must also stay up-to-date, providing evidence-based care. For those involved in gynecological scanning, the learning curve for bowel deep endometriosis and pouch of Douglas obliteration is estimated at 40 supervised scans7. Guerriero et al. also propose it is possible to learn the skills predominantly offline8. If it is not possible to obtain supervision to learn, there are resources that can assist in learning.
Figure 4. Negative sliding sign and bowel deep endometriosis.
Figure 5. Normal bowel.
Figure 6. Uterosacral ligament deep endometriosis with ovarian fixation and endometrioma.
Of course, nothing beats practice, but the technique, instruction on visualizing anatomical structures, and guidance on what and how to report findings can be found at the following resources:
- 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) group3
- How to perform an ultrasound to diagnose endometriosis9
- A pictorial guide to the ultrasound identification and assessment of uterosacral ligaments in women with potential endometriosis10
- How to Perform Ultrasonography in Endometriosis (Textbook)
The delay in diagnosis of endometriosis ranges from 7-11 years11,12. This is simply unacceptable when it is possible to see endometriosis on ultrasound. Ultrasound is usually the first investigation patients undergo when they present to their healthcare provider. We, the sonologists, radiologists, and sonographers, can change the course of patients with endometriosis by giving them answers.
We owe it to our patients to look. If we don’t even try, we’ll never see what is right there in front of us.
Dr Mathew Leonardi is a Canadian Gynaecologist currently based in Nepean Hospital, The University of Sydney, Australia.
He has a particular interest in endometriosis. For more information on his research interests click here. You can follow him on Twitter.
Professor George Condous is an Associate Professor in Obstetrics, Gynaecology and Neonatology in Nepean Hospital, The University of Sydney, Australia.
He has a particular interest in advanced gynaecological ultrasound and laparascopic surgery. For more information on his research interests click here. You can follow him on Twitter.
- Singh SS, Suen MWH. Surgery for endometriosis: beyond medical therapies. Fertil Steril. 2017;107(3):549–54.
- Nisenblat V, Bossuyt PMM, Farquhar C, Johnson N, Hull ML. Imaging modalities for the non-invasive diagnosis of endometriosis. Cochrane Database Syst Rev. 2016;(2):Art. No.: CD009591. DOI: 10.1002/14651858.CD009591.
- Guerriero S, Condous G, van den Bosch T, Valentin L, Leone FPG, Van Schoubroeck D, 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(3):318–32.
- 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. https://doi.org/10.1002/jum.15022.
- Leonardi M, Singh SS, Murji A, Satkunaratnam A, Atri M, Reid S, et al. Deep Endometriosis: A Diagnostic Dilemma With Significant Surgical Consequences. J Obstet Gynaecol Canada. 2018;40(9):1198–203.
- Leonardi M, Murji A, D’Souza R. Ultrasound curricula in obstetrics and gynecology training programs. Ultrasound Obstet Gynecol. 2018;52(2):147–50.
- Tammaa A, Fritzer N, Strunk G, Krell A, Salzer H, Hudelist G. Learning curve for the detection of pouch of Douglas obliteration and deep infiltrating endometriosis of the rectum. Hum Reprod. 2014;29(6):1199–204.
- Guerriero S, Pascual MA, Ajossa S, Rodriguez I, Zajicek M, Rolla M, et al. Learning curve for the ultrasonographic diagnosis of deep endometriosis using a structured off-line training program. Ultrasound Obstet Gynecol 2018. https://doi.org/10.1002/uog.20176.
- Leonardi M, Condous G. How to perform an ultrasound to diagnose endometriosis. Australas J Ultrasound Med. 2018 May;21(2):61–9.
- 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. http://doi.org/10.1002/ajum.12178
- Hudelist G, Fritzer N, Thomas A, Niehues C, Oppelt P, Haas D, et al. Diagnostic delay for endometriosis in Austria and Germany: Causes and possible consequences. Hum Reprod. 2012 Dec 1;27(12):3412–6.
- Hadfield R, Mardon H, Barlow D, Kennedy S. Delay in the diagnosis of endometriosis: a survey of women from the USA and the UK. Hum Reprod. 1996;11(4):878–80.