Society of Radiologists in Ultrasound Consensus on Routine Pelvic US for Endometriosis

Abstract

Endometriosis is a prevalent and potentially debilitating condition that mostly affects individuals of reproductive age, and often has a substantial diagnostic delay. US is usually the first-line imaging modality used when patients report chronic pelvic pain or have issues of infertility, both common symptoms of endometriosis. Other than the visualization of an endometrioma, sonologists frequently do not appreciate endometriosis on routine transvaginal US images. Given a substantial body of literature describing techniques to depict endometriosis at US, the Society of Radiologists in Ultrasound convened a multidisciplinary panel of experts to make recommendations aimed at improving the screening process for endometriosis. The panel was composed of experts in the imaging and management of endometriosis, including radiologists, sonographers, gynecologists, reproductive endocrinologists, and minimally invasive gynecologic surgeons. A comprehensive literature review combined with a modified Delphi technique achieved a consensus. This statement defines the targeted screening population, describes techniques for augmenting pelvic US, establishes direct and indirect observations for endometriosis at US, creates an observational grading and reporting system, and makes recommendations for additional imaging and patient management. The panel recommends transvaginal US of the posterior compartment, observation of the relative positioning of the uterus and ovaries, and the uterine sliding sign maneuver to improve the detection of endometriosis. These additional techniques can be performed in 5 minutes or less and could ultimately decrease the delay of an endometriosis diagnosis in at-risk patients.

Graphical abstract

Figure 1:

Transvaginal US images show the posterior compartment in a 25-year-old patient with dysmenorrhea, on the retrocervical field of view (area of interest outlined in yellow), 4–5-cm deep to the cervix. Longitudinal (A) and transverse (B) views. The transducer is in the anterior fornix. Longitudinal and transverse sweeps were acquired to include these areas.

Figure 2:

Illustration shows how to position the transvaginal sonography transducer based on uterine position and uterosacral ligament (USL) anatomy variations (light gray band). The relative relationship between the transducer, USLs, and cervicouterine junction is demonstrated for (A) anteverted uterus, anterior fornix transducer position; (B) anteverted uterus, posterior fornix transducer position; (C) retroverted uterus, posterior fornix transducer position; and (D) anteflexed/retroverted uterus, anterior fornix transducer position. Reprinted, with permission, from reference .

Figure 3:

Transvaginal US in normal right and left uterosacral ligaments (USL) in a 32-year-old patient with chronic pelvic pain and echogenic bands insert near the posterior cervicouterine junction (arrows, A and B). Transverse oblique images show the (A) right and (B) left anterolateral fornices.

Figure 4:

Transvaginal US in a 41-year-old patient with chronic pelvic pain and dyschezia shows the “question mark sign” uterine configuration. Longitudinal view shows an abnormal uterine configuration in which the uterus is sharply retroflexed because of deep endometriosis that is tethering the posterior cervix to the uterine corpus. This observation is usually identified by abnormal endometrial axis with sharp retroflection of the uterine fundus (dashed blue line) and constitutes a category B (ie, indirect endometriosis) observation.

Figure 5:

Transvaginal US through the posterior fornix in a 43-year-old patient with deep dyspareunia. Serosal adhesions to the adjacent rectum are shown (curved blue arrows). (A) Longitudinal and (B) transverse views show kissing ovaries without endometriomas, a category B (indirect endometriosis) observation. Deep endometriosis of the torus uterinus and posterior uterine serosa is shown (yellow arrows, A and B), a category A (direct endometriosis) observation. L = left, R = right.

Figure 6:

Illustration shows the uterine sliding maneuver, posterior fornix transducer position, anteverted uterus (A) and retroflexed uterus (B). Adapted, with permission, from reference .

Figure 7:

Transvaginal longitudinal US scan in a 31-year-old patient with deep dyspareunia shows an endometrioma with homogeneous low-level (ground glass) echoes (white arrows) and fluid-fluid level (black arrows). Sepia inset in transverse view shows similar observations, a category A (direct endometriosis) observation. Adapted, with permission, from reference .

Figure 8:

(A–C) Transvaginal US images in three reproductive-age individuals (a 34-year-old, 41-year-old, and 37-year-old patient), all presenting with chronic pelvic pain, demonstrate deep endometriosis of the outer uterine serosa (yellow outline) in retroflexed uteri, which is a category A (direct endometriosis) observation. Images were obtained with the (A) transducer in the posterior fornix in longitudinal view, (B) transducer in the anterior fornix in longitudinal view, and (C) transducer in the posterior fornix in transverse view.

Figure 9:

Transvaginal US posterior compartment deep endometriosis (DE) image gallery of reproductive age individuals (19–48 years) with chronic pelvic pain, deep dyspareunia, dyschezia, dysmenorrhea, or infertility demonstrates the spectrum of common DE observations with schematics and color legend. US images in columns A (Ultrasound Image A) and B (Ultrasound Image B) are examples of similar observations in multiple patients. Anteversion and retroversion refer to uterine position. AF = anterior fornix transducer position, CDS = cul-de-sac, PF = posterior fornix transducer position, Long = longitudinal view, rans = Transverse view,.USL = uterosacral ligament.

Figure 10:

Laparoscopic view illustrations of common posterior compartment deep endometriosis (DE) and superficial endometriosis patterns. (A) Unilateral DE in right uterosacral ligament (USL)/torus uterinus. (B) Bilateral USL/torus uterinus DE. (C) Left USL and rectal DE with thickening and retraction of rectal wall toward the torus uterinus. (D) Bilateral USL and torus uterinus DE. Reprinted, with permission, from reference .

Figure 11:

Transvaginal US images of bladder endometriosis in a 31-year-old patient with dysuria shows a midechogenicity nodule (yellow outline) extending from vesicouterine space into the detrusor muscle, longitudinal (A) and transverse (B). Three-dimensional US virtual cystoscopic view is shown (inset, arrows). This is a category A (direct endometriosis) observation.

Figure 12:

Transvaginal US shows deep endometriosis (DE) nodules (N) in the rectosigmoid colon. (A) Image in a 31-year-old patient with dyschezia shows an elliptical DE with tapering ends (arrows), longitudinal posterior fornix. (B) Transverse image of nodule in A, posterior fornix. (C) Image in a 27-year-old patient with chronic pelvic pain shows an Ω-shaped DE nodule in midrectum, longitudinal posterior fornix (arrows). (D) Image in a 33-year-old patient with deep dyspareunia shows a C-shaped nodule in midrectum, longitudinal anterior fornix (arrows). (E) Image in a 40-year-old patient with chronic pelvic pain shows tandem nodules of rectosigmoid colon with tapering ends (arrows), longitudinal posterior fornix. These are category A (ie, direct endometriosis) observations.