Ultrasound is a reliable first‐lineimaging modality for the assessment of patients with gynaecological concerns.In patients with suspected endometriosis, ultrasound serves three purposes.First, it is used to evaluate the aetiology of the patient's symptoms. Second,it has the potential to map the disease location. Lastly, it can ascertain theextent of disease.
From a clinical perspective, these products of ultrasound may benefit patientsby ensuring a thorough understanding of disease by both the patient, who needsto provide informed consent to treatment options, and the physician, who mayadequately prepare for potentially advanced surgical procedures. In many cases,when deep endometriosis (DE) exists, physicians need to consider referral to anappropriate gynaecologic surgeon with advanced skill. The multidisciplinaryinput of other specialists such as colorectal or urologic surgeons or fertility specialist may also be necessary.
Recently, the International Deep Endometriosis Analysis (IDEA) group publisheda systematic approach to sonographically evaluate the pelvis in patients withsuspected endometriosis. This consensus statement was developed to standardiseanatomical landmarks, nomenclature of disease and the components of anultrasound seeking to identify DE. A four‐step system was introduced, includingroutine evaluation of the uterus and adnexa, evaluation of soft markers such assite‐specific tenderness (SST), assessment of the pouch of Douglas (POD) usingthe ‘sliding sign’ and, finally, assessing the presence of DE nodulescompartmentally throughout the pelvis
The ultrasound: uterus
The orientation (anteverted, retroverted or military) and dimensions inthree orthogonal planes should be recorded. Patients with endometriosis have ahigh likelihood of concurrent adenomyosis and as such, signs of this should besought. In addition, the ‘question mark sign’, signifying a fixedanteverted/retroflexed uterus with the fundus adhered posteriorly to the rectumand/or sigmoid colon can represent adenomyosis and/or endometriosis and shouldbe documented
Theultrasound: adnexa
Includes evaluation of the ovaries and Fallopian tubes. The entire ovariansize should be measured in three orthogonal planes. Any abnormalities should bequantified, measured and documented. The sonographic characteristics of anyovarian abnormality should be described according to terminology published bythe International Ovarian Tumor Analysis (IOTA) group
Ovarian mobility can be judged by applying pressure to the ovaries using the TVprobe. Non‐mobile ovaries are considered a ‘soft marker’ potentially signifyingsuperficial pelvic endometriosis and/or DE. The mobility of the ovaries isassessed against the pelvic side wall laterally, uterus medially, uterosacralligaments (USLs) inferiorly and each other
‘Kissing’ ovaries, an ultrasound diagnosis of ovaries fixed to each other indirectly indicates intra‐abdominal adhesions and possibly underlying DEof the Fallopian tubes and/or bowel.
Hydrosalpinxor hematosalpinx may be identified in endometriosis.
Theultrasound: site‐specific tenderness
SST-‘soft markers’- The key anatomic locations to assess in this component of thescan include the uterus, adnexa, USLs and POD. Currently, the IDEA grouprecommends a scoring system of 0 or 1; 0 for no pain and 1 for pain. However,this test is still limited in that no scoring system has been validated as yet.
Theultrasound: Sliding sign
The test is considered positive when the uterus and cervix move independently(i.e. slide) along the anterior rectum and sigmoid . Clinically and surgically,this is reassuring for a non‐obliterated POD. Conversely, if the uterus andcervix move in unison with the anterior rectum and sigmoid, the test isnegative and the POD is thought to be obliterated.
SchematicDrawing Demonstrating How to Elicit the ‘Sliding Sign’ in an Anteverted Uterus(a) and Retroverted Uterus
Theultrasound: anterior and the posterior compartment
Lesions may appear as hypoechoic linear or spherical lesions, with or withoutregular contours . The uterovesical region should be examined for tethering tothe uterus (i.e. obliteration of the space). The concept of the ‘sliding sign’can be applied here as well. The operator should hold the TV probe in theanterior fornix with one hand and the other hand should be placed over thesuprapubic region. By balloting the uterus between the probe and hand, theoperator can judge whether the posterior bladder slides freely over theanterior uterine wall,
When the bladder and uterus move together, the operator should document anegative ‘sliding sign’, representing an obliterated space. Anindependently moving bladder from the uterus represents a positive ‘slidingsign’.
The posterior compartment sites include USLs, posterior vaginal fornix,rectovaginal septum (RVS), anterior rectum, anterior rectosigmoid junction andsigmoid colon. Done by gently placing the TV probe in the posterior vaginalfornix
Schematicand Ultrasound Images Demonstrating an Isolated RVS Nodule. Note theHyperechoic Nature of the RVS (Red Star) and Adjacent Hypoechoic Layers ofVagina (Yellow Star) and Rectal Wall Muscularis (Green Circle).
Schematic and Ultrasound Image Demonstrating the Location of DeepEndometriosis (DE) in the Right Uterosacral Ligament in Transverse View (WithinGreen Circle)
