Pelvic Ultrasound for Endometriosis:

The main diagnostic problems for endometriosis are firstly, the detection of the disease, especially in the absence of ovarian endometriotic cyst; and secondly, the evaluation of the extent of the disease in the pelvis. Transvaginal ultrasonography (TVS) has been proposed as the first line-line imaging technique because of its ease of availability, allowing extensive exploration of the pelvis. The ‘typical’ endometrioma is a unilocular cyst with homogeneous low-level echogenicity (ground glass echogenicity) of the cyst fluid. The use of color Doppler helps to avoid classifying malignancies as endometriomas defining the presence or not of flow in papillations. The real-time dynamic TVS examination of adhesions and pouch of Douglas (POD) obliteration, using the sliding sign technique, seems to be useful in the identification of women at increased risk for bowel endometriosis. Utilizing TVS, an accurate assessment of the vagina, particularly the areas of the posterior and lateral vaginal fornixes, the retrocervical area with torus uterinum and uterosacral ligaments and the rectovaginal septum should be performed. The slightly filled bladder permits evaluation of the structure of the bladder walls and the presence of endometriotic nodules which appear as hypoechoic linear or spherical lesions bulging towards the lumen, involving the serosa, muscularis and/or (sub)mucosa of the bladder. Deep nodes of the rectum appear as hypoechoic lesions, linear or nodular retroperitoneal thickening with irregular borders, and a few vessels at power Doppler evaluation, penetrating into the intestinal wall distorting its normal structure. 2D TVS typical myometrial features and 3D evaluation of the junctional zone seem important to diagnose adenomyosis. Although in the published literature, the sensitivity and specificity of TVS in the prediction of DIE and adenomyosis is high, their assessment by TVS is difficult and requires great expertise.