A hypoechoic deep endometriosis nodule is noted within the hyperechoic uterosacral ligament.
In this case, the rectouterine pouch is partially obliterated on the side of the nodule, with tethering of the bowel. It is possible to appreciate the uterus is being tethered posteriorly toward the nodule.
For more information: Noninvasive ultrasound diagnosis of endometriosis