Pressure is being applied to the uterus by the ultrasound operator’s non-scanning hand, but the contents posterior to the uterus are not sliding smoothly against the posterior uterine serosa. In this case, there is a fixed ovary posteriorly and subtle hypoechoic nodule posterior to the uterus at the level of the internal cervical os, suggesting of deep endometriosis of the torus uterinus. 

Noninvasive ultrasound diagnosis of endometriosis

In this case, there is a fixed ovary posteriorly and subtle hypoechoic nodule posterior to the uterus at the level of the internal cervical os, suggesting of deep endometriosis of the torus uterinus.