Retroverted uterus, negative sliding sign
Although not clearly depicted in this clip, deep endometriosis likely is present posterior to the uterus at the level of the internal cervical os, as demonstrated by the irregular, hypoechoic area.
The uterine fundus is being pushed cephalad by the transvaginal ultrasound probe, but the contents posterior to the uterus are not sliding smoothly against the posterior uterine serosa and fundus. Although not clearly depicted in this clip, deep endometriosis likely is present posterior to the uterus at the level of the internal cervical os, as demonstrated by the irregular, hypoechoic area.
For more information: Noninvasive ultrasound diagnosis of endometriosis