Transrectal pelvic US also allows for accurate measurements from the caudal margin of an endometriotic lesion to the anal verge, which is important for surgical planning in the setting of low-lying lesions that may require a diverting ostomy. These studies are limited by a narrow field-of-view that allows for evaluation of the rectosigmoid colon but cannot evaluate more proximal structures [40,99,100]. US Pelvis Transvaginal TVUS can be used to evaluate rectosigmoid endometriosis but cannot be used to evaluate for lesions proximal to the rectosigmoid junction, which is beyond the field-of-view for a transvaginal probe. Literature surrounding the use of TVUS for the evaluation of rectosigmoid endometriosis has exclusively evaluated protocols that include scanning maneuvers beyond what is included in a routine TVUS as defined by the ACR Practice Parameters. TVUS performed with added maneuvers including scanning with probe in the posterior vaginal fornix and the sliding sign has been shown to be a reliable predictor of bowel endometriosis [101-104]. These protocols can also be used for surgical planning when the lesion length, circumferential extent, distance to the anal verge, and muscular involvement are reported [105-107]. When specialist-performed DE TVUS is used, the accuracy of surgical planning measurements is similar to MRI [108]. A study comparing DE TVUS performed by a trained versus untrained operator showed the modality predicted bowel endometriosis when performed by the trained operator but not by the untrained operator [109]. Variant 4: Adult. Established postoperative endometriosis diagnosis. New or ongoing symptoms of endometriosis. Follow-up imaging. CT Pelvis With IV Contrast There is no relevant literature to support the use of pelvic CT for patients with an endometriosis diagnosis established by surgery with new or ongoing symptoms. CT with IV contrast could help identify and characterize other etiologies of pelvic pain.
Endometriosis. Transrectal pelvic US also allows for accurate measurements from the caudal margin of an endometriotic lesion to the anal verge, which is important for surgical planning in the setting of low-lying lesions that may require a diverting ostomy. These studies are limited by a narrow field-of-view that allows for evaluation of the rectosigmoid colon but cannot evaluate more proximal structures [40,99,100]. US Pelvis Transvaginal TVUS can be used to evaluate rectosigmoid endometriosis but cannot be used to evaluate for lesions proximal to the rectosigmoid junction, which is beyond the field-of-view for a transvaginal probe. Literature surrounding the use of TVUS for the evaluation of rectosigmoid endometriosis has exclusively evaluated protocols that include scanning maneuvers beyond what is included in a routine TVUS as defined by the ACR Practice Parameters. TVUS performed with added maneuvers including scanning with probe in the posterior vaginal fornix and the sliding sign has been shown to be a reliable predictor of bowel endometriosis [101-104]. These protocols can also be used for surgical planning when the lesion length, circumferential extent, distance to the anal verge, and muscular involvement are reported [105-107]. When specialist-performed DE TVUS is used, the accuracy of surgical planning measurements is similar to MRI [108]. A study comparing DE TVUS performed by a trained versus untrained operator showed the modality predicted bowel endometriosis when performed by the trained operator but not by the untrained operator [109]. Variant 4: Adult. Established postoperative endometriosis diagnosis. New or ongoing symptoms of endometriosis. Follow-up imaging. CT Pelvis With IV Contrast There is no relevant literature to support the use of pelvic CT for patients with an endometriosis diagnosis established by surgery with new or ongoing symptoms. CT with IV contrast could help identify and characterize other etiologies of pelvic pain.