Accuracy of transvaginal sonography and contrast-enhanced magnetic resonance-colonography for the presurgical staging of deep infiltrating endometriosis.

OBJECTIVE: To investigate the accuracy of transvaginal sonography (TVS) and contrast-enhanced magnetic resonance-colonography (CE-MR-C) for the presurgical assessment of deep infiltrating endometriosis (DIE). METHODS: Ninety women were enrolled prospectively for suspicion of DIE. All patients underwent TVS and CE-MR-C, with each operator blinded to the results of the other exam, before laparoscopy. The sites of DIE examined by both imaging techniques were: rectovaginal septum, pouch of Douglas, uterosacral ligaments, vesicouterine pouch, bowel, bladder and vagina. The presence of adhesions and the involvement of adnexa and of a previous abdominal scar, when there was clinical suspicion, were also evaluated. TVS and CE-MR-C findings were compared with laparoscopic and histological results. RESULTS: Endometriosis was confirmed by laparoscopy in 95.6% (86/90) of cases. In 82.2% (74/90) of patients there was DIE. The global accuracy for TVS in the detection of DIE was 89.2%, sensitivity was 81.1%, specificity was 94.2%, positive predictive value was 89.6%, negative predictive value was 89.0%, the positive likelihood ratio was 13.9 and the negative likelihood ratio was 0.2. For CE-MR-C, these values were 87.2%, 71.1%, 97.1%, 93.7%, 84.6%, 24.4 and 0.3, respectively. CE-MR-C allowed diagnosis of all cases of bowel involvement; the accuracy for infiltration and stenosis was 100%. The accuracy of TVS for rectosigmoid nodules was 91.1% and that for infiltration was 88.9%. CONCLUSIONS: Both TVS and CE-MR-C showed satisfactory results for the presurgical assessment of DIE. TVS appears to be a powerful, simple, feasible, cost-effective tool for preoperative staging of DIE. CE-MR-C is an 'X-ray free' technique, which could be reserved for cases with deep infiltrating rectosigmoid lesions and for the prediction of stenosis and involvement of the upper part of the colon and small intestine.