Comparison of transvaginal sonography and double-contrast barium enema for diagnosing deep infiltrating endometriosis of the posterior compartment.

OBJECTIVES: To compare the diagnostic accuracy of transvaginal sonography (TVS) and double-contrast barium enema (DCBE) in the preoperative detection of deep infiltrating endometriosis (DIE) of the posterior compartment. METHODS: This was a prospective study of 69 consecutive patients with results of pelvic examination or symptoms suggestive of DIE of the posterior compartment. TVS and DCBE were performed before surgery by two groups of physicians specialized in endometriosis, each blinded to the results of the other technique. Imaging data were compared with histopathologic analysis of the resected specimen (gold standard). Sensitivity, specificity, positive and negative predictive values and test accuracies were calculated for both imaging modalities. RESULTS: Sixty seven of the 69 women had a nodule of DIE confirmed at laparoscopy and histopathologic examination. TVS diagnosed DIE in 57 (85%) of these patients, while DCBE revealed the presence of the lesion in 24 (36%) women. For the diagnosis of posterior DIE, TVS and DCBE had, respectively, a sensitivity of 85% and 36%, specificity of 100% and 100%, positive predictive value of 100% and 100%, negative predictive value of 17% and 4% and accuracy of 85.5% and 38%. In patients with pure bowel DIE the sensitivity was 91% and 43%, specificity was 100% and 100%, positive predictive value was 100% and 100%, negative predictive value was 29% and 6% and accuracy was 91% and 45%, respectively. CONCLUSIONS: TVS has a much higher sensitivity than does DCBE in detecting the presence of posterior DIE and should thus be regarded as the imaging modality of choice when there is clinical suspicion of the disease.