Deep pelvic endometriosis: accuracy of pelvic MRI completed by MR colonography.

PURPOSE: This study assessed the diagnostic accuracy of pelvic magnetic resonance (MR) imaging completed by MR colonography for the preoperative evaluation of deep pelvic endometriosis in patients undergoing laparoscopic surgery. MATERIALS AND METHODS: A total of 143 patients (mean age 34.3 ± 5.1 years) with a clinical suspicion of deep pelvic endometriosis were assessed by pelvic MR and MR colonography. All patients underwent laparoscopic surgery 3-10 weeks after the MR examination. The presence, location, number and extent of endometriotic lesions were evaluated. Data obtained with MR were compared with surgical findings. MR sensitivity, specificity, positive (PPV) and negative (NPV) predictive values and diagnostic accuracy values were calculated for each site by considering the laparoscopic and histological findings as the reference standard. RESULTS: Laparoscopy confirmed the presence of endometriosis in 119/143 patients (83%); in 76/119 (64%) deep pelvic endometriosis was diagnosed, whereas in the remaining 43/119 (36%), superficial peritoneal implants and endometriomas were found. In 32/119 (27%) patients, intestinal lesions were detected. MR had sensitivity, specificity, PPV, NPV and diagnostic accuracy values of 67-100%, 85-100%, 83-100%, 84-100% and 84-100%, respectively, in recognising lesions located in different pelvic sites. CONCLUSIONS: MR imaging combined with colonography is a highly accurate tool for characterising deep endometriotic lesions in patients scheduled for laparoscopic surgery. In particular, MR colonography has very high accuracy in detecting colorectal involvement.