ANATOMICAL LOCALIZATION OF DEEP INFILTRATING ENDOMETRIOSIS: 3D MRI RECONSTRUCTIONS

1. Abstract Purpose The goal of this study was to determine the accuracy of 3D MRI reconstructions obtained with segmentation technique in the preoperative assessment of deep infiltrating endometriosis (DIE) and in particular to evaluate rectosigmoid and bladder wall involvement. Materials and methods Institutional review board approval for this study was obtained, and each patient gave written informed consent. Fifty-seven consecutive patients with diagnosis of DIE who had undergone pelvic MRI at 1.5 T before surgery between 2007 and 2011, were retrospectively evaluated and 3D post-processed in order to obtain a detailed mapping of DIE. A blinded reader interpreted images. MRI results were compared with surgical findings and were scored by using a four-point scale (0_3 score). Results 36/57 patients with symptomatic DIE underwent surgery: 18/36 had endometriotic nodules infiltrating the recto-uterine pouch, 12/36 the vescico-uterine pouch and 6/36 the rectovaginal pouch. The sensitivity of MRI and 3D-MRI versus surgery was respectively 64% versus 83%; diagnostic accuracy of 3D-MRI respect to MRI alone was 86% versus 67% for localization; 86% versus 67% for dimension; 79% versus 58% for rectosigmoid infiltration; 92% versus 75% for bladder infiltration. Conclusions In this preliminary study 3D MRI reconstructions obtained with semi-automatic method of segmentation provided encouraging results for staging DIE preoperatively. In fact, the addition of 3D MRI reconstructions improved diagnostic accuracy and staging of DIE providing the exact volume of the lesions and enabling a precise mapping of these before surgery. Key words: Endometriosis; MRI; 3D reconstructions; semi-automatic segmentation; wall infiltration; laparoscopyc or robotic surgery