OC77: Sonographic evaluation of posterior deep pelvic endometriosis: role of three‐dimensional ultrasound to assess the extension of the disease

Magnetic Resonance Imaging (MRI) has emerged to be the best diagnostic imaging to evaluate the extent posterior pelvic deep infiltrating endometriosis (DIE). Two dimensional transvaginal sonography (2D TVS) shows some diagnostic limits in the evaluation of the extension of DIE. Three dimensional (3D) ultrasound by using sectional image analysis such as tomographic ultrasound imaging (TUI) could be very similar to MRI. The aim of this study was to evaluate the accuracy of 3D TVS and TUI in the assessment of posterior DIE extension. Sixteen patients with DIE underwent sonographic evaluation prior to laparoscopic surgery, using a GE Voluson 730 Expert ultrasound system. All the patients underwent transvaginal 2D and 3D TVS for DIE. An accurate mapping of the extension of the disease was performed at 2D and 3D sonographic examination and during the laparoscopic procedure. A detailed list of locations, which described the endometriotic/fibrotic infiltrating tissue in terms of presence or absence on different sites of the posterior pelvis was done. A comparison between 2D and 3D sonographic and laparoscopic findings was performed. The TUI mode analyzing volumes in different parallel planes with the possibility to adjust distance between planes and number of slices, seems to be very useful in the evaluation of rectal or sigmoid wall infiltration. In fact the concordance rate in the diagnosis of endometriotic nodes of the pouch of Douglas and uterosacral ligaments was similar for 2D and 3D sonography (94% vs 96%). Whereas the accuracy in the diagnosis of nodes infiltrating the rectal or sigmoid wall, is higher with 3D TUI (85% vs 94%). 3D TVS and TUI may provide accurate informations about the extension of posterior DIE. In particular it improves the diagnosis of the infiltration of the rectal and sigmoid wall and could be useful in the management of these patients.