OP16.02: MRI and ultrasound fusion imaging for diagnosing deep infiltrating endometriosis

MRI and ultrasound complement each other very well for the screening and diagnosis of endometriosis. Real Time Virtual Sonography (RVS) is a new technique which uses magnetic navigation and a computer software to allow for the synchronized display of real-time US images and multiplanar reconstruction '(MPR) images of magnetic resonance imaging (MRI). The purpose of this study was, for the first time, to evaluate the feasibility and the ability of RVS for diagnosing endometriosis. This study was conducted over one month in patients referred to a trained radiologist, for endometriosis screening. All patients referred for pelvis MRI were offered to undergo US examination with fusion imaging (Hitachi Vision Ascendus). All cases underwent 1.5 T (Tesla) MRI (Siemens Erlangen, Germany) with body phased-array coil. MR imaging protocol included at least 2 FSET2-weigthed planes. The DICOM MRI data set was loaded into the fusion system and displayed together with the ultrasonographic image on the same computer monitor. Both sets of images were synchronized and manually registered using one plane and one anatomical point. Feasibility and ability to image the main anatomical sites of endometriosis (Utero Sacral Ligament- USL, vaginal fornix, rectum, ureters, bladder, adnexa) with RVS imaging were studied. Over the study period, 19 patients, median age 35 [27–49] underwent fusion imaging. Data registration, matching and fusion imaging was feasible within less than 10 minutes in all cases. Overall ability for identifying anatomical landmarks was as follows: USL: US 58,8% (20/34), MRI 100% (34/34), RVS 100% (34/34)- Ureters: US 0%, MRI 100% (34/34), RVS 100% (34/34)- Rectum: US 100% (34/34), MRI 52,9% (9/17), RVS 100% (17/17). Fusion imaging is a novel technology that has a potential for diagnosing endometriosis. Because it combines both US and MRI information, it allows better identification of the main anatomical location of deep endometriosis.