OC11.01: Prevalence of deep endometriosis in patients of a second level ultrasound laboratory and tissue US characterization of nodules using VOCAL

To evaluate 1. the prevalence of ultrasonographic diagnosis of deep endometriosis in patients with clinical suspicion and 2. to assess mean gray value (MGV) of nodules of deep endometriosis in different location also evaluating the reproducibility of method. We included in the study 215 patients with clinical suspicion of endometriosis referred to our ultrasound laboratory of second level in 2009–2010. All patients were submitted to detailed ultrasonography. An operator evaluate 57 volumes from histologically confirmed nodules to calculate the MGV from each nodule using the Virtual Organ Computer-Aided Analysis (VOCAL) software with a semiautomated 2-cm sphere sampling from the central part of the nodule. In the same patients the MGV was also obtained from the myometrium of fundal part of the uterus. To evaluate the reproducibility in a sample of 24 volumes, two different observers calculated the MGV. Each examiner was to review the volumes twice for assessing intraobserver agreement using (ICC). Of the 215 patients included in the first study, 98 showed lesions suspected to be deep endometriosis (prevalence 46%). In 39 patients (40%) more than one lesion was suspected. In the second study in rectosigmoid lesions (n = 34) the mean value of MGV was significantly higher in comparison with the MGV of the rectovaginal septum (n = 23) (P 0.95). The present study shows an high prevalence of ultrasonographic diagnosis of deep endometriosis in a group of women at risk and demonstrates that a detailed ultrasonographic evaluation can identify a possible cause of pelvic pain in most cases. The use of VOCAL software seems to be able to identify different ultrasound tissue characteristics on the basis of locations of nodules of deep endometriosis.