OC13.04: Magnetic resonance imaging and transvaginal modified ultrasonography in the diagnosis of rectosigmoid endometriosis

The aim of our study was to compare the diagnostic accuracy of transvaginal tenderness guided ultrasonography and pelvic magnetic resonance imaging (MRI) in the identification of rectosigmoid endometriosis. The study was performed in 59 patients suspected to have deep pelvic endometriosis, and underwent both MRI and transvaginal tenderness guided ultrasonography preoperatively. The modified tenderness-guided approach consisted not only of particular attention in the eventual painful sites in the posterior fornix but also in the introduction of more ultrasound transmission gel in the probe cover to better visualize the near-field area. MRI was carried out using turbo spin-echo (TSE) sequences in T1, T2 and weighted fat-suppressed T1. In addition to morphological findings (thickening, irregular and stellar aspects), MRI provides features based on signal intensity (presence of hyperintense foci on T1-weighted). Rectosigmoid endometriosis was present 51% of patients. The sensitivity, specificity, positive and negative predictive values (+/− 95% confidence intervals) of modified transvaginal ultrasonography and different MRI findings, alone or combined, are reported in the table. Signal intensity abnormalities used alone are related to significantly lower sensitivity in comparison with ultrasonography and combined MRI. In the diagnosis of rectosigmoid endometriosis, MRI shows similar accuracy in comparison with modified ultrasonographic approach only if used in a combined manner, morphological and signal intensity evaluation. OC13.04: Table