Transvaginal ultrasound (TVS) versus Magnetic Resonance (MR) for diagnosing deep infiltrating endometriosis: a systematic review and meta-analysis

Objective: To perform a systematic review of studies comparing the accuracy of transvaginal ultrasound (TVS) and magnetic resonance imaging (MRI) in diagnosing deep infiltrating endometriosis (DIE) including only studies in which patients underwent both techniques. Methods: An extensive search was carried out in PubMed/MEDLINE and Web of Science for papers from January 1989 to October 2016 comparing TVS and MRI in DIE. Studies were considered eligible for inclusion if they reported on the use of TVS and MRI in the same set of patients for the preoperative detection of endometriosis in pelvic locations in women with clinical suspicion of DIE and using surgical data as a reference standard. Quality was assessed using the QUADAS-2 tool. A random-effects model was used to determine pooled sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR–) and diagnostic odds ratio (DOR). Results: Of 375 citations identified, six studies (n = 424) were considered eligible. For MRI in the detection of DIE in the rectosigmoid, pooled sensitivity was 0.85 (95% CI, 0.78–0.90), specificity was 0.95 (95% CI, 0.83–0.99), LR+ was 18.4 (95% CI, 4.7–72.4), LR– was 0.16 (95% CI, 0.11–0.24) and DOR was 116 (95% CI, 23–585). For TVS in the detection of DIE in the rectosigmoid, pooled sensitivity was 0.85 (95% CI, 0.68–0.94), specificity was 0.96 (95% CI, 0.85–0.99), LR+ was 20.4 (95% CI, 4.7–88.5), LR– was 0.16 (95% CI, 0.07–0.38) and DOR was 127 (95% CI, 14–1126). For MRI in the detection of DIE in the rectovaginal septum, pooled sensitivity was 0.66 (95% CI, 0.51–0.79), specificity was 0.97 (95% CI, 0.89–0.99), LR+ was 22.5 (95% CI, 6.7–76.2), LR– was 0.38 (95% CI, 0.23–0.52) and DOR was 65 (95% CI, 21–204). For TVS in the detection of DIE in the rectovaginal septum, pooled sensitivity was 0.59 (95% CI, 0.26–0.86), specificity was 0.97 (95% CI, 0.94–0.99), LR+ was 23.5 (95% CI, 9.1–60.5), LR– was 0.42 (95% CI, 0.18–0.97) and DOR was 56 (95% CI, 11–275). For MRI in the detection of DIE in the uterosacral ligaments, pooled sensitivity was 0.70 (95% CI, 0.55–0.82), specificity was 0.93 (95% CI, 0.87–0.97), LR+ was 10.4 (95% CI, 5.1–21.2), LR– was 0.32 (95% CI, 0.20–0.51) and DOR was 32 (95% CI, 12–85). For TVS in the detection of DIE in the uterosacral ligaments, pooled sensitivity was 0.67 (95% CI, 0.55–0.77), specificity was 0.86 (95% CI, 0.73–0.93), LR+ was 4.8 (95% CI, 2.6–9.0), LR– was 0.38 (95% CI, 0.29–0.50) and DOR was 12 (95% CI, 7–24). Confidence intervals of pooled sensitivities, specificities and DOR were wide for both techniques in all the locations considered. Heterogeneity was moderate or high for sensitivity and specificity for both TVS and MRI in most locations assessed. According to QUADAS-2, the quality of the included studies was considered good for most domains. Conclusion: The diagnostic performance of TVS and MRI is similar for detecting DIE involving rectosigmoid, uterosacral ligaments and rectovaginal septum.