OP20.04: Is experience of sonographers sufficient to diagnose deep infiltrating endometriosis and bowel involvement by transvaginal ultrasonography?

Some authors think that transvaginal ultrasonography (TVUS) should be the first-line imaging examination for diagnosing deep infiltrating endometriosis (DIE) and rectal involvement. However, studies on diagnostic accuracy are few and provided by very specialized centers. The aim of the study was to assess and compare the accuracy of TVUS for diagnosing DIE and bowel involvement by trained or untrained sonographers for DIE imaging. An observational study of patients with clinical suspicion of DIE was performed between October 2004 and April 2011. For the diagnosis of DIE, TVUS was performed by trained or/and untrained sonographers. Trained sonographers had a theorical and surgical formation followed by self assessment. Patients were defined positive for DIE by surgical and histological diagnosis. Sensibility (Se), specificity (Sp) and area under ROC curve (AUC) were calculated with a 95% confidence interval (CI) for trained and untrained sonographers, for the diagnosis of DIE and rectal involvement, when there was a significant association (p < 0.05). 115 patients were included: 100 (87%) had DIE, and 34 (29.6%) bowel involvement. Seventy patients had TVUS performed by a trained sonographer and 56 by untrained sonographers. For the diagnosis of DIE, trained sonographer had a significant association (p = 0.02) with a Se of 58% (95% CI, 46–70), a Sp of 87.5% (95% CI, 63–100), an AUC of 0.73 (95% CI, 0.59–0.87). For untrained sonographers, there was no significant association for the diagnosis of DIE (p = 0.58) and the AUC was 0.56 (95% CI (0.52–0.61). For rectal involvement, trained sonographer had a Se of 40% (95% CI, 23–59), a Sp of 93% (95% CI, 86–100) with an AUC of 0.67 (95% CI, 0.56–0.77). None of untrained sonographers diagnosed a bowel involvement while it was present in 26% of their patients (14/54). TVUS is not sufficient to diagnose deep infiltrating endometriosis and predict bowel involvement, particularly when performed by untrained sonographers.