VP62.09: Does tridimensional ultrasonography improve the performance of bidimensional ultrasonography in diagnosing bladder endometriosis?

To evaluate if tridimensional ultrasonography (3D-TVS) improves the performance of bidimensional ultrasonography (2D-TVS) in assessing the presence and characteristics of bladder endometriosis (BE). This prospective study included patients with suspicion of BE based on symptoms and clinical exam. An experienced sonographer performed 2D-TVS. Another experienced sonographer, blinded to results of the previous exam, performed 2D-TVS and 3D-TVS. The scans were performed using a Voluson E10 machine. During 3D-TVS, multiple acquisitions were made in the sagittal and coronal planes; 3D rendering and virtual organ computer-aided analysis (VOCAL) were used. The following parameters were evaluated: presence of BE, largest diameter of BE, volume of BE, distance between the endometriotic nodule, and the ureteral meatus. Ultrasonographic findings were compared with surgical and histological results. 74 patients were included in the study. 23 patients had BE at the surgery. The mean ( ± SD) largest diameter of BE was 2.5 ( ± 1.1) cm. 12 nodules were located in the bladder base, 9 were in the dome, and 2 in the extra-abdominal bladder. The McNemar test demonstrated that the two techniques have similar performance in diagnosing the presence of BE (p = 0.125). The performance of 2D-TVS was: accuracy 87.3%, sensitivity 82.6%, specificity 89.6%, positive predictive value (PPV) 79.2%, negative predictive value (NPV) 91.5%, positive likelihood ratio (LR+) 7.93, and negative likelihood ratio (LR-) 0.19. The performance of 3D-TVS was: accuracy 81.7%, sensitivity 69.2%, specificity 88.9%, PPV 78.3%, NPV 83.3%, LR+ 6.23, and LR- 0.35. The two techniques were similarly precise in estimating the largest diameter of BE (p = 0.652) and the distance between the endometriotic nodule and the ureteral meatus (p = 0.847). 3D-TVS was more precise than 2D-TVS in estimating the volume of BE. 3D-TVS does not improve the performance of 2D-TVS in diagnosing the presence and characteristics of BE (except the volume of BE).