Department of Obstetrics and Gynecology, Division of Obstetrics and Prenatal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands.
Ultrasound Obstet Gynecol. 2012 Jul;40(1):87-92. doi: 10.1002/uog.10129.
Virtual reality is a novel method of visualizing ultrasound data with the perception of depth and offers possibilities for measuring non-planar structures. The levator ani hiatus has both convex and concave aspects. The aim of this study was to compare levator ani hiatus volume measurements obtained with conventional three-dimensional (3D) ultrasound and with a virtual reality measurement technique and to establish their reliability and agreement.
100 symptomatic patients visiting a tertiary pelvic floor clinic with a normal intact levator ani muscle diagnosed on translabial ultrasound were selected. Datasets were analyzed using a rendered volume with a slice thickness of 1.5 cm at the level of minimal hiatal dimensions during contraction. The levator area (in cm(2)) was measured and multiplied by 1.5 to get the levator ani hiatus volume in conventional 3D ultrasound (in cm(3)). Levator ani hiatus volume measurements were then measured semi-automatically in virtual reality (cm(3) ) using a segmentation algorithm. An intra- and interobserver analysis of reliability and agreement was performed in 20 randomly chosen patients.
The mean difference between levator ani hiatus volume measurements performed using conventional 3D ultrasound and virtual reality was 0.10 (95% CI, - 0.15 to 0.35) cm(3). The intraclass correlation coefficient (ICC) comparing conventional 3D ultrasound with virtual reality measurements was > 0.96. Intra- and interobserver ICCs for conventional 3D ultrasound measurements were > 0.94 and for virtual reality measurements were > 0.97, indicating good reliability for both.
Levator ani hiatus volume measurements performed using virtual reality were reliable and the results were similar to those obtained with conventional 3D ultrasonography.
虚拟现实是一种可视化超声数据的新方法，具有深度感知能力，并为测量非平面结构提供了可能性。肛提肌裂孔既有凸面又有凹面。本研究旨在比较常规三维（3D）超声和虚拟现实测量技术获得的肛提肌裂孔容积测量值，并确定其可靠性和一致性。
选择 100 名因经阴道超声诊断为正常完整肛提肌而就诊于三级盆底诊所的有症状患者。在收缩时最小裂孔尺寸水平上，使用层厚为 1.5cm 的渲染体积对数据集进行分析。测量肛提肌面积（cm²），并将其乘以 1.5 以获得常规 3D 超声（cm³）中的肛提肌裂孔容积。然后使用分割算法在虚拟现实中半自动测量肛提肌裂孔容积（cm³）。对 20 名随机选择的患者进行了可靠性和一致性的内部和观察者间分析。
常规 3D 超声和虚拟现实测量的肛提肌裂孔容积测量值之间的平均差异为 0.10cm³（95%置信区间，-0.15 至 0.35）。比较常规 3D 超声与虚拟现实测量值的组内相关系数（ICC）>0.96。常规 3D 超声测量的观察者内和观察者间 ICC 均>0.94，虚拟现实测量的 ICC 均>0.97，表明两者均具有良好的可靠性。
使用虚拟现实进行的肛提肌裂孔容积测量具有可靠性，并且结果与常规 3D 超声检查获得的结果相似。
