Agreement and reliability of pelvic floor measurements during contraction using three-dimensional pelvic floor ultrasound and virtual reality
Article first published online: 29 JUN 2012
Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Ultrasound in Obstetrics & Gynecology
Volume 40, Issue 1, pages 87–92, July 2012
How to Cite
Speksnijder, L., Rousian, M., Steegers, E. A. P., Van Der Spek, P. J., Koning, A. H. J. and Steensma, A. B. (2012), Agreement and reliability of pelvic floor measurements during contraction using three-dimensional pelvic floor ultrasound and virtual reality. Ultrasound Obstet Gynecol, 40: 87–92. doi: 10.1002/uog.10129
- Issue published online: 29 JUN 2012
- Article first published online: 29 JUN 2012
- Accepted manuscript online: 1 NOV 2011 11:07AM EST
- Manuscript Accepted: 18 OCT 2011
- 3D ultrasound;
- levator hiatus;
- pelvic floor muscles;
- reliability and agreement;
- virtual reality
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 cm2) was measured and multiplied by 1.5 to get the levator ani hiatus volume in conventional 3D ultrasound (in cm3). Levator ani hiatus volume measurements were then measured semi-automatically in virtual reality (cm3) 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) cm3. 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. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.