Original Research Translabial Three-Dimensional Ultrasonography Compared With Magnetic Resonance Imaging in Detecting Levator Ani Defects Kim J. B. Notten, MD, Kirsten B. Kluivers, MD, PhD, Jurgen J. Fütterer, MD, PhD, Karlijn J. Schweitzer, MD, PhD, Jaap Stoker, MD, PhD, Femke E. Mulder, MD, Regina G. Beets-Tan, MD, PhD, Roy F. A. Vliegen, MD, PhD, Patrick M. Bossuyt, MD, PhD, Roy F. P. M. Kruitwagen, MD, PhD, Jan-Paul W. R. Roovers, MD, PhD, and Mirjam Weemhoff, MD, PhD OBJECTIVE: To assess the diagnostic performance of translabial three-dimensional ultrasonography in detecting major levator ani defects in women with pelvic organ prolapse compared with magnetic resonance imaging (MRI) and to assess the interobserver agree- ment in detecting levator ani defects with translabial three-dimensional ultrasonography. METHODS: In a multicenter cohort study, 140 women indicated for primary surgery of pelvic organ prolapse quantification stage II or more cystocele were included. Patients undergoing mesh surgery or concomitant stress incontinence surgery were excluded. All consenting patients underwent translabial three-dimensional ultra- sonography and MRI of the pelvic floor before surgery. Two observers (out of a pool of four observers) assessed translabial three-dimensional ultrasound images; two other observers (out a pool of five observers) assessed MRIs for levator ani muscle damage. In case of disagree- ment, the images were discussed in a consensus meeting. RESULTS: Of the 135 scans, 45 major levator ani defects were detected on ultrasonogram (33.3%) and 32 were confirmed at MRI (23.7%). Of the 41 major levator ani defects detected on MRI, nine were missed at translabial three-dimensional ultrasonogram. Sensitivity was 0.78 (32 of 41) (95% confidence interval [CI] 0.65–0.91) and specificity was 0.86 (81 of 94) (95% CI 0.79–0.93) in detecting major levator ani defects with translabial three-dimensional ultrasonography compared with MRI. There was good agreement scoring levator ani defects on translabial three-dimensional ultrasonography, with a k of 0.67 (95% CI 0.58–0.76); agreement in recognizing major levator ani defects was moderate, with a k of 0.53 (95% CI 0.37–0.69). CONCLUSION: Translabial three-dimensional ultraso- nography shows reasonable agreement with MRI in detecting major levator defects. Because of the moderate interobserver agreement, it will be difficult to implement ultrasonography in daily practice. CLINICAL TRIAL REGISTRATION: Netherlands Trial Regis- ter, www.trialregister.nl, NTR2220. (Obstet Gynecol 2014;124:1190–7) DOI: 10.1097/AOG.0000000000000560 LEVEL OF EVIDENCE: T he levator ani muscle seems to play a key role in pelvic floor dysfunction. Major levator ani defects are associated with pelvic organ prolapse (POP) and POP recurrence. 1–5 Levator ani defects can be detected by palpation, magnetic resonance imaging (MRI), and translabial three-dimensional ultrasound From the Departments of Obstetrics and Gynaecology and Radiology, Maastricht University Medical Center, Maastricht, and University Medical Center Nijmegen, Nijmegen, the Departments of Radiology, Obstetrics and Gynaecology, and Epidemiology, Amsterdam Medical Center, Amsterdam, the Department of Radiology, Atrium Medical Center, Heerlen, and 10GROW–School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands. Funding by ZonMW, project number 171001012. The authors thank the following experts in the field for their contribution to this study: Prof. dr. J. O. DeLancey for providing training sessions and Prof dr H. P. Dietz for assessing ultrasonography scans. Corresponding author: Kim J. B. Notten, MD, Department of Obstetrics and Gynecology, Maastricht University Medical Center, PO Box 5800, 6202 AZ, Maastricht, The Netherlands; e-mail: kim.notten@mumc.nl. Financial Disclosure The authors did not report any potential conflicts of interest. © 2014 by The American College of Obstetricians and Gynecologists. Published by Lippincott Williams & Wilkins. ISSN: 0029-7844/14 1190 VOL. 124, NO. 6, DECEMBER 2014 OBSTETRICS & GYNECOLOGY