Does 4D transperineal ultrasound have additional value over 2D transperineal ultrasound for diagnosing posterior pelvic floor disorders in women with obstructed defecation syndrome?

Objective To establish the diagnostic test accuracy of two‐dimensional (2D) and four‐dimensional (4D) transperineal ultrasound (TPUS) for diagnosis of posterior pelvic floor disorders in women with obstructed defecation syndrome (ODS), in order to assess if 4D ultrasound imaging provides additional value. Methods This was a prospective cohort study of 121 consecutive women with ODS. Symptoms of ODS and pelvic organ prolapse on clinical examination were assessed using validated methods. All women underwent both 2D‐ and 4D‐TPUS. Imaging analysis was performed by two blinded observers. Posterior pelvic floor disorders were dichotomized into presence or absence, according to predefined cut‐off values. In the absence of a reference standard, a composite reference standard was created from a combination of results of evacuation proctography, magnetic resonance imaging and endovaginal ultrasound. Primary outcome measures were diagnostic test characteristics of 2D‐ and 4D‐TPUS for rectocele, enterocele, intussusception and anismus. Secondary outcome measures were interobserver agreement, agreement between the two imaging techniques, and association of severity of ODS symptoms and degree of posterior vaginal wall prolapse with conditions observed on imaging. Results For diagnosis of all four posterior pelvic floor disorders, there was no difference in sensitivity or specificity between 2D‐ and 4D‐TPUS (P = 0.131–1.000). Good agreement between 2D‐ and 4D‐TPUS was found for diagnosis of rectocele (κ = 0.675) and moderate agreement for diagnoses of enterocele, intussusception and anismus (κ = 0.465–0.545). There was no difference in rectocele depth measurements between the techniques (19.9 mm for 2D vs 19.0 mm for 4D, P = 0.802). Interobserver agreement was comparable for both techniques, although 2D‐TPUS had excellent interobserver agreement for diagnosis of enterocele and rectocele depth measurements, while this was only moderate and good, respectively, for 4D‐TPUS. Diagnoses of rectocele and enterocele on both 2D‐ and 4D‐TPUS were significantly associated with degree of posterior vaginal wall prolapse on clinical examination (odds ratio (OR) = 1.89–2.72). The conditions observed using either imaging technique were not associated with severity of ODS symptoms (OR = 0.82–1.13). Conclusions There is no evidence of superiority of 4D ultrasound acquisition to dynamic 2D ultrasound acquisition for the diagnosis of posterior pelvic floor disorders. 2D‐ and 4D‐TPUS could be used interchangeably to screen women with symptoms of ODS

Design and Validation of a 3D Virtual Reality Desktop System for Sonographic Length and Volume Measurements in Early Pregnancy Evaluation

PurposeTo design and validate a desktop virtual reality (VR) system, for presentation and assessment of volumetric data, based on commercially off-the-shelf hardware as an alternative to a fully immersive CAVE-like I-Space VR system. MethodsWe designed a desktop VR system, using a three-dimensional (3D) monitor and a six degrees-of-freedom tracking system. A personal computer uses the V-Scope (Erasmus MC, Rotterdam, The Netherlands) volume-rendering application, developed for the I-Space, to create a hologram of volumetric data. Inter- and intraobserver reliability for crown-rump length and embryonic volume measurements are investigated using Bland-Altman plots and intraclass correlation coefficients. Time required for the measurements was recorded. ResultsComparing the I-Space and the desktop VR system, the mean difference for crown-rump length is -0.34% (limits of agreement -2.58-1.89, 2.24%) and for embryonic volume -0.92% (limits of agreement -6.97-5.13, +/- 6.05%). Intra- and interobserver intraclass correlation coefficients of the desktop VR system were all >0.99. Measurement times were longer on the desktop VR system compared with the I-Space, but the differences were not statistically significant. ConclusionsA user-friendly desktop VR system can be put together using commercially off-the-shelf hardware at an acceptable price. This system provides a valid and reliable method for embryonic length and volume measurements and can be used in clinical practice. (c) 2014 Wiley Periodicals, Inc. J Clin Ultrasound43:164-170, 2015

Comparing the diagnostic accuracy of three ultrasound modalities for diagnosing obstetric anal sphincter injuries.

BACKGROUND: The optimal imaging modality of obstetric anal sphincter injuries (OASIs) needs to take into consideration convenience, availability and ability to assess the sphincter morphology. Endoanal ultrasound is currently regarded as the reference standard but is not widely available in obstetric units. Exoanal alternatives exist, such as three-dimensional (3D) introital or transperineal ultrasound, which are already readily available in most obstetrics and gynecology units. OBJECTIVES: The primary objective was to evaluate the diagnostic accuracy of 3D introital and 3D transperineal ultrasound compared to 3D endoanal ultrasound as the reference standard for the detection of anal sphincter defects in women who sustained obstetric anal sphincter injuries. The secondary objective was to correlate diagnosis of anal sphincter defect on imaging to symptoms of anal incontinence, and to assess patient discomfort experienced for each imaging modality STUDY DESIGN: A cross-sectional study of 250 women who sustained OASIs, all underwent 3D introital, transperineal and endoanal ultrasound. Introital and transperineal ultrasound were assessed using tomographic ultrasound imaging. All completed a validated modified St Mark's Score and Visual Analogue Score for discomfort. Optimal cut-off values for a significant defect on tomographic ultrasound imaging were defined as those with the greatest sensitivity and specificity based on Receiver Operating Characteristic curves with endoanal ultrasound as reference standard. Diagnostic test characteristics of introital and transperineal ultrasound using these optimal cut-offs were calculated. RESULTS: Optimal cut-off for a significant external anal sphincter defect was ≥3/7 slices; sensitivity and specificity were 0.65 and 0.75 on introital and 0.70 and 0.69 on transperineal ultrasound respectively. Optimal cut-off for a significant internal anal sphincter defect was ≥2/5 slices; sensitivity and specificity were 0.59 and 0.84 on introital and 0.43 and 0.97 on transperineal ultrasound. The Area Under the Curve for diagnosing external and internal anal sphincter defects ranged from 0.70 - 0.74 (p<0.001) for introital and transperineal. Positive predictive value for external and internal sphincter defects ranged from 0.37-0.63 and negative predictive value ranged from 0.85-0.93 for transperineal and introital ultrasound. Endoanal ultrasound was the only modality for a defect to correlate with symptoms; mean modified St Mark's score 2.4 (SD 4.1) for defect sphincter and 0.9 (SD 2.7) for intact sphincter (p<0.01). Introital and transperineal ultrasound were associated with less discomfort than endoanal ultrasound. CONCLUSION: Endoanal ultrasound remains the most accurate diagnostic imaging modality. With low positive predictive values, introital and transperineal ultrasound are not suitable for identifying sphincter defects; however high negative predictive values show a good ability to detect an intact sphincter. The optimal cut-off number of slices on tomographic ultrasound imaging for external and internal anal sphincters allows for standardisation of a significant defect. In women with a history of OASI, introital and transperineal ultrasound are suitable to screen for an intact sphincter if endoanal ultrasound is not available. Women with defects seen should then have endoanal ultrasound to verify the diagnosis

Diagnostic test accuracy of MRI and pelvic floor ultrasound for diagnosis of levator ani muscle avulsion.

OBJECTIVE: To estimate diagnostic test accuracy of magnetic resonance imaging (MRI) and pelvic floor ultrasound for diagnosing levator ani muscle (LAM) avulsion in a general population, with a view to establish if ultrasound could substitute MRI to diagnose LAM avulsion. METHODS: Cross-sectional study on 135 women four years after their first delivery. Signs and symptoms were assessed using validated methods. All underwent 4D transperineal ultrasound (TPUS), 3D endovaginal ultrasound (EVUS) and MRI. Images were acquired at rest, squeeze and Valsalva and analysed by two blinded observers. Pre-defined cut-off values were used to diagnose LAM avulsion. In the absence of a reference standard, latent class analysis (LCA) was used to establish diagnostic test characteristics for LAM avulsion as the primary outcome measure. Secondary outcomes were kappa agreement between imaging techniques, intra-class correlation (ICC) for hiatal measurements at rest, squeeze and Valsalva, and correlation with signs and symptoms of pelvic floor dysfunction. RESULTS: Prevalence of LAM avulsion with MRI was 22.9%, TPUS 11.1%, and EVUS 17.8%. Prevalence based on LCA was 15.7%. Sensitivity of TPUS (71%; CI 50-90) and EVUS (91%; CI 74-100) for LAM avulsion is lower than MRI (100%; CI 84-100). Specificity of TPUS (100%; CI 97-100) and EVUS (95%; CI 91-99) is higher than MRI (91%; CI 85-97). MRI (PPV 95% and NPV 100%) and EVUS (PPV 100% and NPV 98%) have high predictive values for assessment of major LAM avulsion and correlate to anterior vaginal wall prolapse. TPUS has high predictive values for minor LAM avulsion (PPV 100% and NPV 95%). Agreement for diagnosis of LAM avulsion (κ 0.69) and hiatal measurements (ICC 0.60-0.81) was highest between MRI and EVUS. CONCLUSION: Pelvic floor ultrasound can be implemented as a triage test to assess parous women for LAM avulsion because of its high specificity. Ultrasound cannot substitute MRI because of a lower sensitivity. The predictive ability of ultrasound is moderate for presence and very good for absence of LAM avulsion. A positive test should be re-confirmed by a different observer or imaging technique. This article is protected by copyright. All rights reserved