The evolution of ultrasound in urogynecology

Transperineal and endovaginal ultrasound for evaluating suburethral masses: comparison with magnetic resonance imaging

OBJECTIVE

To evaluate the utility of pelvic floor ultrasound (US) in the detection and evaluation of suburethral masses, using magnetic resonance imaging (MRI) as the reference standard.

METHODS

This was a retrospective analysis of US and MRI scans of all women with a suburethral mass on clinical examination at a single urogynecology clinic over a 13-year period (February 2007 to March 2020). All women were examined using two-dimensional transperineal US (2D-TPUS) with or without three-dimensional endovaginal US (3D-EVUS). All patients underwent unenhanced T1-weighted and T2-weighted MRI, which was considered the reference standard in this study. Presence of a suburethral mass and its size, location, connection with the urethral lumen and characteristics were evaluated on both pelvic floor US and MRI. Agreement between pelvic floor US and MRI was assessed using intraclass correlation coefficients (ICC; 3,1).

RESULTS

Forty women suspected of having a suburethral mass on clinical examination underwent both MRI and US (2D-TPUS with or without 3D-EVUS). MRI detected a suburethral mass in 34 women, which was also detected by US. However, US also identified a suburethral mass in the remaining six women. Thus, the agreement between US and MRI for detecting a suburethral mass was 85% (95% CI, 70.2-94.3%). The ICC analysis showed good agreement between MRI and 2D-TPUS for the measured distance between the suburethral mass and the bladder neck (ICC, 0.89; standard error of measurement (SEM), 3.64 mm) and excellent agreement for measurement of the largest diameter of the mass (ICC, 0.93; SEM, 4.31 mm). Good agreement was observed between MRI and 3D-EVUS for the measured distance from the suburethral mass to the bladder neck (ICC, 0.88; SEM, 3.48 mm) and excellent agreement for the largest diameter of the suburethral mass (ICC, 0.94; SEM, 4.68 mm).

CONCLUSIONS

2D-TPUS and 3D-EVUS are useful in the imaging of suburethral masses. US shows good-to-excellent agreement with MRI in identifying and measuring suburethral masses; therefore, the two modalities can be used interchangeably depending on availability of equipment and expertise. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. - Legal Statement: This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Translabial US and Dynamic MR Imaging of the Pelvic Floor: Normal Anatomy and Dysfunction

Pelvic floor dysfunction (PFD) is a common condition that typically affects women older than 50 years and decreases the quality of life. Weakening of support structures can involve all three pelvic compartments and cause a combination of symptoms, including constipation, urinary and fecal incontinence, obstructed defecation, pelvic pain, perineal bulging, and sexual dysfunction. The causes of PFD are complex and multifactorial; however, vaginal delivery is considered a major predisposing factor. Physical examination alone is limited in the evaluation of PFD; it frequently leads to an underestimation of the involved compartments. Imaging has an important role in the clinical evaluation, yielding invaluable information for patient counseling and surgical planning. Three- and four-dimensional translabial ultrasonography (US) is a relatively new imaging modality with high accuracy in the evaluation of PFD such as urinary incontinence, pelvic organ prolapse, and puborectalis avulsion. Evaluation of mesh implants is another important indication for this modality. Dynamic magnetic resonance (MR) imaging of the pelvic floor is a well-established modality for pelvic floor evaluation, with high-resolution images yielding detailed anatomic information and dynamic sequences yielding functional data. Specific protocols and dedicated image interpretation are required with both of these imaging methods. In this article, the authors review the normal anatomy of the female pelvic floor by using a practical approach, discuss the roles of translabial US and MR imaging in the investigation of PFD, describe the most appropriate imaging protocols, and illustrate the most common imaging findings of PFD in the anterior, middle, and posterior compartments of the pelvis. Online supplemental material is available for this article. ^©RSNA, 2018.

Detection of Subpubic Tumor Causing Bladder Outlet Obstruction by 3D Perineal Ultrasound

This case report shows that 3D perineal ultrasound can be superior to clinical examination and routine 2D perineal ultrasound in the detection of an unusual subpubic tumor. A 73-year-old female patient was referred to our urogynecological outpatient unit complaining of over-active bladder symptoms and voiding dysfunction for 3 years. Gynecological examination found no signs of pelvic organ prolapse or abnormality in the vaginal cavity. Routine 2D perineal ultrasound showed substantial residual urine (ca. 300 ml on catheter) and limited bladder neck mobility, but no signs of pelvic organ prolapse. Use of standardized 3D perineal ultrasound revealed a 24 × 26 × 32 mm spherical, hypoechoic tumor below the pubic symphysis between the distal urethra and the pubic bones. This structure was mistaken for the pubic symphysis in the midline on 2D ultrasound performed earlier. At surgery, the tumor was completely excised through a vaginal incision between the urethra and the pubic symphysis. After an uneventful postoperative recovery the patient developed de-novo stress urinary incontinence, which was corrected successfully by the insertion of a retropubic tension-free suburethral sling after an interval of 8 weeks. After a further follow-up of 8 weeks the patient reported well-being, urinary continence and no voiding dysfunction; no abnormalities were found on examination. In conclusion, 3D perineal ultrasound is a useful additional tool for the diagnostic workup of bladder outlet obstruction.

Reliability of superficial male pelvic floor structural measurements using linear-array transperineal sonography

This study evaluated reliability of measures for superficial structures of the male pelvic floor (PF) obtained via transperineal sonography. Two embalmed cadavers were dissected to identify positioning of muscles on and around the bulb of the penis and to confirm the PF protocol. Cross-sectional area (CSA) and linear thickness of the bulb of the penis, urethra, bulbospongiosus (BS) muscles, and ischiocavernosus (IC) muscles were measured on 38 transverse images from 20 male patients by three raters with varied study knowledge and sonographic experience. Intra- and inter-rater reliability were calculated with two-way, mixed effects intra-class correlation coefficients. Measures of the bulb of the penis had the best reliability. CSA of all muscles and sagittal thickness of the BS near the central tendon had good reliability. Reliability varied for rater-identified thickest muscle region and measures of the urethra. Our study suggests that structures of the male PF can be reliably evaluated using a transperineal sonographic approach.

Use of ultrasound in the clinical evaluation of women following colpocleisis

OBJECTIVE

To assess the role of transperineal ultrasound in the postoperative evaluation of patients undergoing colpocleisis.

METHODS

Patients who underwent colpocleisis between July 2009 and January 2011 completed the pelvic floor distress inventory questionnaire (PFDI-20) and underwent pelvic organ prolapse quantification (POP-Q) examination and four-dimensional (4D) transperineal ultrasound. Volumes were analyzed offline for assessment of pelvic organ descent, levator hiatal dimensions, levator avulsion trauma and the location of the colpocleisis scar.

RESULTS

The study included 16 women, of mean ± SD age 75.7 ± 2.9 years, median body mass index 28 (range, 21-32) kg/m2 and median parity 2 (range, 0-5); one woman was nulliparous. Nine (56.2%) women were posthysterectomy. The median interval from surgery to ultrasound examination was 6.5 (range, 2-19) months. Most patients did not have symptoms of prolapse. The median pelvic organ prolapse distress inventory (POPDI-6) score was 37.5 (range, 0-75) and the median postoperative clinical POP-Q stage was 1 (range, 0-2). Ultrasound demonstrated clear visualization in all patients. Ten had avulsion defects (six were bilateral). Ultrasound estimated greater prolapse descent for all compartments when compared with the clinical examination. However, this difference was significant for anterior and posterior descent, but not for apical descent. In two women urethral diverticulum was detected on ultrasound; it was neither symptomatic nor clinically apparent.

CONCLUSIONS

4D transperineal ultrasound seems to be a potentially effective tool for the evaluation of vaginal anatomic and functional changes following colpocleisis surgery. Future investigation of the association between ultrasound findings and patients' subjective symptoms in a larger cohort is warranted.