Diagnostic imaging of pelvic floor dysfunction

Comparison of magnetic resonance defecography grading with POP-Q staging and Baden-Walker grading in the evaluation of female pelvic organ prolapse

PURPOSE

The physical examination and pelvic imaging with MRI are often used in the pre-operative evaluation of pelvic organ prolapse. The objective of this study was to compare grading of prolapse on defecography phase of dynamic magnetic resonance imaging (dMRI) with physical examination (PE) grading using both the Pelvic Organ Prolapse Quantification (POP-Q) staging and Baden-Walker (BW) grading systems in the evaluation of pelvic organ prolapse (POP).

METHODS

We retrospectively reviewed the charts of 170 patients who underwent dMRI at our institution. BW grading and POP-Q staging were collected for anterior, apical, and posterior compartments, along with absolute dMRI values and overall grading of dMRI. For the overall grading/staging from dMRI, BW, and POP-Q, Spearman rho (ρ) was used to assess the correlation. The correlations between dMRI grading and POP-Q staging were compared to the correlations between dMRI grading and BW grading using Fisher's Z transformation.

RESULTS

A total of 54 patients were included. dMRI grading was not significantly correlated with BW grading for anterior, apical, and posterior compartment prolapse (p > 0.15). However, overall dMRI grading demonstrated a significant (p = 0.025) and positive correlation (ρ = 0.305) with the POP-Q staging system. dMRI grading for anterior compartment prolapse also demonstrated a positive correlation (p = 0.001, ρ = 0.436) with the POP-Q staging derived from measurement locations Aa and Ba. The overall dMRI grade is better correlated with POP-Q stage than with BW grade (p = 0.024).

CONCLUSION

Overall and anterior compartment grading from dMRI demonstrated a significant and positive correlation with the overall POP-Q staging and anterior compartment POP-Q staging, respectively. The overall dMRI grade is better correlated with POP-Q staging than with BW grading.

MAGNETIC RESONANCE IMAGING OF PELVIC FLOOR DYSFUNCTION, REVIEW

Pelvic floor dysfunction is an important medical and social problem in the female population. The impact of pelvic floor disorders (PFD) is likely to grow as the prevalence of these disorders increases with an aging population. Pregnancy and delivery are considered major risk factors in the development of POP and stress urinary incontinence. Pelvic floor dysfunction may involve pelvic organ prolapse and/or pelvic floor relaxation. Organ prolapse can include any combination of the following: urethra (urethrocele), bladder (cystocele), or both (cystourethrocele), vaginal vault and cervix (vaginal vault prolapse), uterus (uterineprolapse), rectum (rectocele), sigmoid colon (sigmoidocele),and small bowel (enterocele).Given the paucity of understanding of PFD pathophysiology ,multicompartmental pathology, the high rate of recurrence and repeat surgery imaging plays a major role in its clinical management.The magnetic resonance imaging (MRI) allows noninvasive, radiation-free, rapid, high-resolution evaluation the multicompartment defects in one examination.Findings reported at MR imaging of the pelvic floor are valuable for selecting candidates for surgical treatment and for indicating the most appropriate surgical approach.

Dynamic Pelvic Magnetic Resonance Imaging Evaluation of Pelvic Organ Prolapse Compared to Physical Examination Findings

OBJECTIVE

To compare dynamic magnetic resonance imaging (dMRI) defecography phase findings with physical examination (PE) grading in the evaluation of pelvic organ prolapse (POP).

METHODS

We retrospectively reviewed 274 consecutive patients who underwent dMRI with defecography. Baden-Walker grading of POP, absolute dMRI values, and grading by dMRI were collected for anterior, apical, and posterior compartments. Anatomically significant POP on PE was defined as Baden-Walker Grade ≥3 and on dMRI by dMRI Grade ≥2. A Spearman's Rank correlation was performed between absolute dMRI values and respective POP grades.

RESULTS

A total of 178 female patients were included. Anatomically insignificant and significant cystoceles had a 26.4% (19/72) and 84.6% (66/78) agreement respectively. Anatomically insignificant and significant apical prolapse had a 2.0% (2/100) and 62.9% (17/27) agreement respectively. Anatomically insignificant and significant posterior prolapse had a 49.5% (51/103) and 78.7% (59/75) agreement respectively. PE detected only 30% (9/30) of total dMRI detected enteroceles and misdiagnosed 10% (3/30) of these patients with a rectocele.

CONCLUSION

The dMRI defecography phase correlated well for anatomically significant prolapse in anterior and posterior compartments. dMRI was superior to PE for enterocele detection and was better able to distinguish an enterocele from a rectocele. Thus, dMRI may have the greatest diagnostic value in cases where the presence of an enterocele is unclear in apical and/or posterior compartments.

Practical guide to dynamic pelvic floor MRI

Pelvic floor dysfunction encompasses a spectrum of functional disorders that result from impairment of the ligaments, fasciae, and muscles supporting the pelvic organs. It is a prevalent disorder that carries a lifetime risk over 10% for undergoing a surgical repair. Pelvic floor weakness presents as a wide range of symptoms, including pain, pelvic pressure or bulging, urinary and fecal incontinence, constipation, and sexual dysfunction. A correct diagnosis by clinical examination alone can be challenging, particularly in cases involving multiple compartments. Magnetic resonance imaging (MRI) allows noninvasive, radiation-free, high soft-tissue resolution evaluation of all three pelvic compartments, and has proved a reliable technique for accurate diagnosis of pelvic floor dysfunction. MR defecography with steady-state sequences allows detailed anatomic and functional evaluation of the pelvic floor. This article provides an overview of normal anatomy and function of the pelvic floor and discusses a practical approach to the evaluation of imaging findings of pelvic floor relaxation, pelvic organ prolapse, fecal incontinence, and obstructed defecation.

LEVEL OF EVIDENCE

5 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1155-1170.

Role of static and dynamic MR imaging in surgical pelvic floor dysfunction

Pelvic floor dysfunction (PFD) is a hidden women's health epidemic in the United States, with over 10% of women having a lifetime risk for undergoing a surgical repair for this problem. Given the paucity of understanding of PFD pathophysiology and the high rate of recurrence and repeat surgery, imaging plays a major role in its clinical management, especially for the preoperative assessment of patients with multicompartment defects and failed surgical repairs. The recent development of fast magnetic resonance (MR) imaging sequences allows noninvasive, radiation-free, rapid, high-resolution evaluation of the entire pelvis in one examination. The H line, M line, organ prolapse (HMO) classification system, which is applied to dynamic MR images, allows consistent standardization and grading of various forms of PFD. In addition, the HMO system clearly defines and differentiates between the two main components of PFD: pelvic floor relaxation and pelvic organ prolapse. In addition to serving as an objective diagnostic tool in patients with surgical PFD, MR imaging has tremendous potential to be used as a research tool in trying to understand the pathophysiology of these complex disorders.

Triphasic MRI of pelvic organ descent: sources of measurement error

PURPOSE

To identify sources of error when measuring pelvic organ displacement during straining using triphasic dynamic magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Ten healthy nulliparous woman underwent triphasic dynamic 1.5 T pelvic MRI twice with 1 week between studies. The bladder was filled with 200 ml of a saline solution, the vagina and rectum were opacified with ultrasound gel. T2 weighted images in the sagittal plane were analysed twice by each of the two observers in a blinded fashion. Horizontal and vertical displacement of the bladder neck, bladder base, introitus vaginae, posterior fornix, cul-de sac, pouch of Douglas, anterior rectal wall, anorectal junction and change of the vaginal axis were measured eight times in each volunteer (two images, each read twice by two observers). Variance components were calculated for subject, observer, week, interactions of these three factors, and pure error. An overall standard error of measurement was calculated for a single observation by one observer on a film from one woman at one visit.

RESULTS

For the majority of anatomical reference points, the range of displacements measured was wide and the overall measurement error was large. Intra-observer error and week-to-week variation within a subject were important sources of measurement error.

CONCLUSION

Important sources of measurement error when using triphasic dynamic MRI to measure pelvic organ displacement during straining were identified. Recommendations to minimize those errors are made.

Clinical examination and dynamic magnetic resonance imaging in vaginal vault prolapse

OBJECTIVE

To estimate the role of dynamic magnetic resonance imaging (MRI) as a diagnostic tool in the evaluation of vaginal apex prolapse in women with previous hysterectomy.

METHODS

Clinical examinations were performed on 51 women presenting with symptoms of prolapse. A preoperative dynamic MRI assessment was performed. The mid pubic line was the reference level used for prolapse grading. The parameters of analysis included 1). correlation by compartments of clinical and MRI grading of prolapse, 2). assessment of the accuracy of clinical examination of the middle compartment, and 3). identification of any additional information provided by MRI. All MRI films were analyzed and validated by the same two observers.

RESULTS

Analysis of each compartment separately revealed poor correlation between clinical and MRI assessment. Of the 51 cases with clinical vault prolapse, 27 (52.9%) cases were clinically overdiagnosed, 3 (6%) were underdiagnosed, and there was agreement in 21 (41.1%) when compared with MRI findings. Postoperative follow-up of the 18 (85%) patients who underwent colposacropexy after intraoperative assessment revealed the presence of cystocele in 4 (26.6%) occasions and rectocele in 3 (20%), which had been detected on MRI but not confirmed intraoperatively.

CONCLUSION

There is poor correlation between clinical and MRI findings when assessing vaginal apex prolapse. Magnetic resonance imaging allows the identification of other prolapsing compartments and may be a complementary diagnostic tool for the diagnosis of complex vaginal apex prolapse.

Surgical management of the apical vaginal defect

PURPOSE OF REVIEW

To review the etiology, presentation, imaging techniques and current surgical management of the apical vaginal defect.

RECENT FINDINGS

Urologists are increasingly managing urinary incontinence and prolapse of the anterior and posterior compartment but most refer the management of the apical defect to gynecologists. A variety of abdominal and vaginal repairs are commonly utilized to repair the apical defect, often based on the surgeon's preference. Of the abdominal repairs, abdominal sacral colpopexy with mesh remains the gold standard. Laparoscopic techniques, although feasible, have not gained widespread acceptance. Of the vaginal restorative procedures there are proponents for uterosacral ligament vault suspension, iliococcygeus and sacrospinous ligament fixation. The uterosacral ligament vault suspension is the most anatomic of the repairs and hence least likely to create a predisposition to future anterior or posterior vaginal wall defects or compromise vaginal function. In rare instances where restorative procedures are discouraged and sexual function is no longer desired, obliterative procedures, which are better tolerated, may be more appropriate.

SUMMARY

The best approach for restoration of vaginal apical support remains controversial with abdominal and vaginal routes commonly utilized. A single approach or procedure based on the surgeon's preference is not always optimal. Procedure selection should be individualized based on the patient's age, comorbidities, prior surgical history and level of physical and sexual activity. The transvaginal uterosacral ligament vaginal vault suspension is increasingly our procedure of choice for management of the apical defect due to its versatility, reduced postoperative morbidity and excellent short-term results.