Dynamic MR imaging of pelvic organ prolapse: spectrum of abnormalities

Complete pelvic floor repair in treating fecal incontinence

Fecal incontinence is associated with 20 to 40% of the patients with pelvic floor prolapse. Successful management of fecal incontinence requires not only an understanding of anorectal function but also a thorough understanding of pelvic floor anatomy and how pelvic floor prolapse affects fecal continence. Imaging techniques have been instrumental in visualizing pelvic floor prolapse and have helped correlate surgical findings. Stabilization of the perineal body appears to be a key component to the success of pelvic floor repair and fecal continence, but the optimal repair is far from being established.

Entérocèle : facteurs de risque clinique et associations à d'autres troubles de la statique pelvienne (à partir de 544 défécographies)

OBJECTIVE

To study, by means of defecography, clinical risk factors of enterocele and association with others pelvic floor disorders.

PATIENTS AND METHODS

Five hundred and forty-four consecutive female patients were investigated by colpocystodefecography with contrast medium in the small bowel. One hundred and thirty-six women with enterocele were compared to 408 women without enterocele.

RESULTS

There were no significant differences in age, obstetrical history (parity, foetal macrosomia, instrumental extractions or perineal tear to delivery) between the two groups. More women with enteroceles had histories of hysterectomies (60% versus 24%) or cystopexies (29% versus 13%). Others pelvic floor disorders were associated in 91% of enterocele: rectocele (25%), cystocele (42%), uterine prolapse (28%), rectal intussusception (52%), rectal prolapse (4%) and abnormal perineal descent (30%). Stress urinary incontinence was significantly more frequent in women without enterocele.

DISCUSSION AND CONCLUSIONS

The study has demonstrated that previous hysterectomy and cystopexy increased the risk of enterocele formation and that enterocele and others pelvic floor disorders are often concomitant. Enterocele may have a pessary effect on urinary disorders. Results of colpocystodefecography reinforce the notion of pelvic floor local disease.

Dynamic assessment of pelvic floor and bony pelvis morphologic condition with the use of magnetic resonance imaging in a multiethnic, nulliparous, and healthy female population

OBJECTIVE

The purpose of this study was to determine dynamic pelvic floor and bony pelvis morphologic condition in asymptomatic multiethnic women.

STUDY DESIGN

Pelvic floor anthropometry, at rest and after the Valsalva maneuver, and pelvimetry were compared with the use of magnetic resonance imaging in nulliparous young volunteers from 5 ethnic groups (n=11 x 5 volunteers: Emirati, other Arab, Filipino, Indian/Pakistani, and European/white volunteers), with the white volunteers as the reference group.

RESULTS

The white volunteers were significantly taller (P <.0001) than the other women. Their levator hiatus was significantly longer than the Emirati women (P=.03) and wider than the Filipino women (P=.04). The bladder neck descent on straining was also significantly greater than the other groups (P <.00001). The white women also had the longest transverse diameter of the pelvic inlet (P=.002). Their sagittal outlet diameter was significantly longer than the Emirati and Arab women (P=.02), and their interspinous diameter was significantly longer than the Arab women (P=.002).

CONCLUSION

Nulliparous, healthy white women have larger levator hiatus and bony pelvis with greater bladder neck descent on straining than non-white women.

Influence of spontaneous and instrumental vaginal delivery on objective measures of pelvic organ support: assessment with the pelvic organ prolapse quantification (POPQ) technique and functional cine magnetic resonance imaging

OBJECTIVE

To determine the influence of spontaneous and instrumented vaginal delivery on objective measures of pelvic organ support.

STUDY DESIGN

Prospective study at a university hospital with two study groups: vaginal spontaneous delivery (n = 26) and vacuum extraction (n = 49). Control group consisted of healthy nulliparous volunteers (n = 20). Participants underwent pelvic organ support evaluation by use of the pelvic organ prolapse quantification (POPQ) examination and postpartum functional cine magnetic resonance imaging (MRI).

RESULTS

Significant differences for individual POPQ component measurements were noted for points Aa and Ba, TVL, and GH (spontaneous delivery versus control) and in addition for Ap, Bp, and D (vacuum extraction versus control). Significant differences for MRI measurements were observed for the position of bladder base, bladder neck, posterior fornix of the vagina, anorectal junction, hiatus perimeter and depth of rectocele.

CONCLUSIONS

Considerable changes in pelvic organ support after vaginal delivery can be demonstrated by a reproducible and reliable clinical classification system (POPQ) and by functional cine magnetic resonance imaging.

Computed Tomography Evaluation of Pelvic Organ Prolapse

OBJECTIVES

Pelvic organ prolapse is a common debilitating condition affecting women. Cross-sectional imaging with magnetic resonance imaging (MRI) depicts pelvic floor anatomy as well as organ prolapse and can complement or replace fluoroscopy. Occasionally, patients cannot tolerate MRI, but multiplanar visualization of pelvic floor soft tissue anatomy and organ prolapse is clinically desired. The objective of this study was to determine if computed tomography (CT) is a potential diagnostic technique in these specific situations for demonstrating organ prolapse and the pelvic floor.

METHODS

Seven women (mean age: 63.5 years) with clinical pelvic organ prolapse were referred for CT of the pelvis from the gynecologic and surgical clinics from November 1998 to September 2001. The CT technique included the following: insufflation of rectal air, positive oral contrast, supine position with knees flexed, and imaging at rest and straining with a single-detector scan in 5 cases (slice thickness of 3 mm, table speed of 5 mm/s, 2-mm reconstruction interval) and a multidetector scan in 1 case (detector collimation of 1 mm, slice thickness of 1.25 mm, 1-mm reconstruction interval). Axial and 3-dimensional images were interpreted.

RESULTS

Computed tomography demonstrated prolapse in 5 of 7 patients. At CT, cystocele was present in 2 of 7 patients, vault or cervical prolapse was present in 4 of 7, enterocele was present in 3 of 7, rectocele was present in 2 of 7, and levator abnormalities were present in 4 of 7. Surgery was performed in 3 of the 5 patients with positive CT findings, and prolapse was confirmed. Surgery was also performed in 1 patient with negative CT findings, and global prolapse was detected.

CONCLUSIONS

Demonstration of pelvic organ prolapse and muscular pelvic floor abnormalities is feasible with CT if the patient strains adequately. In patients who cannot tolerate MRI, CT may be useful as an alternative diagnostic tool.

Functional imaging of the pelvic floor

INTRODUCTION/OBJECTIVE

Pelvic floor dysfunction and associated pelvic organ prolapse represent a major problem in our present-day society, mostly afflicting parous women. Magnetic resonance imaging (MRI) is assuming an increasingly important role in the more accurate delineation of the extent of the problem. This article briefly reviews one of the main radiological methods for the dynamic evaluation of the pelvic floor: functional cine MRI.

METHODS AND MATERIAL

Out of the literature the smallest common denominator for functional cine MRI can be defined as follows: high field system; patient either in supine or sitting position; fast gradient echo sequence; midsagittal slice orientation; either a stack of slices or repeated measurements at the same slice position with the patient at rest or straining; image analysis using the pubococcygeal reference line.

RESULTS

All except two publications stress the usefulness of functional cine MRI in the evaluation of patients with organ descent and prolapse. This well accepted method allows for the visualization of all relevant structures in the anterior, middle and posterior compartment. It is especially useful in the detection of enteroceles, and provides a reliable postoperative follow-up tool. Isolated urinary or stool incontinence are not an indication for functional cine MRI, as is the case in patients with equivocal clinical findings. To date it does not allow for real 3D imaging of the pelvic floor or sufficient determination of fascial defects.

DISCUSSION

Functional cine MRI of the pelvic floor is a promising new imaging method for the detection of organ descent and prolapse in patients with equivocal clinical findings. The combination of function and morphology allows for an innovative view of the pelvic floor, and thus adds to our understanding of the various interactions of the structures.

Bladder imaging using multidetector row computed tomography, volume rendering, and magnetic resonance imaging

Both multidetector row computed tomography (MDCT) and magnetic resonance imaging (MRI) are used to evaluate the bladder noninvasively. MDCT offers fast imaging with near-isotropic data sets optimized for three-dimensional imaging, including the latest software for volume rendering. MRI provides distinctive soft tissue contrast resolution and can perform dynamic imaging without radiation exposure. This article discusses the techniques and protocols of each modality with case illustrations of their application in a range of bladder pathologies to show their respective distinct advantages and limitations.

Dynamic evaluation of female pelvic organ prolapse by extended proctography

More accurate preoperative assessment by DCP or MR imaging hopefully should reduce the incidence of operative failure. These techniques help the surgeon to plan the different components of pelvic reconstructive surgery and, importantly, whether a transvaginal or transabdominal approach will be required. The current trend is toward the transabdominal route. Available evidence suggests that the reoperative rate is halved when the abdominal approach is employed. Large enteroceles and marked vaginal vault prolapse, in particular, are much more amenable to correction by transabdominal surgery. It should be recognized that enteroceles and sigmoidoceles often escape preoperative detection unless radiologic evaluation is performed. Global assessment of pelvic organ prolapse is optimized by ensuring that competing organs are effectively emptied by virtue of a triphasic approach. As expressed succinctly by Halligan, "the global pelvic floor specialist has arrived, and his closest ally is the radiologist".

MR imaging of the bladder

MR imaging of the bladder can now be routinely and easily performed with consistent quality. The latest techniques provide high-resolution images of the soft tissue contrast and the ability to perform dynamic contrast imaging and functional pelvic floor studies. MR imaging fits in as a complimentary tool to cystoscopy and to conventional pelvic floor dynamic studies and can provide a unique imaging perspective of the bladder. It is important, however, to remain cognizant of the limitations of its use in tumor detection and discrimination.

Experience of 4 years with open MR defecography: pictorial review of anorectal anatomy and disease

Functional disorders of the pelvic floor are a common clinical problem. Diagnosis and treatment of these disorders, which frequently manifest with nonspecific symptoms such as constipation or incontinence, remain difficult. Fluoroscopic x-ray defecography has been shown to aid in detection of functional and morphologic abnormalities of the anorectal region. With the advent of open-configuration magnetic resonance (MR) imaging systems, MR defecography with the patient in a vertical position became possible. MR defecography permits analysis of the anorectal angle, the opening of the anal canal, the function of the puborectal muscle, and the descent of the pelvic floor during defecation. Good demonstration of the rectal wall permits visualization of intussusceptions and rectoceles. Excellent demonstration of the perirectal soft tissues allows assessment of spastic pelvic floor syndrome and descending perineum syndrome and visualization of enteroceles. MR defecography with an open-configuration magnet allows accurate assessment of anorectal morphology and function in relation to surrounding structures without exposing the patient to harmful ionizing radiation.

Identificação das estruturas músculo-ligamentares do assoalho pélvico feminino na ressonância magnética

OBJETIVO: Determinar a freqüência de identificação das estruturas músculo-ligamentares do assoalho pélvico por meio de exames de ressonância magnética e avaliar o índice de concordância entre os observadores. MÉTODO: Estudo prospectivo em 20 voluntárias assintomáticas, idade de 20 a 80 anos (média de 50 anos). Realizados exames de ressonância magnética pélvica (1,5 T) nas seqüências turbo spin-eco ponderadas em T1 e T2 nos planos axial e sagital. Os exames foram avaliados por dois observadores independentes, que procuraram identificar os músculos levantador do ânus (músculos coccígeo, pubococcígeo, iliococcígeo e puborretal), obturador interno e compressor da uretra e os ligamentos pubovesical e pubouretral. Os resultados foram comparados com base na freqüência de identificação das estruturas anatômicas e na concordância entre os observadores (índice kappa -- kapa). RESULTADOS: A freqüência de identificação das estruturas variou de 50% a 100%, sendo pouco inferior para os ligamentos. A concordância interobservador na identificação das estruturas foi a seguinte: músculos levantador do ânus e obturador interno (kapa=1), pubococcígeo (kapa=0,62), iliococcígeo (kapa=0,86), puborretal (kapa=0,27), coccígeo (kapa=0) e compressor da uretra (kapa=1), e ligamentos pubovesical (kapa=0,50) e pubouretral (kapa=0,58). CONCLUSÃO: A ressonância magnética de pelve permite identificar as principais estruturas músculo-ligamentares do assoalho pélvico na grande maioria dos indivíduos, com boa concordância interobservador.