Practical guide to dynamic pelvic floor MRI

Quantifying the effects of five rehabilitation training methods on the ability of elderly men to control bowel movements: a finite element analysis study

Purpose

The study aims to develop a finite element model of the pelvic floor and thighs of elderly men to quantitatively assess the impact of different pelvic floor muscle trainings and the urinary and defecation control ability.

Methods

A finite element model of the pelvic floor and thighs of elderly men was constructed based on MRI and CT. Material properties of pelvic floor tissues were assigned through literature review, and the relative changes in waistline, retrovesical angle (RVA) and anorectad angulation (ARA) to quantitatively verify the effectiveness of the model. By changing the material properties of muscles, the study analyzed the muscle strengthening or impairment effects of the five types of rehabilitation training for four types of urination and defecation dysfunction. The changes in four outcome indicators, including the retrovesical angle, anorectad angulation, stress, and strain, were compared.

Results

This study indicates that ARA and RVA approached their normal ranges as material properties changed, indicating an enhancement in the urinary and defecation control ability, particularly through targeted exercises for the levator ani muscle, external anal sphincter, and pelvic floor muscles. This study also emphasizes the effectiveness of personalized rehabilitation programs including biofeedback, exercise training, electrical stimulation, magnetic stimulation, and vibration training and advocates for providing optimized rehabilitation training methods for elderly patients.

Discussion

Based on the results of computational biomechanics, this study provides foundational scientific insights and practical recommendations for rehabilitation training of the elderly's urinary and defecation control ability, thereby improving their quality of life. In addition, this study also provides new perspectives and potential applications of finite element analysis in elderly men, particularly in evaluating and designing targeted rehabilitation training.

Comparison of Dynamic Magnetic Resonance Defecography With Clinical Examination in Diagnosing Pelvic Floor Dysfunction: An Observational Study

BACKGROUND

Pelvic floor dysfunction (PFD) is frequently reported in both sexes. Dynamic magnetic resonance defecography (DMRD) is the preferred modality, mainly due to its superiority and complementary role in clinical examination. However, studies from the perspective of Indian patients are scarce and mostly restricted to females. Thus, we assessed the diagnostic performance of DMRD in patients with PFD and correlated the findings with those on clinical examination.

MATERIALS AND METHODS

This prospective, observational study involved 57 adult patients of either sex, presenting with pelvic floor symptoms (PFS) and diagnosed with PFD. Initially, the patients underwent clinical examination, and diagnosis was recorded. Subsequently, the patients were subjected to DMRD. The findings were correlated with the Pearson "r" correlation coefficient.

RESULTS

A significantly greater proportion of patients had involvement of multiple compartments (36 vs. 12, p<0.001), cystocele (23 vs. 8, p=0.002), and rectal prolapse (25 vs. 14, p=0.030) on DMRD than clinical examination, while there was no significant difference regarding uterine prolapse (p=0.789). Grading of cystocele and rectal prolapse as well as diagnosis of enterocele/peritoneocele, rectocele, and intussusception could be done only with DMRD. DMRD had a strong and significant correlation with clinical examination regarding cystocele (r=0.943, p=0.003), uterine prolapse (r=0.972, p=0.001), and rectal prolapse (r=0.951, p=0.001).

CONCLUSIONS

DMRD demonstrated significantly better performance in the diagnosis of multiple compartment involvement, cystocele, and rectal prolapse. DMRD and clinical examination were significantly correlated regarding the diagnosis of cystocele, uterine prolapse, and rectal prolapse. Thus, DMRD provides information, in addition to the clinical examination, and should be used in symptomatic patients.

[Dynamic magnetic resonance imaging of the pelvic floor: clinical application]

BACKGROUND

Dynamic magnetic resonance imaging (MRI) of the pelvic floor plays a key role in imaging complex pelvic floor dysfunction. The simultaneous detection of multiple findings in a complex anatomic setting renders correct analysis and clinical interpretation challenging.

OBJECTIVES

The most important aspects (anatomy of the pelvic floor, three compartment model, morphological and functional analysis, reporting) for a successful clinical use of dynamic MRI of the pelvic floor are summarized.

MATERIALS AND METHODS

Review of the scientific literature on dynamic pelvic MR imaging with special consideration of the joint recommendations provided by the expert panel of ESUR/ESGAR in 2016.

RESULTS

The pelvic floor is a complex anatomic structure, mainly formed by the levator ani muscle, the urethral support system and the endopelvic fascia. Firstly, morphological changes of these structures are analysed on the static sequences. Secondly, the functional analysis using the three compartment model is performed on the dynamic sequences during squeezing, straining and defecation. Pelvic organ mobility, pelvic organ prolapse, the anorectal angle and pelvic floor relaxation are measured and graded. The diagnosis of cystoceles, enteroceles, rectoceles, the uterovaginal as well as anorectal decent, intussusceptions and dyssynergic defecation should be reported using a structured report form.

CONCLUSIONS

A comprehensive analysis of all morphological and functional findings during dynamic MRI of the pelvic floor can provide information missed by other imaging modalities and hence alter therapeutic strategies.

[Dynamic magnetic resonance imaging of the pelvic floor: Technical aspects]

BACKGROUND

Dynamic magnetic resonance imaging (MRI) of the pelvic floor plays a key role in imaging complex pelvic floor dysfunction. High-quality examination is crucial for diagnostic benefit but can be technically challenging.

OBJECTIVES

The most important technical aspects (patient selection, patient preparation, MRI technology, MRI scan protocol, success control) for obtaining a state-of-the-art dynamic MRI of the pelvic floor are summarized.

MATERIALS AND METHODS

Review of the scientific literature on dynamic pelvic MR imaging with special consideration of the joint recommendations provided by the expert panels of European Society of Urogenital Radiology/European Society of Gastrointestinal and Abdominal Radiology (ESUR/ESGAR) in 2016 and Society of Abdominal Radiology (SAR) in 2019.

RESULTS

Examination with at least 1.5 T and a surface coil after rectal instillation of ultrasound gel is clinical standard. Dynamic MRI in a closed magnet with the patient in supine position is the most widespread technique. No clinically significant pathologies of the pelvic floor are missed compared to the sitting position in an open magnet. The minimum scan protocol should encompass static, high-resolution T2-imaging (i.e., T2-TSE) in three planes and dynamic sequences with high temporal resolution in sagittal (and possibly axial) plane (i.e., steady-state or balanced steady-state free precession) during squeezing, straining and evacuation. Detailed patient instruction and practicing prior to the scan improve patients' compliance and hence diagnostic quality.

CONCLUSIONS

A technically flawless dynamic MRI of the pelvic floor according to these standards can provide information missed by other imaging modalities and hence alter therapeutic strategies.

Diagnostic Value of Dynamic Magnetic Resonance Imaging (dMRI) of the Pelvic Floor in Genital Prolapses

Pelvic organ prolapse is a chronic disease resulting from a weakening of the musculoskeletal apparatus of the pelvic organs. For the diagnosis of this pathology, it is insufficient to conduct only a clinical examination. An effective diagnostic tool is the method of dynamic magnetic resonance imaging (MRI) of the pelvic floor, which allows a comprehensive assessment of the anatomical and functional characteristics of the walls of the pelvis and pelvic organs. The aim of the study was to analyze the literature data on the possibilities and limitations of using dynamic MRI in pelvic organ prolapse. The widespread use of the dynamic MRI method is due to the high quality of the resulting image, good reproducibility, and the maximum ability to display the characteristics of the pelvic floor. Dynamic MRI of the small pelvis allows a comprehensive assessment of the anatomical and functional features of the pelvis, excluding the effect of ionizing radiation on the body. The method is characterized by good visualization with high resolution and excellent soft tissue contrast. The method allows for assessing the state of the evacuation function of visualized structures in dynamics. Simultaneous imaging of all three parts of the pelvic floor using dynamic MRI makes it possible to assess multicompartment disorders. The anatomical characteristics of the state of the pelvic organs in the norm and in the event of prolapse are considered. The technique for performing the method and the procedure for analyzing the resulting images are described. The possibilities of diagnosing a multicomponent lesion are considered, while it is noted that dynamic MRI of the pelvic organs provides visualization and functional analysis of all three parts of the pelvis and often allows the choice and correction of tactics for the surgical treatment of pelvic organ prolapse. It is noted that dynamic MRI is characterized by a high resolution of the obtained images, and the advantage of the method is the ability to detect functional changes accompanying the pathology of the pelvic floor.

Investigating anorectal function using postoperative MRI-based fibrosis score in patients with locally advanced rectal cancer receiving neoadjuvant chemoradiotherapy: a two-center study

PURPOSE

This study aimed to develop a postoperative MRI-based fibrosis scoring system and to assess its correlation with anorectal function in locally advanced rectal cancer (LARC) cases administered neoadjuvant chemoradiotherapy (nCRT).

METHODS

Pathologically confirmed LARC cases administered nCRT and radical resection were assessed retrospectively. Based on postoperative magnetic resonance imaging (MRI) findings, anastomotic fibrosis score (AFS) and perirectal fibrosis score (PFS) were determined to evaluate the extent of fibrosis. The Wexner continence score for anorectal function was obtained 2 years postoperatively and assessed for correlation with MRI fibrosis scores. The cases were divided into 2 groups by the median Wexner score. Univariable and multivariable analyses were adopted for building a nomogram model, whose diagnostic performance was estimated by receiver operating characteristic (ROC) and decision curve analyses (DCA).

RESULTS

Finally, 144 patients with LARC were included in cohort 1 (training set). 52 patients were enrolled in cohort 2 (external validation set). Spearman correlation analysis indicated that AFS and PFS were positively correlated with the Wexner score. Univariable and multivariable analyses revealed age, tumor height, AFS, and PFS were independent predictors of anorectal function. The nomogram model achieved a good diagnostic performance, with AUCs of 0.800 and 0.827 in the training and validation sets, respectively; its predicting value was also confirmed by DCA.

CONCLUSION

The present study showed AFS and PFS derived from postoperative MRI are positively correlated with Wexner score. In addition, the new scoring system was effective in predicting anorectal function in LARC cases administered nCRT.

Pelvic floor dysfunction in gynecologic cancer survivors

Pelvic floor dysfunction (PFD) is a common complication in gynecologic cancer survivors (GCS) and is now a worldwide medical and public health problem because of its great impact on the quality of life of GCS. PFD after comprehensive gynecologic cancer treatment is mainly reflected in bladder function, rectal function, sexual dysfunction and pelvic organ prolapse (POP), of which different types of gynecologic cancer correspond to different disease incidence. The prevention strategies of PFD after comprehensive gynecologic cancer treatment mainly included surgical treatment, physical therapy and behavioral guidance, etc. At present, most of them still focus on physical therapy, mostly using Pelvic Floor Muscle Training (PFMT) and multi-modal PFMT treatment of biofeedback combined with electrical stimulation, which can reduce the possibility of PFD after surgery in GCS to some extent. This article reviews the clinical manifestations, causes and current research progress of prevention and treatment methods of PFD after comprehensive treatment for GCS.

Four-dimensional reconstruction and characterization of bladder deformations

BACKGROUND AND OBJECTIVE

Pelvic floor disorders are prevalent diseases and patient care remains difficult as the dynamics of the pelvic floor remains poorly understood. So far, only 2D dynamic observations of straining exercises at excretion are available in the clinics and 3D mechanical defects of pelvic organs are not well studied. In this context, we propose a complete methodology for the 3D representation of non-reversible bladder deformations during exercises, combined with a 3D representation of the location of the highest strain areas on the organ surface.

METHODS

Novel image segmentation and registration approaches have been combined with three geometrical configurations of up-to-date rapid dynamic multi-slice MRI acquisitions for the reconstruction of real-time dynamic bladder volumes.

RESULTS

For the first time, we proposed real-time 3D deformation fields of the bladder under strain from in-bore forced breathing exercises. The potential of our method was assessed on eight control subjects undergoing forced breathing exercises. We obtained average volume deviations of the reconstructed dynamic volume of bladders around 2.5% and high registration accuracy with mean distance values of 0.4 ± 0.3 mm and Hausdorff distance values of 2.2 ± 1.1 mm.

CONCLUSIONS

The proposed framework provides proper 3D+t spatial tracking of non-reversible bladder deformations. This has immediate applicability in clinical settings for a better understanding of pelvic organ prolapse pathophysiology. This work can be extended to patients with cavity filling or excretion problems to better characterize the severity of pelvic floor pathologies or to be used for preoperative surgical planning.

Longitudinal changes in pelvic organ support among primiparas with postpartum pelvic organ prolapse: A follow-up magnetic resonance imaging study

OBJECTIVE

To quantify morphological changes of pelvic floor in primiparas with postpartum pelvic organ prolapse (POP) during the early postpartum period.

METHODS

A total of 309 primiparas underwent pelvic floor magnetic resonance imaging (MRI) at 6 weeks postpartum. Those primiparas diagnosed with postpartum POP by MRI criterion were followed up at 3 and 6 months postpartum. Normal primiparas were enrolled in the control group. The puborectal hiatus line, muscular pelvic floor relaxation line, levator hiatus area, iliococcygeus angle, levator plate angle, uterus-pubococcygeal line, and bladder-pubococcygeal line were assessed on MRI. Longitudinal changes in pelvic floor measurements between the two groups were compared by repeated-measures analysis of variance.

RESULTS

Compared with the control group, enlarged puborectal hiatus line, levator hiatus area, and RICA and decreased uterus-pubococcygeal line were observed at rest in the POP group (all P < 0.05). All of the pelvic floor measurements were significantly different in the POP group compared with the control group at the maximum Valsalva maneuver (all P < 0.05). All of the pelvic floor measurements showed no significant change over time in both the POP and control groups (all P > 0.05).

CONCLUSIONS

Postpartum POP accompanied by poor pelvic floor support will persist in the early postpartum period.

A review of levator ani avulsion after childbirth: Incidence, imaging and management

Key Content • Levator ani muscle (LAM) avulsion injury occurs occultly during childbirth, most commonly during operative vaginal deliveries. • Injuries of levator ani have long term sequelae for pelvic floor health. As life expectancy increases the burden of disease upon urogynaecology services will need to be considered. • Diagnosis of this condition can be difficult as there is no agreed 'gold standard' imaging modality. • There is no consensus regarding surgical management of LAM avulsion. Learning objectives • Review anatomy and function of levator ani muscle • Identify the risk factors for levator ani avulsion injury • Role of imaging to appropriately identify LAM injury and current management options including appropriate follow up • Management of subsequent pregnancy following LAM avulsion Ethical issues • Is there value to the patient in diagnosing levator ani avulsion when there is no recommended treatment for these injuries?

Magnetic resonance imaging evaluation of the effectiveness of FemiCushion in pelvic organ prolapse

Aims

FemiCushion (FC) is a supportive device for pelvic organ prolapse (POP), but its effectiveness has not been evaluated with imaging studies. This study utilized magnetic resonance imaging (MRI) to evaluate the anatomic changes induced by FC use in patients with severe POP.

Methods

This prospective study examined patients with stage 3 or 4 POP who underwent treatment with FC and received a diagnostic MRI. Measurements were made in the midsagittal plane at rest and during straining with and without FC. The vertical distances from the lowest points of the anterior and posterior vaginal wall (A; P), uterine cervix or vaginal stump (C), and perineal body (PB) to the Pelvic Inclination Correction System line were measured, along with the lengths of the urogenital (UGH) and levator hiatus (LH).

Results

Twelve patients were included in the study. The median age was 72 (range, 56–84) years. All reference points were positioned significantly higher with the FC than without the FC (median ΔA: 11 mm, p = 0.005; ΔC: 14 mm, p = 0.011; ΔP: 6 mm, p = 0.008; ΔPB: 7 mm, p = 0.002). Median UGH and LH lengths during straining were significantly shorter with the FC than without the FC (UGH: 44 mm vs. 53 mm, p = 0.002; LH: 60 vs. 65 mm, p = 0.021).

Conclusions

This is the first report on the use of MRI to measure the performance of FC. Our study demonstrates that FC effectively repositioned the organs involved in POP.

Dynamic magnetic resonance imaging evaluation before and after operation for pelvic organ prolapse

PURPOSE

This study aimed to explore the value of dynamic magnetic resonance imaging (MRI) before and after operation for pelvic organ prolapse (POP).

METHODS

Twenty-nine patients with POP (POP group) before and one month after surgery and 12 healthy women (control group) underwent static and dynamic MRI at rest and during straining (Valsalva maneuver). The preoperative MRI images of the POP and control groups were analyzed, and various measurements were recorded. Differences in measurements were compared between the POP and control groups; similarly, changes in measurements before and after operation were compared.

RESULTS

In the POP group, MRI detected 29 anterior vaginal prolapses, 27 uterine prolapses, 1 rectoceles, and 14 pouch of Douglas hernias. In addition, 27 levator ani muscle defect and 15 pubocervical fascial defect cases were observed. The bladder-pubococcygeal line (B-PCL), uterus-pubococcygeal line (U-PCL), Douglas pouch-pubococcygeal line, the length of the hiatus, the descent of the levator plate, levator hiatus size, levator plate angle, iliococcygeus angle, and urethral inclination angle (UA) were larger in the POP group than in the control group. The pelvic organs' positions returned to normal postoperatively in 9 of 21 cases. The B-PCL, U-PCL, and UA were smaller post-surgery than pre-surgery.

CONCLUSIONS

Static and dynamic MRI can comprehensively evaluate morphological and functional changes of the pelvic floor postoperatively.

International Urogynecological Consultation: clinical definition of pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

This segment of Chapter 1 of the International Urogynecology Consultation (IUC) on pelvic organ prolapse (POP) reviews the literature on the clinical definition of POP with the intent of creating standard terminology.

METHODS

An international group containing nine urogynecologists and one university-based medical librarian performed a search of the literature using pre-specified search terms in PubMed, Embase, and Scopus. Publications were eliminated if not relevant to the clinical definition of POP, and those articles remaining were evaluated for quality using the Specialist Unit for Review Evidence (SURE). The resulting list of articles was used to inform a comprehensive review and creation of the clinical definition of POP.

RESULTS

The original search yielded 31,931 references, of which 167 were used by the writing group. Ultimately, 78 are referenced in the manuscript.

CONCLUSIONS

The clinical definition of POP for this review of the literature is: "anatomical prolapse with descent of at least one of the vaginal walls to or beyond the vaginal hymen with maximal Valsalva effort WITH the presence either of bothersome characteristic symptoms, most commonly the sensation of vaginal bulge, or of functional or medical compromise due to prolapse without symptom bother."

Clinical applications of pelvic floor imaging: opinion statement endorsed by the society of abdominal radiology (SAR), American Urological Association (AUA), and American Urogynecologic Society (AUGS)

Pelvic floor dysfunction is prevalent, with multifactorial causes and variable clinical presentations. Accurate diagnosis and assessment of the involved structures commonly requires a multidisciplinary approach. Imaging is often complementary to clinical assessment, and the most commonly used modalities for pelvic floor imaging include fluoroscopic defecography, magnetic resonance defecography, and pelvic floor ultrasound. This collaboration opinion paper was developed by representatives from multiple specialties involved in care of patients with pelvic floor dysfunction (radiologists, urogynecologists, urologists, and colorectal surgeons). Here, we discuss the utility of imaging techniques in various clinical scenarios, highlighting the perspectives of referring physicians. The final draft was endorsed by the Society of Abdominal Radiology (SAR), American Urogynecologic Society (AUGS), and the American Urological Association (AUA).

Imaging and clinical assessment of functional defecatory disorders with emphasis on defecography

Functional defecation disorders (FDD) encompass causes of constipation associated with anorectal dysfunction, which include dyssynergia or inadequate defecatory propulsion. FDD are frequently encountered in clinical practice and may affect up to 33-50% of patients with chronic constipation. The etiology of FDD is unclear, however, it has been defined as an acquired, but subliminal behavioral disorder. Pathophysiologic mechanisms may include discoordination of rectoanal muscles, paradoxical contraction or insufficient relaxation of puborectalis and/or anal sphincter during defecation, and sluggish colonic transit. A combination of comprehensive clinical assessment, digital rectal examination and a battery of physiologic tests are needed to make an accurate diagnosis of FDD. Defecography may play a crucial role in the evaluation of FDD, especially when a balloon expulsion test (BET) and/or anorectal manometry (ARM) are equivocal or demonstrate contradictory results. In this review, we provide a thorough overview of the epidemiology, pathophysiology, diagnostic criteria, clinical and imaging evaluation, and treatment options for FDD, with an emphasis on available diagnostic imaging tools such as defecography and conventional fluoroscopic methods.

MR defecography review

Pelvic floor dysfunction is a relatively common but often complex condition, presenting with a variety of clinical symptoms, especially when it involves multiple compartments. Clinical exam alone is often inadequate and requires a complementary imaging study. Magnetic resonance defecography (MRD) is an excellent noninvasive diagnostic study with its multiplanar capability, lack of ionizing radiation and excellent soft tissue resolution. It can identify both anatomic and functional abnormalities in the pelvic floor and specifically excels in its ability to simultaneously detect multicompartmental pathology and help with vital pre-operative assessment. This manuscript reviews the relevant anatomical landmarks, describes the optimal technique, highlights an approach to the interpretation of MRD, and provides an overview of the various pelvic floor disorders in the different anatomical compartments.

Multimodality imaging of pelvic floor anatomy

The pelvic floor is composed of a network of muscles, ligaments, and fasciae, which provide active and passive support for the pelvic organs. Impairment of these pelvic floor elements can result in a variety of functional abnormalities and single or multicompartment organ prolapse. Knowledge of normal pelvic floor anatomy can aid the radiologist in understanding the complex nature of pelvic floor dysfunction and is important for comprehensive image interpretation. This article provides an overview of normal anatomy of the pelvic floor as seen on magnetic resonance imaging, ultrasound, and fluoroscopic studies performed in the evaluation of pelvic floor function.

Variability in utilization and techniques of pelvic floor imaging: findings of the SAR pelvic floor dysfunction disease-focused panel

Pelvic floor disorders are common and can negatively impact quality of life. Imaging of patients with pelvic floor disorders has been extremely heterogeneous between institutions due in part to variations in clinical expectations, technical considerations, and radiologist experience. In order to assess variations in utilization and technique of pelvic floor imaging across practices, the society of abdominal radiology (SAR) disease-focused panel on pelvic floor dysfunction developed and administered an online survey to radiologists including the SAR membership. Results of the survey were compared with published recommendations for pelvic floor imaging to identify areas in need of further standardization. MRI was the most commonly reported imaging technique for pelvic floor imaging followed by fluoroscopic defecography. Ultrasound was only used by a small minority of responding radiologists. The survey responses demonstrated variability in imaging utilization, patient referral patterns, imaging protocols, patient education, and interpretation and reporting of pelvic floor imaging examinations. This survey highlighted inconsistencies in technique between institutions as well as potential gaps in knowledge that should be addressed to standardize evaluation of patients with pelvic floor dysfunction.

MR defecography technique: recommendations of the society of abdominal radiology's disease-focused panel on pelvic floor imaging

PURPOSE

To develop recommendations for magnetic resonance (MR) defecography technique based on consensus of expert radiologists on the disease-focused panel of the Society of Abdominal Radiology (SAR).

METHODS

An extensive questionnaire was sent to a group of 20 experts from the disease-focused panel of the SAR. The questionnaire encompassed details of technique and MRI protocol used for evaluating pelvic floor disorders. 75% agreement on questionnaire responses was defined as consensus.

RESULTS

The expert panel reached consensus for 70% of the items and provided the basis of these recommendations for MR defecography technique. There was unanimous agreement that patients should receive coaching and explanation of commands used during MR defecography, the rectum should be distended with contrast agent, and that sagittal T2-weighted images should include the entire pelvis within the field of view. The panel also agreed unanimously that IV contrast should not be used for MR defecography. Additional areas of consensus ranged in agreement from 75 to 92%.

CONCLUSION

We provide a set of consensus recommendations for MR defecography technique based on a survey of expert radiologists in the SAR pelvic floor dysfunction disease-focused panel. These recommendations can be used to develop a standardized imaging protocol.

Pelvic floor assessment using magnetic resonance imaging after vaginal delivery and elective caesarean delivery

INTRODUCTION AND HYPOTHESIS

We aimed to compare quantitative static and dynamic magnetic resonance imaging (MRI) measurements of pelvic floor changes during postpartum recovery from 1 week to 6 months after different modes of delivery.

METHODS

In this prospective study, 51 primiparous women (vaginal delivery group: 30 women; elective caesarean delivery group: 21 women) underwent static and dynamic MRI at 1 week, 6 weeks, 3 months, and 6 months postpartum to measure pelvic floor MRI values. Between-group differences in pelvic floor values at these time points were determined; subsequently, within-group comparisons according to time were performed. Analysis included independent samples t-tests and paired t-tests.

RESULTS

The puborectal hiatus line (H line), muscular pelvic floor relaxation line (M line), bladder-pubococcygeal line (B-PCL), and uterus-pubococcygeal line (U-PCL) differed significantly between groups during the Valsalva manoeuvre at 1 week postpartum (p < 0.05). The H line, M line, and B-PCL values differed significantly between groups during the Valsalva manoeuvre at 6 weeks postpartum (p < 0.05). There were few significant between-group differences in pelvic floor values at 3 months and 6 months postpartum. In the vaginal delivery group, the differences in the H line and M line at 1 week, 6 weeks, and 3 months postpartum were significant (p < 0.001). In the elective caesarean delivery group, U-PCL differed significantly at 6 weeks compared to 1 week postpartum during the Valsalva manoeuvre (p < 0.05).

CONCLUSIONS

Pelvic floor recovery primarily occurred during the early phase after delivery in both groups. Elective caesarean delivery had a non-significant protective effect on postpartum pelvic floor structure and function compared to vaginal delivery.

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 magnetic resonance imaging to quantify pelvic organ mobility after treatment for uterine descent: differences between surgical procedures

INTRODUCTION AND HYPOTHESIS

Pelvic organ mobility is defined as the displacement of pelvic organs between rest and maximal straining. We hypothesized that pelvic organ mobility after vaginal sacrospinous hysteropexy (SSHP) might be increased compared with other surgeries for uterine descent, which may contribute to the high occurrence of postoperative cystocele after this surgery. Pelvic organ mobility and the vaginal axes after SSHP are compared with other surgical procedures for uterine descent: vaginal hysterectomy with uterosacral suspension (VH) and laparoscopic sacrohysteropexy (LSH).

METHODS

In this prospective pilot study, 15 women were included (5 for each procedure). Six months postoperatively, POP-Q examination and dynamic MRI were performed and questionnaires were filled out regarding prolapse complaints. Pelvic organ mobility on MRI was defined as vertical displacement of pelvic organs at rest and maximal straining. The displacements and angles were measured using an image registration method. Furthermore, the angle of displacement of cervix/vaginal vault and vaginal axes were assessed.

RESULTS

No anatomical recurrences of pelvic organ prolapse were found. No difference in pelvic organ mobility was demonstrated. After VH, a more posterior position of the upper vagina was found compared with SSHP and LSH.

CONCLUSIONS

Based on these data, the higher recurrence risk in the anterior compartment after SSHP cannot be explained. Larger sample sizes, studying women with recurrence or de novo cystocele after SSHP or using an upright MRI scanner would be of interest to further assess the relationship between pelvic organ mobility and the occurrence of anterior vaginal wall prolapse.

MR defecography in the assessment of anatomic and functional abnormalities in stress urinary incontinence before and after pelvic reconstruction

PURPOSE

Magnetic resonance defecography (MRD) was used to evaluate anatomic and functional pelvic floor disorders in women with stress urinary incontinence (SUI) before and after midurethral sling (MUS) intervention.

METHOD

We performed MRD in both SUI patients and continent controls. Static MR was used to describe the anatomic abnormalities in levator ani muscle and periurethral ligaments (PUL). Dynamic MR was used to depict the function of the urethra and pelvic floor. We compared the MRD parameters between the SUI patients and continent controls before surgery. For SUI patients, dynamic MR images evaluated the functional changes of the urethra and pelvic floor after surgery.

RESULTS

In SUI group, 75.8 % have PUL defects, 65.7 % discontinuity or complete loss of pubococcygeal muscle, as compared to the continent groups (p < 0.01). There was no significant difference between the perimenopausal volunteers and SUI patients in the puborectalis defection (p > 0.05). The dynamic MR showed the urethral hypermobility, functional urethra shortening, bladder neck funneling, urethra opening and cystocele were significantly associated with SUI patients (p < 0.01). Postoperative MR indicated that SUI patients after MUS had a lower risk of bladder funneling and urethral opening at the defection phase (p < 0.01), but no significant difference in urethral hypermobility or pelvic floor prolapse was seen (p>0.05).

CONCLUSIONS

MRD with high-resolution and defecation phases provides a detailed anatomic and functional evaluation of the pelvic floor in female SUI before and after pelvic reconstruction.

Quantitative evaluation of age-related changes to pelvic floor muscles in magnetic resonance images from 369 patients

AIM

This study aimed to establish and validate a quantitative evaluation method for pelvic floor muscles using magnetic resonance images (MRI) and to examine the morphological change of pelvic floor muscles with aging.

METHODS

Data from 369 consecutive patients (163 men, 206 women; median age 58 years; range 17-92 years) who underwent coronal T2-weighted pelvic MRI at Osaka General Hospital between January 2016 and December 2016 were retrospectively examined. MRI of the levator ani muscle was evaluated. The MRI image blinded the patient information and was evaluated by a radiology specialist with 22 years of experience. In coronal T2-weighted MRI of the pelvis, the levator ani muscle was evaluated using the slice; it showed the most upward and downward convexity. We measured the thickness of the levator ani muscle, and the distance at the most convex part from a straight line connecting the origin and insertion of the levator ani muscle on both the left and right sides. Upward and downward convexity was recorded in positive and negative values, respectively.

RESULTS

The levator ani muscle was able to be evaluated quantitatively in all cases. Both men and women showed thinning (men: mean 3.316 mm, r = -0.388, P < 0.0001; women: mean 3.947 mm, r = -0.359, P < 0.0001) and concavity (men: mean 1.412 mm, r = -0.362, P < 0.0001; women: mean 4.979 mm, r = -0.630, P < 0.0001) of the levator ani muscle with aging.

CONCLUSIONS

A quantitative evaluation method for pelvic floor muscles using MRI was established. Aging was associated with morphological changes in the pelvic floor muscles in both men and women. Geriatr Gerontol Int 2019; 19: 834-837.

MRI anatomy and pathology of the anal canal

The normal function of the anal sphincter complex is crucial for quality of life, as it is the mechanism by which fecal continence is maintained. Additionally, the anal sphincter complex is an integral part of the coordinated effort of defecation. As imaging plays an important role in assessment of pathologic conditions involving the anal region, understanding the normal anatomy of the anal sphincter complex is important for correct image interpretation and accurate diagnosis. This review discusses the anatomy and function of the anal sphincter complex, important technical considerations for MRI, and various inflammatory, infectious, and neoplastic processes, as well as pathologic structural conditions that affect the anal region. Level of Evidence: 5 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;50:1018-1032.

Morphologic changes after bladder neck intussusception in laparoscopic radical prostatectomy contribute to early postoperative continence

PURPOSE

To explore the mechanism and efficacy of the modified bladder neck intussusception in laparoscopic radical prostatectomy (LSRP) on postoperative early continence.

METHODS

We prospectively collected clinical information of prostate cancer patients who underwent LSRP with modified bladder neck intussusception (n = 10) and non-intussusception (n = 10). At postoperative 1 month, the prostate-specific antigen (PSA), pad test, real-time magnetic resonance imaging (rt-MRI), and flow rate were performed. At postoperative 3 months, the PSA, pad test, international prostate symptom score (IPSS), overactive bladder symptom score (OABSS), incontinence questionnaire short form (ICI-Q-SF), and quality of life (Qol) were recorded.

RESULTS

The intussusception and non-intussusception patients had similar baseline characteristics. At postoperative 3 months, intussusception patients had lower OABSS than non-intussusception patients (P = 0.038). The non-intussusception patients suffered from more severe incontinence (P = 0.026). The continence rate of intussusception patients was significantly higher (90% vs. 20%, P = 0.005). And intussusception patients had significantly lower Qol scores (P = 0.038). According to the morphologic analysis by rt-MRI, there were 7/10 non-intussusception patients and 2/10 intussusception patients having funnel-shaped bladder necks at Valsalva movement. The intussusception patients had larger angle between anterior and posterior wall at bladder neck (P = 0.029) and longer length of functional posterior urethra (P = 0.029). During micturition, the intussusception bladder neck was found to move less dynamically on X-axis and Y-axis, but the difference did not reach significance.

CONCLUSIONS

The modified technique of bladder neck intussusception in laparoscopic radical prostatectomy prolongs the length of functional posterior urethra and is effective to improve postoperative early continence.

Use of Dynamic MRI of the Pelvic Floor in the Assessment of Anterior Compartment Disorders

PURPOSE OF REVIEW

Approximately 25% of women in the USA suffer from pelvic floor disorders. Disorders of the anterior compartment of the pelvic floor, in particular, can cause symptoms such as incomplete urinary voiding, urinary incontinence, pelvic organ prolapse, dyspareunia, and pelvic pain, potentially negatively impacting a woman's quality of life. In some clinical situations, clinical exam alone may be insufficient, especially when patient's symptoms are in excess of their pelvic exam findings. In many of these patients, dynamic magnetic resonance imaging (dMRI) of the pelvic floor can be a valuable imaging tool allowing for comprehensive assessment of the entire pelvic anatomy and its function.

RECENT FINDINGS

Traditionally, evaluation of the anterior compartment has been primarily through clinical examination with occasional use of urodynamic testing and ultrasound. In recent years, dMRI has continued to gain popularity due to its improved imaging quality, reproducibility, and ability to display the entire pelvic floor. Emerging evidence has also shown utility of dMRI in the postoperative setting. In spite of advances, there remains an ongoing discussion in contemporary literature regarding the accuracy of dMRI and its correlation with clinical examination and with patient symptoms. Dynamic pelvic MRI is a helpful adjunct to physical examination and urodynamic testing, particularly when a patient's symptoms are in excess of the physical examination findings. Evaluation with dMRI can guide preoperative and postoperative surgical management in many patients, especially in the setting of multicompartmental disorders. This review will summarize relevant pelvic floor anatomy and discuss the clinical application, imaging technique, imaging interpretation, and limitations of dMRI.