Dynamic MR imaging of the pelvic floor: a pictorial review

The usefulness of MR defecography in the evaluation of pelvic floor dysfunction: our experience using 3T MRI

PURPOSE

To assess the usefulness of MR defecography in evaluating pelvic floor dysfunction, and to correlate several pelvic organ abnormalities with each other and with patients' symptoms and characteristics.

METHODS

MR defecographic examinations performed in 3T MRI machine of 95 patients (70 females, 25 males; mean age 48) were retrospectively reviewed. Pelvic organ abnormalities from all three compartments were recorded, including the anorectal junction descent, anterior rectocele, and cystocele. These were graded according to the known HMO system in relation to the pubococcygeal line. The correlation between these different abnormalities and their relation to patient symptoms and characteristics were evaluated.

RESULTS

Anorectal junction descent and anterior rectocele were most commonly observed, predominantly manifesting in female patients. Both were associated with abnormalities from all compartments. The middle compartment was the least affected, and its abnormality of uterine/vaginal descent tended to occur in association with the anterior compartment abnormality (cystocele). Anismus was low in incidence, and was not associated with other compartments abnormalities. Both enterocele/peritoneocele and intussusception were uncommon.

CONCLUSION

MR defecography is the modality of choice in assessing pelvic floor dysfunction, because it can neatly show various pelvic organ abnormalities from all compartments in a dynamic fashion, which are frequently coexistent. It can even show clinically silent or unsuspected abnormalities which can impact the management of patients.

Paradoxical puborectalis syndrome on diffusion-weighted imaging: a retrospective study of 72 cases

This study aimed to evaluate the application value of diffusion-weighted imaging (DWI) for assessing paradoxical puborectalis syndrome (PPS) in patients with obstructive defecation syndrome (ODS). The medical records of 72 ODS patients who underwent magnetic resonance (MR)-DWI and MR-defecography were retrospectively reviewed. The differences in the apparent diffusion coefficients (ADCs) and the thickness of the right and left branches of the puborectalis muscles between the PPS(+) and PPS(−) groups were compared. In addition, the absolute within-patient differences between the right and left branches (ADC, thickness) were compared between the two groups. The absolute difference in ADCs (right branch - left branch) was significantly different between the two groups. Regardless of whether the ADC was acquired through single-ROI (0.10 ± 0.08 vs 0.23 ± 0.18, P = 0.000) or multi-ROI (0.16 ± 0.14 vs 0.27 ± 0.17, P = 0.009) analysis, the PPS(+) patients displayed a lower absolute ADC difference than did the PPS(−) patients. However, there was no statistically significant difference in the ADC value, thickness or the absolute difference in thickness between the two groups. These findings suggest that DWI may have value in quantitatively assessing the puborectalis muscle in ODS patients, whereas the value of puborectalis thickness in such aspect needs further study.

Chronic anal fissure: morphometric analysis of the anal canal at 3.0 Tesla MR imaging

OBJECTıVE: To compare the morphometric data relating to the muscular structures of the anal canal, in patients with chronic anal fissure and in control group, examined at a 3.0 Tesla MR system.

SUBJECTS AND METHODS

Forty-seven consecutive patients with chronic anal fissure and randomly selected 40 patients who had no claims for perianal disease during their life time were included in the study. T2-weighted sagittal, high-resolution (HR) T2-weighted, and contrast-enhanced fat-suppressed T1-weighted oblique axial and oblique coronal images were retrospectively analyzed by two observers in consensus. Thickness of sphincteric muscles, anal canal length, anorectal angle, thickness of anococcygeal ligament, depth of Minor triangle, width between subcutaneous sphincters, vascularity of posterior commissure, visibility of posterosuperior projection of external sphincter, and angle between the distal anal canal and posterosuperior projection of external sphincter (H angle) in patients and in controls were compared and analyzed using t test, Mann-Whitney U test, and Spearman correlation.

RESULTS

The patients with chronic anal fissure had longer anal canal (51.50 mm ± 0.91 vs. 44.11 mm ± 0.71; p = 0.000), thicker internal anal sphincter muscle at mid-anal level (4.18 ± 0.15 vs. 3.39 ± 0.07; p = 0.007), and wider space between subcutaneous external sphincters (11.39 ± 0.50 vs. 6.89 ± 0.22; p = 0.000). In patients, there was a positive correlation between H angle and external sphincter thickness at proximal (r = 0.347; p = 0.021), middle (r = 0427; p = 0.000), and distal (r = 0.518; p = 0.000)) levels of the anal canal. CONCLUSıON: 3.0 Tesla MR imaging provides detailed information about the morphometric changes in the anal sphincter muscles in patients with chronic anal fissure.

An International Urogynecological Association (IUGA) / International Continence Society (ICS) joint report on the terminology for female pelvic organ prolapse (POP)

INTRODUCTION

The terminology for female pelvic floor prolapse (POP) should be defined and organized in a clinically-based consensus Report.

METHODS

This Report combines the input of members of two International Organizations, the International Urogynecological Association (IUGA) and the International Continence Society (ICS), assisted at intervals by external referees. Appropriate core clinical categories and a sub-classification were developed to give a coding to definitions. An extensive process of fourteen rounds of internal and external review was involved to exhaustively examine each definition, with decision-making by collective opinion (consensus).

RESULTS

A Terminology Report for female POP, encompassing over 230 separate definitions, has been developed. It is clinically-based with the most common diagnoses defined. Clarity and user-friendliness have been key aims to make it interpretable by practitioners and trainees in all the different specialty groups involved in female pelvic floor dysfunction and POP. Female-specific imaging (ultrasound, radiology and MRI) and conservative and surgical managements are major additions and appropriate figures have been included to supplement and clarify the text. Emerging concepts and measurements, in use in the literature and offering further research potential, but requiring further validation, have been included as an appendix. Interval (5-10 year) review is anticipated to keep the document updated and as widely acceptable as possible.

CONCLUSION

A consensus-based Terminology Report for female POP has been produced to aid clinical practice and research.

Robot-assisted vs laparoscopic ventral rectopexy for external or internal rectal prolapse and enterocele: a randomized controlled trial

AIM

The purpose of this prospective randomized study was to compare robot-assisted and laparoscopic ventral rectopexy procedures for posterior compartment procidentia in terms of restoration of the anatomy using magnetic resonance (MR) defaecography.

METHOD

Sixteen female patients (four with total prolapse, twelve with intussusception) underwent robot-assisted ventral mesh rectopexy (RVMR) and 14 female patients (two with prolapse, twelve with intussusception) laparoscopic ventral mesh rectopexy (LVMR). Primary outcome measures were perioperative parameters, complications and restoration of anatomy as assessed by MR defaecography, which was performed preoperatively and 3 months after surgery.

RESULTS

Patient demographics, operation length, operating theatre times and length of in-hospital stay were similar between the groups. The anatomical defects of rectal prolapse, intussusception and rectocele and enterocele were similarly corrected after rectopexy in either technique as confirmed with dynamic MR defaecography. A slight residual intussusception was observed in three patients with primary total prolapse (two RVMR vs one LVMR) and in one patient with primary intussusception (RVMR) (P = 0.60). Rectocele was reduced from a mean of 33.0 ± 14.9 mm to 5.5 ± 8.4 mm after RVMR (P < 0.001) and from 24.7 ± 17.5 mm to 7.2 ± 3.2 mm after LVMR (P < 0.001) (RVMR vs LVMR, P = 0.10).

CONCLUSION

Robot-assisted laparoscopic ventral rectopexy can be performed safely and within the same operative time as conventional laparoscopy. Minimally invasive ventral rectopexy allows good anatomical correction as assessed by MR defaecography, with no differences between the techniques.

Advances in imaging diagnosis of rectocele

Rectocele is one of the common manifestations of outlet obstructive constipation. There are several imaging methods for evaluating rectocele including conventional defecography, dynamic nuclear magnetic resonance imaging (MRI) defecography and pelvic floor ultrasonography. These diagnostic techniques can identify the degree of rectocele and provide evidence for treatment. Defecography is still considered the gold standard for evaluating rectocele and guiding the operation, but it exposes patients to radiation. MRI defecography has the advantages of multi-dimensional imaging, excellent soft-tissue contrast and no radiation, and has broad prospects in the future, but it is expensive nowadays and has an unphysiological defecation way. Pelvic floor ultrasonography, especially endoanal and transperineal techniques, is able to identify all dysfunctions of the posterior pelvic floor compartment without radiation, but needs further studies.

MRI for pelvic floor dysfunction: can the strain phase be eliminated?

PURPOSE

The purpose of the study was to determine if the strain phase of an MR defecography (MRD) protocol is redundant and can be eliminated without a loss of diagnostic information.

MATERIALS AND METHODS

Institutional review board approval was obtained and the requirement for informed consent was waived. A retrospective single-center review of 80 MRD examinations (68 female, 12 male, mean age 55 years old) was conducted. Two radiologists blinded to patient information evaluated in consensus the strain and evacuation phases separately and in a random order. Each phase was assessed for the presence and degree of posterior compartment descent, cystocele, urethral hypermobility, uterovaginal prolapse, rectocele, rectal intussusception, and enterocele. The degree of pelvic floor descent was compared using a paired t test and McNemar's test was used to compare the proportion of abnormal findings.

RESULTS

The evacuation phase identified all abnormalities identified on the strain phase and also identified both additional and more pronounced abnormalities, including an additional 34 cystoceles, 20 cases of urethral hypermobility, 13 uterovaginal prolapses, 36 rectoceles, 5 rectal intussusceptions, and 6 enteroceles (all p < 0.02). The mean posterior compartment descent was 24.1 mm greater on the evacuation phase than the strain phase (p < 0.0001).

CONCLUSION

The strain phase is redundant and we propose that it can be eliminated from a routine MRD protocol. This will help streamline the examination, simplify patient instructions, and reduce both imaging and reporting time.

MR Imaging in Diagnosis of Pelvic Floor Descent: Supine versus Sitting Position

Introduction. Functional disorders of the pelvic floor represent have a significant impact on the quality of life. The advent of open-configuration systems allowed for the evaluation of defecation with MR imaging in sitting position. The purpose of the present study is to compare the results of static and dynamic pelvic MR performed in supine position versus sitting position, using a new MR prototype machine, in the diagnosis of pelvic floor descent. Materials and Methods. Thirty-one patients with pelvic floor disorders were enrolled, and underwent MR Defecography in supine position with 1.5 T closed magnet (MAGNETOM Symphony, Siemens, Germany) and in sitting position with a 0.25-Tesla open magnet system (G-Scan ESAOTE, Italy). Results. In rest and squeezing phases, positions of bladder, vagina, and ARJ were significantly different when the patient was imaged in supine versus sitting position. In the defecation phase, a significant difference for the bladder and vagina position was detected between the two exams whereas a significant difference for the ARJ was not found. A statistically significant difference exists when the pelvic floor descent is evaluated in sitting versus supine position. Conclusion. Our results show that MR Defecography in sitting position may represent a useful tool to correctly diagnose and grade the pelvic organ descent.

An International Urogynecological Association (IUGA) / International Continence Society (ICS) Joint Report on the Terminology for Female Pelvic Organ Prolapse (POP)

INTRODUCTION

The terminology for female pelvic floor prolapse (POP) should be defined and organized in a clinically-based consensus Report.

METHODS

This Report combines the input of members of two International Organizations, the International Urogynecological Association (IUGA) and the International Continence Society (ICS), assisted at intervals by external referees. Appropriate core clinical categories and a sub-classification were developed to give a coding to definitions. An extensive process of fourteen rounds of internal and external review was involved to exhaustively examine each definition, with decision-making by collective opinion (consensus).

RESULTS

A Terminology Report for female POP, encompassing over 230 separate definitions, has been developed. It is clinically-based with the most common diagnoses defined. Clarity and user-friendliness have been key aims to make it interpretable by practitioners and trainees in all the different specialty groups involved in female pelvic floor dysfunction and POP. Female-specific imaging (ultrasound, radiology and MRI) and conservative and surgical managements are major additions and appropriate figures have been included to supplement and clarify the text. Emerging concepts and measurements, in use in the literature and offering further research potential, but requiring further validation, have been included as an appendix. Interval (5-10 year) review is anticipated to keep the document updated and as widely acceptable as possible.

CONCLUSION

A consensus-based Terminology Report for female POP has been produced to aid clinical practice and research.

[Imaging for urinary incontinence]

BACKGROUND

Ultrasonography and functional cine magnetic resonance imaging (MRI) are noninvasive and x-ray free tools, which are currently widely used in clinical diagnostics and scientific research of male and female urinary incontinence. The increasing use and improving techniques of modern imaging tools are closely linked to rapid development of minimally invasive surgery in patients with urinary incontinence and insights gained in continence mechanisms.

METHODS

Whereas ultrasonography is a cost-efficient and readily available diagnostic tool for a routine use, the more expensive functional MRI, as a tool with more precise visualization of functional interactions and spatial representation of anatomical structures of the pelvic floor, is suitable for complex diagnostic purposes and scientific research. Both tools are already well established for evaluations of the female pelvic floor. For evaluation of the male pelvic floor, and in particular postprostatectomy incontinence, perineal ultrasonography and functional cine MRI are becoming increasingly evident.

CONCLUSION

Further development of both imaging tools will contribute to new insights into the continence mechanism and improve the techniques of radical prostatectomy and minimally invasive surgery of male and female urinary incontinence in the future.

MRI-based segmentation of pubic bone for evaluation of pelvic organ prolapse

Pelvic organ prolapse (POP) is a major women's health problem. Its diagnosis through magnetic resonance imaging (MRI) has become popular due to current inaccuracies of clinical examination. The diagnosis of POP on MRI consists of identifying reference points on pelvic bone structures for measurement and evaluation. However, it is currently performed manually, making it a time-consuming and subjective procedure. We present a new segmentation approach for automating pelvic bone point identification on MRI. It consists of a multistage mechanism based on texture-based block classification, leak detection, and prior shape information. Texture-based block classification and clustering analysis using K-means algorithm are integrated to generate the initial bone segmentation and to identify leak areas. Prior shape information is incorporated to obtain the final bone segmentation. Then, the reference points are identified using morphological skeleton operation. Results demonstrate that the proposed method achieves higher bone segmentation accuracy compared to other segmentation methods. The proposed method can also automatically identify reference points faster and with more consistency compared with the manually identified point process by experts. This research aims to enable faster and consistent pelvic measurements on MRI to facilitate and improve the diagnosis of female POP.

MRI defaecography in patients with faecal incontinence

AIM

Faecal incontinence (FI) requires careful assessment of its aetiology to determine the most effective treatment. The aims of this study were to evaluate MRI defaecography in FI and to compare it with clinical examination combined with rigid rectoscopy in assessing the pelvic floor in patients with FI.

METHOD

Consecutive patients with FI referred over a 3-year period to our tertiary centre for MRI defaecography were retrospectively studied. MRI images of the pelvic floor were compared with clinical examination and anuscopy and rectoscopy.

RESULTS

Seventy-four female patients [mean age 60.5 (30.0-81.0) years] were recruited. MRI defaecography showed conditions which often overlapped, including internal intussusception in 19 (25.7%) and pelvic floor descent in 24 (32.4%). There was average agreement between MRI and clinical examination for a significant anterior rectocoele (κ = 0.40) and poor agreement between MRI and anuscopy/rectoscopy for intra-rectal (κ = 0.06) and intra-anal intussusception (κ = 0.11).

CONCLUSION

Other than for anterior rectocoele, there is poor correlation between MRI defaecography and clinical examination with rigid rectoscopy. MRI can detect a variety of abnormal static and dynamic pelvic disorders. This includes enterocoele, which could result in a modification of the surgical approach to intussusception and anterior rectocoele.

Dynamic Magnetic Resonance Imaging and pelvic floor disorders: how and when?

Pelvic Floor Disorders (PFD) are a major public health problem in the world and decrease seriously the patient's quality of life. In case of recurrence after surgery or complex prolapse, imaging techniques can be used. Dynamic MRI, introduced in the early 1990s, offers information of the four compartments of the pelvis with a high resolution and a direct visualization of muscles and fascias in multiple planes. But for a practical use, such an expensive exam should be well correlated to symptoms and clinical examination or change surgical approach. The aim of our review was to precise the evidence regarding techniques, and indication of dynamic MRI in the assessment of pelvic floor disorders in daily practice. The first part is a review of available studies on methods of carrying out the dynamic MRI. The second part consists on the comparison of dynamic MRI to other assessment methods in case of pelvic floor disorders. Results emphasize the lack of strong level studies about the interest of dynamic MRI in the diagnosis and surgical management of pelvic organ prolapse. Although dynamic MRI appears highly reproducible between examiners, especially for the anterior compartment, its correlation with the degree of prolapse or the symptoms appears low. The most interesting field of application seems the detection of levator ani (LA) avulsion with a higher risk of prolapse and recidive in case of LA defects. More prospective, randomized, comparative studies have to be done.

MRI findings before and after prolapse surgery

BACKGROUND

Therapeutical outcome after prolapse surgery is evaluated using a standardized grading system based on maximum prolapse extent, which might not provide the full picture of the patient's subjective outcome. We therefore applied an evaluation method, which is detached from a grading system.

PURPOSE

To evaluate the impact of pelvic organ mobility in dynamic magnetic resonance imaging (MRI) before and after mesh-repair surgery in patients with symptomatic pelvic organ prolapse.

MATERIAL AND METHODS

To obtain measurements, we performed parasagittal T2-weighted turbo spin echo sequence at rest (TR, 3460 ms; TE, 85 ms; matrix, 512; slice thickness [ST], 5 mm), parasagittal T2-weighted true fast imaging with steady-state precession (TrueFISP) single-shot sequence during straining (TR, 397.4 ms; TE, 1.5 ms; matrix, 256; ST, 8 mm), and parasagittal T2-weighted TrueFISP sequence at maximum strain (TR, 4.3 ms; TE, 2.15 ms; matrix, 256; ST, 5 mm) at 1.5 T MRI. Pelvic organ prolapse (anatomical landmarks: bladder, cervix, pouch, rectum) was measured perpendicularly with reference to the pubococcygeal and the midpubic line. Pelvic organ mobility was defined as the difference between the measured distance at rest and at maximum strain for each anatomical landmark. All patients underwent mesh-repair procedure. Eighty patients could be included in this short-term follow-up study. Due to the physical diagnosis of pelvic organ prolapse, 51 underwent anterior mesh repair, 16 underwent posterior mesh repair, and 13 underwent total mesh repair. Surgery was performed by one surgeon, using mesh implants from several manufacturers.

RESULTS

Median values of maximum organ prolapse for bladder, cervix, pouch, and rectum preoperatively were 2.54 cm, 0.33 cm, 2.47 cm, and 0.32 cm, respectively, and 12 weeks postoperatively 0.87 cm, -1.79 cm, 1.49 cm, and 0.49 cm, respectively. Highly significant improvement (P < 0.001) of pelvic organ mobility was observed in the treated compartment at 4- and 12-week follow-up. Physical evaluation 12 weeks after mesh-repair showed an asymptomatic POP-Q stage I, if any.

CONCLUSION

Dynamic MRI is useful in visualizing the maximum extent of pelvic organ prolapse, as the evaluation of pelvic organ mobility documents the intraindividual therapeutic outcome detached from a grading system based on maximal prolapse values.

Assessment of a semiautomated pelvic floor measurement model for evaluating pelvic organ prolapse on MRI

INTRODUCTION AND HYPOTHESIS

The objective of this study was to assess the performance of a semiautomated pelvic floor measurement algorithmic model on dynamic magnetic resonance imaging (MRI) images compared with manual pelvic floor measurements for pelvic organ prolapse (POP) evaluation.

METHODS

We examined 15 MRIs along the midsagittal view. Five reference points used for pelvic floor measurements were identified both manually and using our semiautomated measurement model. The two processes were compared in terms of accuracy and precision.

RESULTS

The semiautomated pelvic floor measurement model provided highly consistent and accurate locations for all reference points on MRI. Results also showed that the model can identify the reference points faster than the manual-point identification process.

CONCLUSION

The semiautomated pelvic floor measurement model can be used to facilitate and improve the process of pelvic floor measurements on MRI. This will enable high throughput analysis of MRI data to improve the correlation analysis with clinical outcomes and potentially improve POP assessment.

Magnetic resonance imaging of pelvic floor dysfunction

Pelvic floor dysfunction is largely a complex problem of multiparous and postmenopausal women and is associated with pelvic floor or organ descent. Physical examination can underestimate the extent of the dysfunction and misdiagnose the disorders. Functional magnetic resonance (MR) imaging is emerging as a promising tool to evaluate the dynamics of the pelvic floor and use for surgical triage and operative planning. This article reviews the anatomy and pathology of pelvic floor dysfunction, typical imaging findings, and the current role of functional MR imaging.

Assessment of women with defecatory dysfunction and manual splinting using dynamic pelvic floor magnetic resonance imaging

OBJECTIVE

This study aimed to describe magnetic resonance imaging (MRI) findings in women with defecatory dysfunction who perform manual splinting.

METHODS

This is a retrospective study of 29 patients from a single urogynecology center who presented with complaints of defecatory dysfunction and who reported manual splinting to assist with bowel movements. Patients were scheduled for an MRI study with a novel "splinting" protocol to evaluate the effects of their manual splinting on the pelvic floor. The protocol involved asking patients to splint during the MRI, as they normally would when trying to defecate. The goal was to evaluate any change in pelvic anatomy and compensation for an anatomic defect that could potentially lead to their defecatory dysfunction. Magnetic resonance images of the pelvis were obtained at rest, with pelvic floor contraction, with Valsalva, and during manual splinting. These images were then reviewed by radiologists who evaluated various parameters, including anorectal angle, levator ani muscle integrity, and the presence of rectocele, cystocele, apical prolapse, and enterocele. The external and internal anal sphincters were also evaluated for continuity.

RESULTS

From September 2008 to October 2010, 29 women reported defecatory dysfunction and the need for manual splinting. Their mean (SD) age was 55.2 (10.5) years. Magnetic resonance images showed a rectocele in 86.2% of the study group, cystocele in 75.9%, enterocele in 10.3%, and a defect of the levator ani muscles in 17.2%. Twenty-one (72.4%) women had more than 1 of these defects. In addition, 27.6% had an anorectal angle less than 90 degrees or greater than 105 degrees.Patients in the study group splinted in the vagina (58.6%), on the perineum (31.0%), or on the buttock (10.3%). In all but 1 woman (96.6%), splinting improved or completely corrected the identified defect(s) as evidenced with MRI. Among those who used vaginal splinting, 52.9% of defects were corrected and 47.1% were improved. Perineal splinting corrected 55.6% and improved 33.3% of cases and was ineffective in 11.1% of cases, whereas buttock splinting corrected 33.3% and improved 66.7% of cases.

CONCLUSIONS

Most women in our study group who used manual splinting to assist in defecation are compensating for a pelvic floor defect that can be detected on MRI. Magnetic resonance imaging of the pelvis may help elucidate the etiology of the defecatory dysfunction in some women and may assist pelvic reconstructive surgeons in planning surgical correction of pelvic floor defects. Magnetic resonance imaging may also identify defects in the pelvic floor that are, at the present time, not amenable to surgical correction.

A comparative study of the sonographic appearance and anatomy of the obturator internus in normal males

The aim of this study was to compare the appearance of the normal male obturator internus on transrectal ultrasound with anatomical examination to advance the knowledge of the male pelvic muscles. This information may help to provide a new imaging method for observation of the normal male obturator internus and may facilitate the treatment of obturator internus abscesses and various other types of interventional therapies. Ten formalin-fixed male cadavers were dissected to examine the appearance and structure of the obturator internus and its relationship with the structures in close proximity. The obturator internus was also observed in five fresh male cadavers using transrectal ultrasound, after which the anatomy of the muscle was confirmed by dissection and its thickness measured. The visible fusiform was observed by sonography. The measurements of obturator internus thickness were 13.33 ± 0.32 mm on the right and 13.41 ± 0.26 mm on the left; in the formalin-fixed fresh cadaver, the measurements were 13.16 ± 0.21 mm on the right and 13.17 ± 0.22 mm on the left. Using transrectal ultrasound to recognize and observe the obturator internus is a new imaging method that will provide a foundation for the recognition of its abnormalities in the future.

Dynamic magnetic resonance imaging of pelvic organ prolapse: recent research progress

Pelvic organ prolapse (POP) refers to herniation of pelvic organs caused by the weak pelvic floor support structures. Magnetic resonance imaging (MRI) is a non-radioactive, non-invasive, fast, comprehensive, high-resolution imaging technique that has strong soft tissue contrast and can clearly show the changes of muscles and fascia structures of pelvic floor to the resting and dynamic position. It can help understand the state of pelvic organizations and provide objective imaging data for the clinical diagnosis. Dynamic MRI is commonly used for the diagnosis of bladder prolapse and swelling, uterine and vaginal prolapse, rectal prolapse and enterocele. Currently, there are no unified diagnostic criteria for POP in China. Although the US HMO system is frequently used for assessing the degree of POP, it needs to be further explored whether this system is fit for the Chinese population. In short, dynamic MRI permits a comprehensive evaluation of pelvic organ prolapse. It is an important way to study the living anatomy, shape and movement of pelvic floor. In addition to clinical evaluations, dynamic MRI (especially dynamic MRI defecography) plays a role in guiding the interdisciplinary treatment of pelvic floor dysfunction.

Feasibility of diffusion tensor imaging (DTI) with fibre tractography of the normal female pelvic floor

Objectives

To prospectively determine the feasibility of diffusion tensor imaging (DTI) with fibre tractography as a tool for the three-dimensional (3D) visualisation of normal pelvic floor anatomy.

Methods

Five young female nulliparous subjects (mean age 28 ± 3 years) underwent DTI at 3.0T. Two-dimensional diffusion-weighted axial spin-echo echo-planar (SP-EPI) pulse sequence of the pelvic floor was performed, with additional T2-TSE multiplanar sequences for anatomical reference. Fibre tractography for visualisation of predefined pelvic floor and pelvic wall muscles was performed offline by two observers, applying a consensus method. Three eigenvalues (λ1, λ2, λ3), fractional anisotropy (FA) and mean diffusivity (MD) were calculated from the fibre trajectories.

Results

In all subjects fibre tractography resulted in a satisfactory anatomical representation of the pubovisceral muscle, perineal body, anal - and urethral sphincter complex and internal obturator muscle. Mean FA values ranged from 0.23 ± 0.02 to 0.30 ± 0.04, MD values from 1.30 ± 0.08 to 1.73 ± 0.12 × 10⁻³ mm²/s. Muscular structures in the superficial layer of the pelvic floor could not be satisfactorily identified.

Conclusions

This study demonstrates the feasibility of visualising the complex three-dimensional pelvic floor architecture using 3T-DTI with fibre tractography. DTI of the deep female pelvic floor may provide new insights into pelvic floor disorders.

Dynamic magnetic resonance imaging and transperineal sonography in the assessment of patients presenting primarily with evacuatory difficulty: a short position paper

Patients presenting with primary evacuatory difficulty have a multiplicity of pelvic floor and perineal soft tissue anomalies. The radiological assessment of these patients requires modalities which monitor the dynamic interaction of pelvic organs during provocative manoeuvres such as straining and simulated defaecation. The advantages and disadvantages of these complementary modalities, (dynamic magnetic resonance imaging, dynamic transperineal sonography and dynamic 2- and 3-dimensional endoanal sonography) are provided in this position paper.