MR defecography review

MR defecography in assessing stress urinary incontinence with or without symptomatic pelvic organ prolapse

PURPOSE

Utilize magnetic resonance defecography (MRD) to analyze the primary pelvic floor dysfunctions in patients with stress urinary incontinence (SUI) associated with pelvic organ prolapse (POP), and in SUI patients with asymptomatic POP.

METHOD

We performed MRD in both SUI and POP subjects. As a primary analysis, the functional MR parameters were compared between the isolated POP and POP combined SUI groups. As a secondary analysis, the functional MR data were compared between the POP combined SUI and the SUI with asymptomatic POP (isolated SUI) groups.

RESULTS

MRD noted the main characteristics of SUI combined moderate or severe POP, including the shorter closed urethra length (1.87 cm vs. 2.50 cm, p < 0.001), more prevalent urethral hypermobility (112.31° vs. 85.67°, p = 0.003), bladder neck funneling (48.28% vs. 20.51%, p = 0.020), lower position of vesicourethral junction (2.11 cm vs. 1.67 cm, p = 0.030), and more severe prolapse of the posterior bladder wall (6.26 cm vs. 4.35 cm, p = 0.008). The isolated SUI patients showed the shortest length of the closed urethra (1.56 cm vs. 1.87 cm, p = 0.029), a larger vesicourethral angle (153.80° vs. 107.58°, p < 0.001), the more positive bladder funneling (84.85% vs. 48.28%, p = 0.002) and a special urethral opening sign (45.45% vs. 3.45%, p < 0.001).

CONCLUSIONS

Patients with SUI accompanying POP primarily exhibit excessive urethral mobility and a shortened urethral closure. SUI patients with asymptomatic POP mainly show dysfunction of the urethra and bladder neck, characterized by the opening of the urethra and bladder neck and a shortened urethral closure.

Imaging in pediatric disorders of the gut-brain interactions: current best practice and future directions

INTRODUCTION

Disorders of Gut-Brain Interactions (DGBI) are a common clinical problem in children and pose significant challenges to the attending pediatrician. Radiological investigations are commonly ordered to evaluate these children.

AREA COVERED

This review focuses on the current best practice of using radiological investigations in DGBIs and how novel radiological investigations could revolutionize the assessment and therapeutic approach of DGBI in children.

EXPERT OPINION

We believe imaging in DGBI is still in its early stages, but it has the potential to revolutionize how we diagnose and treat children with DGBI. As the understanding of the gut-brain axis continues to grow, we can expect to see the disappearance of conventional imaging techniques and the emergence of more sophisticated imaging techniques with less radiation exposure in the future which provide more clinically meaningful information regarding the gut-brain axis and its influence on intestinal function. Some of the novel imaging modalities will be able to broaden our horizon of understanding DGBI in children providing more useful therapeutic options to minimize their suffering.

[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.

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.

X-ray video defaecography is superior to magnetic resonance defaecography in the imaging of defaecation disorders

AIM

The aim of this work was to study the technical success and diagnostic capability of magnetic resonance defaecography (MRD) compared with video defaecography (VD).

METHOD

Sixty four women with defaecation disorders underwent both MRD and x-ray VD over 1 year. The assessment by two radiologists in consensus was retrospective and blinded. The technical success of straining and evacuation was evaluated subjectively. The presence of enterocele, intussusception, rectocele and dyssynergic defaecation was analysed according to established criteria, with VD as the standard of reference.

RESULTS

It was found that 62/64 (96.9%) VD studies were technically fully diagnostic compared with 29/64 (45.3%) for MRD. The number of partially diagnostic studies was 1/64 (1.6%) for VD versus 21/64 (32.8%) for MRD, with 1/64 (1.6%) (VD) and 14/64 (21.9%) (MRD) being nondiagnostic. Thirty enteroceles were observed by VD compared with seven in MRD with moderate agreement (κ = 0.41). Altogether 53 intussusceptions were observed by VD compared with 27 by MRD with poor agreement (κ = -0.10 and κ = 0.02 in recto-rectal and recto-anal intussusception, respectively). Moderate agreement (κ = 0.47) was observed in diagnosing rectocele, with 47 cases by VD and 29 by MRD. Dyssynergic defaecation was observed in three patients by VD and in 11 patients by MRD, with slight agreement (κ = 0.14).

CONCLUSION

The technical success and diagnostic capabilities of VD are better than those of MRD. VD remains the method of choice in the imaging of defaecation disorders.

Defecating proctography: A pictorial essay

OBJECTIVES

To provide an illustrative description of the technique and spectrum of findings in defecating proctography.

KEY FINDINGS

Important findings on defecating proctography include rectocoele, enterocoele, sigmoidocoele, cystocoele, intussusception, rectal prolapse, descending perineum, incomplete emptying, anismus, and faecal incontinence. This review article illustrates these key findings with examples.

CONCLUSION

Defecating proctography is a well-established and cost-effective method of assessing disordered defecation. In conjunction with clinical information and other diagnostic tests, findings on defecating proctography can guide appropriate multidisciplinary management and may lead to improvement in embarrassing and debilitating symptoms in many patients.

IMPLICATIONS FOR PRACTICE

This review article provides a suggested technique and covers the spectrum of findings on defecating proctography.

Magnetic resonance imaging evaluation of pelvic floor structure during pregnancy

OBJECTIVE

Among the various risk factors of pelvic floor disorders, pregnancy has been reported to affect the pelvic floor structure; however, not all these effects have been understood yet. The aim of this study is to elucidate how pregnancy affects pelvic floor structure via magnetic resonance imaging (MRI).

STUDY DESIGN

We conducted a retrospective study between January 2010 and December 2019 to extract clinical records of pregnant and non-pregnant women, who underwent MRI for obstetrical diseases and ovarian benign tumors, respectively. The data on age, body mass index (BMI), complications, gravida, parity, gestational age, and obstetrical history were collected, and pubo-coccygeal line (PCL), pubo-rectal line (PRL), and M line (ML) on their MR images were measured. Statistical analyses were performed with Wilcoxon test, chi-square test, and Kruskal-Wallis test with Steel-Dwass post hoc test as appropriate. Statistical significance was set at P < 0.05.

RESULTS

We analyzed the reports of 56 (pregnancy group) and 106 women (non-pregnancy group). There was no significant difference in age or BMI, while the obstetric history was significantly different between these groups. Median PCL, PRL, and ML in the pregnancy group were significantly longer than those in the non-pregnancy group (114.1 mm vs. 110.0 mm, P = 0.018; 48.6 mm vs. 41.6 mm, P < 0.0001 and 21.7 mm vs. 10.0 mm, p < 0.0001. respectively). The subgroup analysis of the effect of pregnancy and vaginal delivery (VD) history on changes in these lines revealed that pregnancy-induced PRL increase tended to recover to the reference level of "non-pregnant without VD," but ML increase did not fully recover.

CONCLUSION

MRI revealed a strong effect of pregnancy on pelvic floor structure.

Meshy business: MRI and ultrasound evaluation of pelvic floor mesh and slings

Pelvic floor disorders are a complex set of conditions including but not limited to stress urinary incontinence and pelvic organ prolapse that generally affect older and multiparous women. Of the several surgical options available for treatment of these conditions, synthetic mid-urethral slings for stress urinary incontinence and vaginal mesh for pelvic organ prolapse are amenable to imaging evaluation by ultrasound and magnetic resonance imaging techniques. Ultrasound can evaluate the sub- and immediate peri-urethral portions of sling due to its ability to differentiate synthetic material from native tissues with real-time imaging, while MRI is able to better depict the global pelvic floor anatomy and assess the more distant components of mesh and slings material. Given the high prevalence of pelvic floor disorders and complications after surgical repair, it is important that radiologists familiarize themselves with normal and abnormal imaging findings after these procedures. This article provides a review of the spectrum of imaging findings in patients after pelvic floor repair with synthetic mid-urethral slings and vaginal mesh.

Anorectal Physiology Testing for Prolapse-What Tests are Necessary?

Rectal prolapse frequently occurs in conjunction with functional and anatomic abnormalities of the bowel and pelvic floor. Prolapse surgery should have as its goal not only to correct the prolapse, but also to improve function to the greatest extent possible. Careful history-taking and physical exam continue to be the surgeon's best tools to put rectal prolapse in its functional context. Physiologic testing augments this and informs surgical decision-making. Defecography can identify concomitant middle compartment prolapse and pelvic floor hernias, potentially targeting patients for urogynecologic consultation or combined repair. Other tests, including manometry, ultrasound, and electrophysiologic testing, may be of utility in select cases. Here, we provide an overview of available testing options and their individual utility in rectal prolapse.