MRI of the Male Pelvic Floor

Off the wall: incidental paraspinal and pelvic muscle pathology on abdominopelvic imaging

As the use of cross-sectional abdominal and pelvic imaging has increased exponentially in the past several decades, incidental musculoskeletal findings have become commonplace. These are often unrelated to the indication for the examination and are frequently referred to as the "radiologist's blind spot" on these studies. The differential diagnosis for abnormalities of the paraspinal and pelvic musculature is, in many cases, quite different from the anterior abdominal wall muscles. Furthermore, due to their relatively deep location, pathology involving the former muscle groups is more likely to be clinically occult, often presenting only incidentally when the patient undergoes cross-sectional imaging. Effective treatment of diseases of these muscles is dependent on adherence to a diverse set of diagnostic and treatment algorithms. The purpose of this review article is to familiarize the radiologist with the unique pathology of these often-overlooked muscles of the abdomen and pelvis.

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.

GI factors, potential to predict prostate motion during radiotherapy; a scoping review

Purpose

A scoping literature review was conducted to identify gastrointestinal (GI) factors most likely to influence prostate motion during radiotherapy. We proffer that patient specific measurement of these GI factors could predict motion uncertainty during radiotherapy, facilitating personalised care by optimising treatment technique e.g., daily adaption or via bespoke patient pre-habilitation and preparation.

Methods

The scoping review was undertaken as per JBI guidelines. Searches were conducted across four databases: Ovid Medline®, EMBASE, CINAHL and EBSCO discovery. Articles written in English from 2010-present were included. Those pertaining to paediatrics, biological women exclusively, infectious and post-treatment GI morbidity and diet were excluded.Common GI factors impacting men were identified and related symptoms, incidence and measurement tools examined. Prevalence among persons with prostate cancer was explored and suitable assessment tools discussed.

Results

A preliminary search identified four prominent GI-factors: mental health, co-morbidity and medication, physical activity, and pelvic floor disorder. The scoping search found 3644 articles; 1646 were removed as duplicates. A further 1249 were excluded after title and abstract screening, 162 remained subsequent to full text review: 42 mental health, 53 co-morbidity and medication, 39 physical activity and 28 pelvic floor disorder.Six GI factors prevalent in the prostate cancer population and estimated most likely to influence prostate motion were identified: depression, anxiety, diabetes, obesity, low physical activity, and pelvic floor disorder. Reliable, quick, and easy to use tools are available to quantify these factors.

Conclusion

A comprehensive GI factor assessment package suitable to implement into the radiotherapy clinic has been created. Unveiling these GI factors upfront will guide improved personalisation of radiotherapy.

Comparing male and female pelvic floor muscle function by the number and type of pelvic floor symptoms

AIMS

Pelvic floor symptoms (PFS), including lower urinary tract symptoms, defecation problems, sexual dysfunction, and pelvic pain, are common in males and females. Comparing pelvic floor musculature (PFM) function between sexes may reveal important differences relevant to clinical care. This study aimed to compare male and female PFM function and to assess the function of both sexes with the number and type of PFS.

METHODS

We purposively enrolled males and females aged ≥ 21 years with 0-4 PFS based on questionnaire responses in an observational cohort study. Participants then underwent PFM assessment, and muscle function in the external anal sphincter (EAS) and puborectal muscle (PRM) were compared between sexes. The relationships between muscle function and the number and type of PFS were explored.

RESULTS

Of the invited 400 males and 608 females, 199 and 187 underwent PFM assessment, respectively. Compared with females, males more often showed increased EAS and PRM tone during assessments. Compared with males, females more often showed weaker maximum voluntary contraction (MVC) of the EAS and dysfunctional endurance of both muscles; additionally, those with zero or one PFS, sexual dysfunction, and pelvic pain more often showed a weak MVC of the PRM.

CONCLUSIONS

Despite a few similarities between males and, females we found differences in muscle tone, MVC, and endurance between male and female PFM function. These findings provide useful insights into the differences in PFM function between males and females.

The variation in shape and thickness of the pelvic floor musculature in males and females: a geometric-morphometric analysis

INTRODUCTION AND HYPOTHESIS

In women, the risk of pelvic floor prolapse is known to be associated with age and parity. Different studies suggested that it is also related to pelvic dimensions, e.g. biomechanical modelling showed that a larger pelvic canal results in higher values of displacement, stress and strain in the pelvic floor muscles, which can increase the risk of pelvic floor disorders. To better understand the multiple factors contributing to pelvic floor disorders, we assessed how age, body weight, body height, parity (in women), pelvic canal size and overall muscle development affected pelvic floor geometry.

METHODS

A comprehensive geometric morphometric analysis of variation in pelvic floor muscle shape was conducted based on a dense set of 3D landmarks measured on CT scans in a cohort of 49 deceased men and 52 deceased women. The multivariate association between biological variables (parity, dimensions of the true pelvis, age, body weight, height) and pelvic floor muscle morphology was explored by reduced rank regression in both sexes.

RESULTS

In women, advanced age, high body weight relative to body height and a large pelvic canal were associated with a deeper pelvic floor. Surprisingly, parity did not have any strong association with overall pelvic floor shape. In men, high body weight was associated with a deep pelvic floor. Age had little effect on male pelvic floor shape, except for the thickness of the ischiocavernosus muscle, which reduced with age.

CONCLUSION

These results suggest that age, relative body weight and the size of the pelvic canal contribute to the risk of female pelvic floor disorders via their effect on pelvic floor shape, independently of birth-related factors such as injury and avulsion of pelvic floor muscles.

Exploring pelvic floor muscle function in men with and without pelvic floor symptoms: A population-based study

BACKGROUND

Pelvic floor symptoms (PFS), such as lower urinary tract symptoms, defecation disorders, sexual problems, and genital-pelvic pain, are prevalent in men. Thorough physical assessments of the external anal sphincter (EAS) and the puborectal muscle (PRM) are the keys to unraveling the role of muscle dysfunction.

OBJECTIVES

To explore associations within and between the EAS and PRM and between muscle (dys-) function and the number of male PFS.

METHODS

This cross-sectional study purposively enrolled men aged ≥21 years with 0-4 symptoms from a larger study. After extensive external and internal digital pelvic floor assessment, we explored (1) agreement between muscle function of the EAS versus PRM (using cross tabulation), (2) associations within and between the EAS and PRM (using heatmaps), and (3) associations between muscle function and number of PFS (using a visual presentation [heatmaps] and χ²  tests).

RESULTS

Overall, 42 out of 199 men (21%) had completely normal muscle function. Sixty-six (33.2%) had no symptoms, of which 53 (80%) had some degree of muscle dysfunction. No clear dose-response relationship existed between muscle (dys-) function and the number of symptoms. The PRM showed both more dysfunction and severer dysfunction than the EAS.

CONCLUSIONS

No clear association exists between muscle dysfunction and the number of symptoms, and the absence of PFS does not indicate normal muscle function for all men. Dysfunction levels are highest for the PRM. Further pelvic floor muscle research is warranted in men with PFS.

Exploring concomitant pelvic floor symptoms in community-dwelling females and males

OBJECTIVES

Researchers and clinicians tend to focus on one pelvic floor symptom (PFS) at the time. However, the pelvic floor acts as one functional unit, increasing the likelihood of concurrent PFS in patients with pelvic floor dysfunction. There is also a paucity of literature on the prevalence of concomitant PFS, especially in males. Therefore, we explored the occurrence of concomitant PFS in community-dwelling males and females.

MATERIALS AND METHODS

This prospective observational population-based cohort study included males and females aged ≥16 years from a single Dutch municipality. Participants completed validated questionnaires on lower urinary tract symptoms (LUTS), defecation problems, sexual dysfunction, pelvic pain, and pelvic organ prolapse. Medical general practitioner records were examined. Furthermore, a randomly selected group of non-responders aged <80 years received a short questionnaire, to study response bias.

RESULTS

We invited 11 724 people, among which 839 females and 566 males completed the questionnaires. Of the female participants, 286 (34.1%) reported no PFS, and 251 (29.9%) reported two or more PFS. The most prevalent PFS clusters in females were sexual dysfunction and pelvic pain, sexual dysfunction and defecation problems, LUTS and defecation problems, and LUTS, defecation problems, and pelvic pain. Of the male participants, 212 (37.5%) reported no PFS, and 191 (33.7%) reported two or more PFS. The most prevalent clusters in males were sexual dysfunction and LUTS, defecation problems and LUTS, and sexual dysfunction, LUTS, and defecation problems.

CONCLUSION

A considerable overlap existed between PFS, with differences in PFS clusters between females and males. Of note, females reported pelvic pain more than males. We conclude that healthcare providers should address all PFS in males and females.

Imaging of the Bulbourethral (Cowper) Gland: Abnormalities and Differential Diagnosis

Normal Cowper glands and ducts are imperceptible at imaging. However, abnormalities of the Cowper glands and ducts are increasingly seen owing to increasing use of cross-sectional imaging. In this article, the authors present a comprehensive review of the normal anatomy of the Cowper glands and ducts and the clinical and imaging findings of conditions that affect them in an effort to help lead to appropriate diagnosis and management. A Cowper duct syringocele is a congenital or acquired dilatation of the Cowper duct in the bulb of the corpus spongiosum. Retrograde urethrography is the standard test to diagnose a communicating (open) Cowper duct syringocele, and MRI is used for further morphologic assessment. Cowperitis refers to inflammation of the gland and/or duct, and recurrent cowperitis is usually associated with an underlying syringocele, a urethral fistulous connection to the Cowper gland, or a perianal fistula. MRI allows detection of the underlying structural abnormality and the superimposed inflammation. Cowper stones are typically radiopaque and are found in both the Cowper gland and duct. A Cowper gland HHhemorrhagic cyst may be incidentally detected at MRI of the prostate, and follow-up MRI may be required to ensure evolution of hemorrhage and exclude an underlying neoplasm. Cowper gland carcinoma is rare and includes adenocarcinoma and adenoid cystic carcinoma subtypes. Transperineal US may be used for initial evaluation and CT and/or MRI are necessary for further characterization and staging. Cowper gland hyperplasia is a rare entity with few previous reports that may be incidentally detected at imaging and may mimic malignancy. ^©RSNA, 2022.

Evaluation of Nursing Effect of Pelvic Floor Rehabilitation Training on Pelvic Organ Prolapse in Postpartum Pregnant Women under Ultrasound Imaging with Artificial Intelligence Algorithm

This study was aimed at exploring the application value of ultrasound technology and rehabilitation training based on artificial intelligence algorithm in postpartum recovery of pelvic organ prolapse. Sixty patients diagnosed as mild and moderate pelvic organ prolapse by pelvic organ prolapse quantification evaluation were selected as the research objects. The patients were randomly divided into experimental group (30 cases) and control group (30 cases). The patients in the control group were given routine guidance and postpartum health education 42 days after delivery and given no pelvic floor rehabilitation training, waiting for natural recovery. 42 days after delivery, the patients in the experimental group received pelvic floor rehabilitation training based on the patients in the control group. All patients underwent ultrasonography, the convolution neural network (CNN) algorithm was used for image denoising and edge feature extraction, and the performance of the algorithm was evaluated by the Dice coefficient, positive predictive value, sensitivity, and Hausdorff distance. The thickness of levator ani muscle, anterior and posterior diameter of perineal hiatus, pelvic floor muscle strength, and imaging data were compared between the two groups. The results revealed that the thickness of levator ani muscle in the experimental group was significantly greater than that in the control group after one month and three months of treatment (0.633 ± 0.26 cm vs. 0.519 ± 0.234 cm, 0.7 ± 0.214 cm vs. 0.507 ± 0.168 cm, P < 0.05). After one month and three months of treatment, the anterior and posterior diameter of perineal fissure in the experimental group was obviously smaller than that in the control group (4.76 ± 0.513 cm vs. 5.002 ± 0.763 cm, 4.735 ± 0.614 cm vs. 4.987 ± 0.581 cm, P < 0.05). The pelvic floor muscle strength of the experimental group was remarkably higher than that of the control group after one month and three months of treatment (3.183 ± 1.47 vs. 2.41 ± 1.57, 3.365 ± 1.53 vs. 2.865 ± 1.69, P < 0.05). The ultrasonic image was clearer, the focus was more prominent, and the image quality was significantly improved after being processed by artificial intelligence algorithm. The Dice coefficient, positive predictive value, sensitivity, and Hausdorff distance of the proposed algorithm were better than those of the traditional algorithm. Thus, artificial intelligence algorithm had a good effect in ultrasonic image processing. Pelvic floor rehabilitation training had a good effect on postpartum nursing of patients with pelvic organ prolapse.

Systematic review and meta-analysis of the outcome of puborectalis division in the treatment of anismus

AIM

Anismus is a common cause of obstructed defaecation syndrome (ODS). The aim of the present review is to assess the efficacy and safety of puborectalis muscle (PRM) division in the treatment of anismus.

METHOD

PubMed, Scopus, Web of Science and the Cochrane Library were searched for studies that assessed the outcome of PRM division in the treatment of anismus. The main outcome measures were subjective improvement in ODS, decrease in the Wexner constipation score and ODS score, and complications, namely faecal incontinence (FI).

RESULTS

Ten studies (204 patients, 63.7% male) were included. The weighted mean rate of initial subjective improvement across randomized trials was 97.6% (95% CI 94%-100%) and across nonrandomized studies it was 63.1 (95% CI 39.3%-87%). The weighted mean rate of 12-month improvement across randomized trials was 64.9% (95% CI 53.3%-76.4%) and across nonrandomized studies it was 55.9% (95% CI 30.8%-81%). The weighted mean rate of FI across randomized trials was 12.1% (95% CI 4.2%-20%) and across nonrandomized studies it was 10.4% (95% CI 1.6%-19.3%). Male sex and unilateral PRM division were significantly associated with recurrence of symptoms after PRM division. Bilateral PRM division, posterior division, complete division and concomitant sphincterotomy were significantly associated with FI after PRM division.

CONCLUSIONS

The use of PRM division for treatment of anismus was followed by some initial improvement in ODS symptoms which decreased to <60% 12 months after PRM division. The mean rate of FI after PRM division, namely 10%-12%, is a limitation of the technique. Further well-designed trials are needed to verify the outcome of PRM division in the treatment of anismus.