An Overview of the Effect of Aging on the Female Urethra.

Urethral function declines by roughly 15% per decade and profoundly contributes to the pathogenesis of urinary incontinence. Individuals with poor urethral function are more likely to fail surgical management for stress incontinence that focus on improving urethral support. The reduced number of intramuscular nerves and the morphologic changes in muscle and connective tissue collectively impact urethral function as women age. Imaging technologies like MRI and ultrasound have advanced our understanding of these changes. However, substantial knowledge gaps remain. Addressing these gaps can be crucial for developing better prevention and treatment strategies, ultimately enhancing the quality of life for aging women.

Safety and efficacy of fluoroscopy-guided urethral catheterization in case of failed blind or cystoscopy-assisted urethral catheterization.

This retrospective study evaluated the safety and efficacy of fluoroscopy-guided urethral catheterization in patients who failed blind or cystoscopy-assisted urethral catheterization. We utilized our institutional database between January 2011 and March 2023, and patients with failed blind or cystoscopy-assisted urethral catheterization and subsequent fluoroscopy-guided urethral catheterization were included. A 5-Fr catheter was inserted into the urethral orifice, and the retrograde urethrography (RGU) was acquired. Subsequently, the operator attempted to pass a hydrophilic guidewire to the urethra. If the guidewire and guiding catheter could be successfully passed into the bladder, but the urethral catheter failed pass due to urethral stricture, the operator determined either attempted again with a reduced catheter diameter or performed balloon dilation according to their preference. Finally, an appropriately sized urethral catheter was selected, and an endhole was created using an 18-gauge needle. The catheter was then inserted over the wire to position the tip in the bladder lumen and ballooned to secure it. We reviewed patients' medical histories, the presence of hematuria, and RGU to determine urethral abnormalities. Procedure-related data were assessed. Study enrolled a total of 179 fluoroscopy-guided urethral catheterizations from 149 patients (all males; mean age, 73.3 ± 13.3 years). A total of 225 urethral strictures were confirmed in 141 patients, while eight patients had no strictures. Urethral rupture was confirmed in 62 patients, and hematuria occurred in 34 patients after blind or cystoscopy-assisted urethral catheterization failed. Technical and clinical success rates were 100%, and procedure-related complications were observed in four patients (2.2%). The mean time from request to urethral catheter insertion was 129.7 ± 127.8 min. The mean total fluoroscopy time was 3.5 ± 2.5 min and the mean total DAP was 25.4 ± 25.1 Gy cm2. Balloon dilation was performed in 77 patients. Total procedure time was 9.2 ± 7.6 min, and the mean procedure time without balloon dilation was 7.1 ± 5.7 min. Fluoroscopy-guided urethral catheterization is a safe and efficient alternative in patients where blind or cystoscopy-assisted urethral catheterization has failed or when cystoscopy-urethral catheterization cannot be performed.

Update on imaging recommendations in paediatric uroradiology: the European Society of Paediatric Radiology workgroup session on voiding cystourethrography.

Voiding cystourethrography (VCUG) is a fluoroscopic technique that allows the assessment of the urinary tract, including the urethra, bladder, and-if vesicoureteral reflux (VUR) is present-the ureters and the pelvicalyceal systems. The technique also allows for the assessment of bladder filling and emptying, providing information on anatomical and functional aspects. VCUG is, together with contrast-enhanced voiding urosonography (VUS), still the gold standard test to diagnose VUR and it is one of the most performed fluoroscopic examinations in pediatric radiology departments. VCUG is also considered a follow-up examination after urinary tract surgery, and one of the most sensitive techniques for studying anatomy of the lower genitourinary tract in suspected anatomical malformations. The international reflux study in 1985 published the first reflux-protocol and graded VUR into five classes; over the following years, other papers have been published on this topic. In 2008, the European Society of Paediatric Radiology (ESPR) Uroradiology Task Force published the first proposed VCUG Guidelines with internal scientific society agreement. The purpose of our work is to create a detailed overview of VCUG indications, procedural recommendations, and to provide a structured final report, with the aim of updating the 2008 VCUG paper proposed by the European Society of Paediatric Radiology (ESPR). We have also compared VCUG with contrast-enhanced VUS as an emergent alternative. As a result of this work, the ESPR Urogenital Task Force strongly recommends the use of contrast-enhanced VUS as a non-radiating imaging technique whenever indicated and possible.

Routine Imaging After Bulbar Urethral Reconstruction Does Not Impact Surgical Outcomes and May Not Be Necessary.

OBJECTIVE: To assess whether omitting routine post-operative imaging adversely impacts clinical outcomes after bulbar urethroplasty. Contrast imaging is commonly performed prior to catheter removal after urethroplasty but the clinical need for this is unclear. METHODS: This was a matched, case-control analysis comparing patients undergoing routine voiding cystourethrogram (VCUG) prior to catheter removal after bulbar urethroplasty to patients without imaging. Patients were matched with respect to age, stricture etiology, length, and urethroplasty technique. Follow-up consisted of clinical assessment 3 weeks post-operatively for VCUG/catheter removal, cystoscopy at 3-4 months with clinical assessment annually. Outcome measures were 90-day complications (Clavien ≥2) and stricture recurrence (failure to pass a 16-Fr flexible cystoscope on follow-up). Chi-square and Kaplan-Meier analysis were conducted where appropriate. RESULTS: Hundred patients undergoing bulbar urethroplasty with VCUG prior to catheter removal were compared to 100 matched case controls without imaging. Groups did not differ with respect to failed endoscopic treatment (P = .82), prior urethroplasty (P = .09), comorbidities (P = .54), smoking (P = .42), or pre-operative bacteriuria (P = 1.00). The incidence of extravasation in the VCUG group was 2%. Overall 90-day complications were 9.5% and 15 patients developed recurrence with a median follow-up of 174 months. On chi-square analysis, 90-day complications did not differ between patients undergoing VCUG and those without (12% vs 7.0%; P = .34). On log-rank analysis, stricture recurrence did not differ between groups (P = .44). CONCLUSION: Routine imaging with VCUG after bulbar urethroplasty does not influence the risk of post-operative complications or stricture recurrence. Surgeons should consider avoiding this potentially unnecessary examination in routine clinical practice.

Obstructing urethral membrane in a girl: a rare cause of female bladder outlet obstruction.

Bladder outlet obstruction is known to produce back pressure changes on the urinary tract with devastating sequelae more often than not. Among the causes, posterior urethral valve, which is the most common, is documented to occur exclusively in males. Female posterior urethral valves have been reported in the past in less than 25 cases in existing literature. We discuss the case of a female toddler who presented with symptoms of straining to void and recurrent urinary tract infections. On evaluation, she was found to have an obstructing urethral membrane causing bladder outlet obstruction, which was endoscopically ablated with success.

Ultrasound imaging of male urethral stricture disease: a narrative review of the available evidence, focusing on selected prospective studies.

PURPOSE: To synthetize the current scientific knowledge on the use of ultrasound of the male urethra for evaluation of urethral stricture disease. This review aims to provide a detailed description of the technical aspects of ultrasonography, and provides some indications on clinical applications of it, based on the evidence available from the selected prospective studies. Advantages and limitations of the technique are also provided. METHODS: A comprehensive literature search was performed using the Medline and Cochrane databases on October 2022. The articles were searched using the keywords "sonourethrography", "urethral ultrasound", "urethral stricture" and "SUG". Only human studies and articles in English were included. Articles were screened by two reviewers (M.F. and K.M.). RESULTS: Our literature search reporting on the role of sonourethrography in evaluating urethral strictures resulted in selection of 17 studies, all prospective, even if of limited quality due to the small patients' number (varied from 28 to 113). Nine studies included patients with urethral stricture located in anterior urethra and eight studies included patients regardless of the stricture location. Final analysis was based on selected prospective studies, whose power was limited by the small patients' groups. CONCLUSION: Sonourethrography is a cost-effective and safe technique allowing for a dynamic and three-dimensional urethra assessment. Yet, because of its limited value in detecting posterior urethral strictures, the standard urethrography should remain the basic 'road-map' prior to surgery. It is an operator-dependent technique, which can provide detailed information on the length, location, and extent of spongiofibrosis without risks of exposure to ionizing radiation.

Sagittal septum duplication of bladder and duplication of posterior urethra combined with congenital megacolon: a case report and literature review.

BACKGROUND: Duplication of the bladder with duplication of the posterior urethra is a relatively rare congenital malformation. Cases of sagittal septum duplication of the bladder with duplication of the posterior urethra have rarely been reported. Furthermore, the combination thereof with congenital megacolon is rare. CASE PRESENTATION: A 21-year-old male was admitted to our hospital because of frequent urination for two months. He presented to another hospital first with frequent urination and underwent computed tomography (CT) and testicular biopsy. Anti-inflammatory therapy was administered by the doctor to the patient. For further diagnosis and treatment, the patient went to the outpatient department in our hospital on June 6, 2022. After admission, the patient underwent ultrasound, CT, MRI, cystoscopy, and other related examinations and tests. The examination results suggested that the patient had duplication of the bladder with duplication of the posterior urethra. In addition, the patient's mother reported that he had suffered from long-term constipation with abdominal distension before the age of 5 years. At the time, he was admitted to the local hospital and was diagnosed with congenital megacolon based on the relevant examinations. After the patient was diagnosed with duplication of bladder and urethra, the doctor recommended surgical treatment to the patient. However, he considered that he only had frequent urination symptoms, and chose conservative treatment rather than to undergo surgical treatment. Thus, the doctor prescribed anti-inflammatory treatment. Four months later, the patient reported that frequent urination symptoms persisted, and was also considering fertility-related problems. The outpatient follow-up will be continued. CONCLUSIONS: In this article, we summarize the imaging findings of duplication of the bladder with duplication of the posterior urethra and propose the advantages and disadvantages of each type of imaging examination. We also review the relevant literature on cases of bladders with duplication of the posterior urethra. The related differential diagnosis is summarized, and the significance of guiding clinical treatment and diagnosis is discussed.

[New Sk2 guideline idiopathic posterior urethritis : Discussion of the current guideline using a case study]. / Neue Sk2-Leitlinie Urethritis posterior : Diskussion der aktuellen neuen Leitlinie anhand eines Fallbeispiels.

Posterior urethritis is diagnosed in prepubertal or pubertal boys mainly with terminal asymptomatic haematuria or postmicturition blood spotting on the meatus or in the underwear. It presents with typical changes in the bulbar urethra (hyperaemia, oedema and denuded mucosa) without laboratory or radiological findings. The pathology is self-limiting with a very good prognosis. This condition is most likely caused by dysfunctional voiding and urotherapy with biofeedback therapy offers good treatment results. Although urethrocystoscopy is the only way to confirm the diagnosis, the patient should be prevented from having a (usually unnecessary) urethrocystoscopy and the relatives should be reassured.

Diagnosis of traumatic urethral stricture in a canine patient with contrast-enhanced voiding urosonography : A case report.

A 5-year-old intact male mixed-breed dog presented with a 3-day history of stranguria and dysuria. Results of physical examination, plain radiographs, and ultrasonography were consistent with a traumatic urethral stricture in the prescrotal urethra just under the previous trauma region, resulting in partial obstruction of urine outflow. Contrast-enhanced voiding urosonography (CE-VUS) was performed, and a urethral stricture was confirmed. The dog underwent surgery. A scrotal urethrostomy was performed. After 3 days of hospitalization, the dog was discharged from the Clinic. Based on an extensive literature review, this is the first report using CE-VUS to evaluate urethral pathology in a canine patient.

Evaluation of pelvic structural abnormalities in primiparous women with stress urinary incontinence.

INTRODUCTION AND HYPOTHESIS: The objective was to evaluate the morphological characteristics of pelvic floor structure specific to de novo stress urinary incontinence (SUI) in primiparous women using three-dimensional (3D) reconstruction fusion technology based on static MRI combined with dynamic MRI. METHODS: Eighty-one primiparous women after the first vaginal delivery were studied, 40 with SUI and 41 without SUI. 3D reconstruction models based on static MRI were used to describe the anatomical abnormalities of pelvic floor tissues. Dynamic MRI was used to describe segmental activities of the urethra and vagina. The relationship between the morphometry and postpartum SUI was evaluated by logistic regression analysis and receiver operator characteristic curve. RESULTS: The differences in the distance from the bladder neck to the pubic symphysis (BSD), the angle between the posterior wall of the urethra and the anterior wall of the vagina, the width of the distal region of the vagina, urethral length, urethral compression muscle volume (CUV), and pubovisceral muscle volume, puborectal muscle volume, were measured, and except for the extremity of the anterior urethral wall, the total displacements (TDs) of the other sites between the two groups were statistically significant (p < 0.05). Logistic regression analysis showed that the BSD decreased, the CUV decreased, the TDs of the first site and the eighth site increment correlated significantly with postpartum SUI occurrence (p < 0.05). CONCLUSIONS: 3D reconstruction fusion technology provides an important support for a precise assessment of the pelvic floor dysfunction. The BSD, CUV, and iliococcygeus muscle volume have certain values in predicting de novo SUI after first vaginal birth.

Transrectal ultrasound vector projectile imaging for time-resolved visualization of flow dynamics in the male urethra: A clinical pilot study.

BACKGROUND: Quantitative and comprehensive visualization of urinary flow dynamics in the urethra is crucial for investigating patient-specific mechanisms of lower urinary tract symptoms (LUTS). Although some methods can evaluate the global properties of the urethra, it is critical to assess the local information, such as the location of the responsible lesion and its interactions with urinary flow in relation to LUTS. This approach is vital for enhancing personalized and focal treatments. However, there is a lack of such diagnostic tools that can directly observe how the urethral shape and motion impact urinary flow in the urethra. PURPOSE: This study aimed to develop a novel transrectal ultrasound imaging modality based on the contrast-enhanced urodynamic vector projectile imaging (CE-UroVPI) framework and validate its clinical applicability for visualizing time-resolved flow dynamics in the urethra. METHODS: A new CE-UroVPI system was developed using a research-purpose ultrasound platform and a custom transrectal linear probe, and an imaging protocol for acquiring urodynamic echo data in male patients was designed. Thirty-four male patients with LUTS participated in this study. CE-UroVPI was performed to acquire ultrasound echo signals from the participant's urethra and urinary flow at various voiding phases (initiation, maintenance, and terminal). The ultrasound datasets were processed with custom software to visualize urinary flow dynamics and urethra tissue deformation. RESULTS: The transrectal CE-UroVPI system successfully visualized the time-resolved multidirectional urinary flow dynamics in the prostatic urethra during the initiation, maintenance, and terminal phases of voiding in 17 patients at a frame rate of 1250 fps. The maximum flow speed measured in this study was 2.5 m/s. In addition, when the urethra had an obstruction or an irregular partial deformation, the devised imaging modality visualized complex flow patterns, such as vortices and flow jets around the lesion. CONCLUSIONS: Our study findings demonstrate that the transrectal CE-UroVPI system developed in this study can effectively image fluid-structural interactions in the urethra. This new diagnostic technology has the potential to facilitate quantitative and precise assessments of urethral voiding functions and aid in the improvement of focal and effective treatments for patients with LUTS.

Indirect signs of infravesical obstruction on voiding cystourethrography improve post-neonatal posterior urethral valves detection rate.

OBJECTIVES: To identify the diagnostic performance of clinical and radiological signs (on voiding cystourethrography [VCUG]) to detect posterior urethral valves (PUV) in the post-neonatal period. MATERIALS AND METHODS: One hundred eighteen males (median age = 0.8 years, range = 1 month-14 years, 48 toilet-trained) undergoing VCUG in a 2-year period were prospectively enrolled. Direct (dilated posterior urethra) and indirect (hypertrophied bladder neck, musculus interuretericus hypertrophy, and trabeculated appearance of the bladder wall) PUV signs on VCUG were assessed. Uroflowmetry was defined pathological by patterns suggesting infravesical obstruction. RESULTS: Twenty-two patients with direct, 28 with indirect PUV signs on VCUG, and one with normal VCUG but persisting micturition symptoms with pathological uroflowmetry underwent urethrocystoscopy and in 43/51 a PUV diagnosis was made (n = 22, 51.2%, with direct PUV signs). In 8/28 patients with indirect signs, PUV were not confirmed. Among non-toilet-trained patients, none of the clinical signs/symptoms was associated with PUV while among toilet-trained patients only pathological uroflowmetry (odds ratio, OR = 4.0 [95% confidence interval:1.2-13.2; p = 0.02]) and pathological uroflowmetry with history of urinary tract infection (OR = infinity) were significantly associated with PUV. Significant associations with PUV of direct and indirect signs on VCUG were found both in toilet-trained and non-toilet trained patients. Direct PUV sign had 100% specificity and sensitivity while indirect PUV signs showed sensitivity = 58.1% and specificity = 89.3%. The absence of any radiological sign had a negative predictive value = 98.5%. CONCLUSION: Only half of patients with endoscopy-confirmed PUV presents with direct sign of PUV on VCUG. Accounting for indirect PUV signs on VCUG and pathological uroflowmetry (in toilet-trained children) could improve the PUV detection rate. CLINICAL RELEVANCE STATEMENT: Indirect radiological PUV signs should be valorized when interpreting VCUG to improve the PUV detection rate. The absence of any radiological PUV (direct and indirect) sign on VCUG excludes PUV with a very high negative predictive value. KEY POINTS: • Worldwide agreement is that a non-dilated urethra on voiding cystourethrography excludes obstruction. • Half of patients with posterior urethral valves have non-dilated urethra on voiding cystourethrography. • Accounting for indirect signs of posterior urethral valves on voiding cystourethrography improves the diagnostic performance.

Urethro-urethrostomy for urethral duplication (Type IIA1) in a 3-years-old boy: Surgical approach.

INTRODUCTION: To report a novel maneuver of end-to-side urethro-urethrostomy for managing Type IIA1 urethral duplication (UD). MATERIALS AND METHODS: A 3-years-old boy was referred to our institute for abnormal appearance of genitalia. Physical examination revealed an epispadiac meatus on the dorsum of the penile shaft, in addition to the orthotopic meatus at the tip of glans. He can void through both urethrae with continence (grade I). Voiding cystourethrography and the cystoscopy confirmed the Type IIA1 UD with two urethrae arising independently from the bladder neck. A novel maneuver of end-to-side urethro-urethrostomy transferring the dorsal urethra through the corpus cavernosa and anastomosing it to the posterior wall of the ventral urethra was successfully performed. RESULTS: The urethral catheter was removed 2 weeks postoperatively. Neither urethral stricture nor fistula was noticed. After 1 year of followed-up, the boy can void fluently with continence (grade I). The Qmax was 10.4 ml/s. CONCLUSION: Our maneuver of end-to-side urethro-urethrostomy for managing Type IIA1 UD was safe and effective, especially for the continent cases with the ectopic meatus on the penile shaft.

Objective documentation of hypospadias anatomy with three-dimensional scanning.

INTRODUCTION: The absence of a standardized classification of hypospadias hinders understanding of the anatomic differences among patients and the evaluation of outcomes following surgical repair. In working towards a standardized, objective method of recording patients' hypospadias anatomy, we describe our initial experience using a non-invasive three-dimensional scanner. MATERIAL AND METHODS: An Artec3D Space Spider scanner was used to obtain 3D scans in 29 patients undergoing hypospadias repair. Measurements of the urethral plate width, urethral plate length, glans width, penile shaft length, and penile shaft width were made by 2 pediatric urology attendings and 1 pediatric urology fellow. Measurements were compared and inter-rater reliability was calculated. RESULTS: A total of 435 measurements were made on 29 successfully generated 3D scans, ranging from distal to proximal hypospadias. The inter-rater reliability of measurements from the generated 3D models shown good inter-rater reliability of urethral plate width (ICC0.87 [95%CI:0.76,0.93]), penile shaft length (ICC0.87 [95%CI:0.70,0.94]) and glans width (ICC0.83 [95%CI:0.68,0.92]), excellent inter-rater reliability of urethral plate length (ICC0.96) and moderate inter-rater reliability of penile shaft width (ICC0.69 [95%CI:0.44,0.84]). DISCUSSION: There was a high degree of reliability of measurements made across multiple users. Calculation of the ratio of the urethral plate length/total penile shaft length objectively defined the initial position of the urethral meatus. When compared to the 3-dimensional volume of the glans, a more proximally positioned urethral meatus was associated with a lower glans volume. CONCLUSION: 3D scanning offers a rapid, reproducible, and non-invasive method of documenting hypospadias anatomy. The ability to evaluate three dimensional features (i.e. glans volume) offers an exciting opportunities for robust investigation of hypospadias outcomes and further understanding of the relationship between a patient's genotype and phenotype.

External validation and reliability assessment of posterior urethral morphology on initial voiding cystourethrogram as a predictor for infants with posterior urethral valves.

INTRODUCTION: The morphology of the bladder and posterior urethra on initial voiding cystourethrogram (VCUG) in posterior urethral valve (PUV) has been proposed as a meaningful early metric for short- and long-term kidney outcomes. Here, we seek to externally validate the proposed association and assess the reliability of PUV morphology characteristics. MATERIALS AND METHODS: We reviewed our institutional database for patients managed for PUV between 2000 and 2022 and included those treated with primary ablation with at least 1 year of follow-up for kidney function. Each VCUG was evaluated by three independent raters for the height-width ratio of the bladder (HW-B), height-width ratio of the posterior urethra (HW-PU), and posterior-anterior urethral ratio (PA-UR), and trabeculation (none, fine, or coarse). We assessed the reliability in these with intra-class coefficient and Fleiss kappa for continuous and categorical data, respectively. We performed univariate analysis with nadir creatinine and five-year follow-up glomerular filtration rate (GFR). RESULTS: In total, 98 patients met inclusion criteria. The median age at diagnosis and ablation was 10 and 21 days, respectively. Patients with nadir creatinine <0.8 mg/dL had higher follow-up GFR (101 vs. 20 ml/min/1.73 m2, p = 0.04), and lower risk of CKD (odds ratio 14.7, p = 0.002). The median value for HW-B was 1.4, median HW-PU was 2.1, and median PA-U was 4.7, There was significant inter-class agreement between all three measures of 0.80, 0.51, and 0.70 (p < 0.001). The inter-rater agreement for bladder trabeculation was fair (Fleiss K = 0.40, p < 0.001). There was no statistically significant correlation between HW-B, HW-PU, PU-A with nadir creatinine (p = 0.07, 0.33, 0.91) or 5-year GFR (0.27, 0.45, 0.62), respectively. DISCUSSION: There is significant interest in determining prognostic factors and metrics in PUV. The morphological characteristics on VCUG are reliable and is available information for all boys diagnosed with PUV, resulting in an attractive metric. While we do not demonstrate correlation with kidney outcomes, VCUG features warrant further attention as prognostic factors in PUV. CONCLUSIONS: PUV morphology on initial VCUG is a reliable metric of lower urinary tract deformity but is not associated with 5-year kidney outcomes.

Primary management of pelvic fracture urethral injury in a woman: challenges and outcome.

Literature on the management of pelvic fracture urethral injuries (PFUI) in women is scarce. We present a case of PFUI in a woman.A woman in her 50s presented with lower abdominal pain, bleeding per vaginum and inability to void following road traffic accident. Local examination showed mid-urethral transection injury and tear over the left anterolateral aspect of the vagina. Foley's catheter bulb and bony fragments of the fractured pelvis were palpable anteriorly. Imaging revealed bilateral superior and inferior rami fractures with pubic bone diastasis. She underwent external fixation of pelvic bones with primary repair of urethral and vaginal mucosal injury.Intraoperatively external pelvic fixator was applied, following which the bony fragments in the vagina were lifted up (due to the realignment of pelvic bones). Mid-urethral transection injury was repaired using end-to-end anastomotic urethroplasty. Per-urethral catheter and suprapubic catheter were placed. Periurethral tissue and vaginal layers were closed over the urethral repair. The postoperative course was uneventful.External pelvic fixator was removed after 6 weeks of surgery. Micturating cystogram showed no evidence of contrast extravasation. Follow-up at 3 months showed no urinary symptoms with a bell-shaped uroflowmetry curve.

An innovative method for occluding the urethral meatus and accessing urethra strictures in retrograde urethrography in males.

OBJECTIVES: To observe and evaluate the effectiveness and safety of using a sponge plug method to occlude the urethral meatus during retrograde urethrography (RUG) for accessing male urethral strictures. METHODS: 40 male patients with a mean age of 51.4 years and a history of urethral injury were primarily diagnosed with urethral stricture using a urethrocystoscope. RUG was performed using a ureteral catheter with a sponge plug inserted into the external meatus. Iodixanol, a contrast medium, was injected into the urethra or bladder for performing RUG and voiding cystourethrography (VCUG). The patients were positioned obliquely to obtain urethrograms. RESULTS: All X-ray radiologic procedures for performing urethrography were successful without any overflow of contrast liquid observed. In all cases, the sponge plugs became visible in the resulting images. The external meatuses were directly visualized in all cases on the obtained images, allowing identification of the number, location, and length of strictures as well as coexistent pathologies such as fistulas. In one case, the plug slipped off the meatus immediately after completing the procedure. The pain Visual Analogue Scale (VAS) was 0 to 2, mean 0.35. No instances of complication or adverse reactions was observed. CONCLUSIONS: The sponge plug effectively occludes the external urethral meatus for retrograde urethrography, enabling visualization of the actual caliber of the entire urethra, including the strictures and external meatus, by filling it with contrast liquid. This technique is safe and well-tolerated by patients.

Urethral identification using three-dimensional magnetic resonance imaging and interfraction urethral motion evaluation for prostate stereotactic body radiotherapy.

Prostatic urethra identification is crucial in prostate stereotactic body radiotherapy (SBRT) to reduce the risk of urinary toxicity. Although computed tomography (CT) with a catheter is commonly employed, it is invasive, and catheter placement may displace the urethral position, resulting in possible planning inaccuracies. However, magnetic resonance imaging (MRI) can overcome these weaknesses. Accurate urethral identification and minimal daily variation could ensure a highly accurate SBRT. In this study, we investigated the usefulness of a three-dimensional (3D) T2-weighted (T2W) sequence for urethral identification, and the interfractional motion of the prostatic urethra on CT with a catheter and MRI without a catheter for implementing noninvasive SBRT. Thirty-two patients were divided into three groups. The first group underwent MRI without a catheter to evaluate urethral identification by two-dimensional (2D)- and 3D-T2W sequences using mean slice-wise Hausdorff distance (MSHD) and Dice similarity coefficient (DSC) of the contouring by two operators and using visual assessment. The second group provided 3-day MRI data without a catheter using 3D-T2W, and the third provided 3-day CT data with a catheter to evaluate the interfractional motion using MSHD, DSC, and displacement distance (Dd). The MSHD and DSC for the interoperator variability in urethral identification and visual assessment were superior in 3D-T2W than in 2D-T2W. Regarding interfractional motion, the Dd value for prostatic urethra was smaller in MRI than in CT. These findings indicate that the 3D-T2W yielded adequate prostatic urethral identification, and catheter-free MRI resulted in less interfractional motion, suggesting that 3D-T2W MRI without a catheter is a feasible noninvasive approach to performing prostate SBRT.