Optimizing anterior urethral stricture assessment: leveraging AI-assisted three-dimensional sonourethrography in clinical practice.

PURPOSE: This investigation sought to validate the clinical precision and practical applicability of AI-enhanced three-dimensional sonographic imaging for the identification of anterior urethral stricture. METHODS: The study enrolled 63 male patients with diagnosed anterior urethral strictures alongside 10 healthy volunteers to serve as controls. The imaging protocol utilized a high-frequency 3D ultrasound system combined with a linear stepper motor, which enabled precise and rapid image acquisition. For image analysis, an advanced AI-based segmentation process using a modified U-net algorithm was implemented to perform real-time, high-resolution segmentation and three-dimensional reconstruction of the urethra. A comparative analysis was performed against the surgically measured stricture lengths. Spearman's correlation analysis was executed to assess the findings. RESULTS: The AI model completed the entire processing sequence, encompassing recognition, segmentation, and reconstruction, within approximately 5 min. The mean intraoperative length of urethral stricture was determined to be 14.4 ± 8.4 mm. Notably, the mean lengths of the urethral strictures reconstructed by manual and AI models were 13.1 ± 7.5 mm and 13.4 ± 7.2 mm, respectively. Interestingly, no statistically significant disparity in urethral stricture length between manually reconstructed and AI-reconstructed images was observed. Spearman's correlation analysis underscored a more robust association of AI-reconstructed images with intraoperative urethral stricture length than manually reconstructed 3D images (0.870 vs. 0.820). Furthermore, AI-reconstructed images provided detailed views of the corpus spongiosum fibrosis from multiple perspectives. CONCLUSIONS: The research heralds the inception of an innovative, efficient AI-driven sonographic approach for three-dimensional visualization of urethral strictures, substantiating its viability and superiority in clinical application.

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.

Application progress of imaging examination in the diagnosis of urethral stricture / 现代泌尿外科杂志

Urethra stricture is one of the most common diseases of the urinary system. Accurate imaging diagnosis is key to the selection of surgical approach. At present, X-ray urethral imaging can show the form of urethra cavity, but not the tissues around the urethra. Sonourethrography (SUG) can dynamically identify the urethral cavity and the surrounding tissues without radiation exposure. Multi-layer spiral CT urethrography (CTU) has advantages of no need to adjust the position, quick scanning and reconstruction of the three-dimensional image, which can accurately show the location, length and degree of urethral stricture, and the spatial relationship with the surrounding tissues. Magnetic resonance urethrography (MRU) can provide useful information of the urethral stricture and soft tissues around the urethra, especially in urethral strictures caused by pelvic fractures and complex urethral stenosis. The choice of imaging method should be based on the etiology, anatomy, types of urethral injury and the general situation of patients. Appropriate imaging method can improve the diagnostic accuracy.

Extent of spongiofibrosis and length of strictures: Findings at sonourethrography and urethroplasty.

INTRODUCTION: The purpose of this study was to diagnose urethral stricture and to determine the extent of spongiofibrosis as well as the length of stricture using sonourethrography and compare it with intraoperative findings. PATIENTS AND METHODS: It was a cross sectional observational study from September 2017-August 2018. All patients who presented with urethral stricture, scheduled for urethroplasty, and consented to the study were enrolled. The extent of spongiofibrosis and length of strictures were determined at sonourethrography and subsequently at urethroplasty. Sensitivity, specificity, positive predictive value and negative predictive values of sonourethrography in the determination of length of stricture was done. Spearman correlation coefficient(r) was used to describe the association between the extent of spongiofibrosis found at sonourethrography and at urethroplasty. RESULTS: A total of 84 patients were evaluated during the study period. The median age at presentation was 45years. 81% of the patients had moderate spongiofibrosis on sonourethrography. There was a significant correlation of 71.4% between the extent of spongiofibrosis on sonourethrography and at urethroplasty. In evaluation for the length of strictures, sonourethrography had a sensitivity of 84.6% specificity of 82.7%, PPV of 68.7% and NPV 92.3%. CONCLUSION: Sonourethrography is a valuable tool in the evaluation of urethral strictures. Its radiation free readily available even in resource-poor settings and gives a good evaluation of extent of spongiofibrosis as well as the length of strictures. It's use in the preoperative evaluation of strictures may improve the outcome of the management of strictures.

Morphological and clinical evaluation of prostatic urethra using modified sonourethrography with retrograde jelly injection.

OBJECTIVE: Using modified sonourethrography (mSUG) with retrograde jelly injection to precisely measure the morphological characteristics of the prostatic urethra, we assessed prostatic urethral morphology associated with clinical parameters of benign prostatic hyperplasia (BPH). METHODS: BPH patients (n = 43) and control patients with localized prostate cancer (PC; n = 57) were imaged by mSUG before surgery. Using the seminal colliculus as a landmark, prostatic urethral angulation (PUA), sagittal urethral diameter, and anterior or posterior prostatic urethral length were measured. The International Prostatic Symptoms Score (IPSS) was also evaluated in all patients. The Bladder Outlet Obstruction Index (BOOI) was measured in BPH patients that could void in a pressure-flow study. Parameters were compared between BPH and PC patients, and correlations among morphological and clinical parameters were evaluated. RESULTS: Prostatic urethras were clearly observed in all patients by mSUG. PUA, sagittal urethral diameter, and posterior urethral length were all greater in BPH than PC patients (P < .05). Among all parameters examined, PUA had the strongest correlation with IPSS (r = 0.56). Longitudinal urethral diameter showed the strongest correlation with BOOI, whereas PUA was not correlated with BOOI. CONCLUSIONS: Prostatic urethral morphology can be imaged precisely by mSUG. Morphometric measurements showed that increased PUA was strongly correlated with problematic urinary symptoms, and a flattened shape of the posterior urethra, such as extension of the sagittal urethral diameter, was correlated with urinary tract obstruction by BPH.

Optimisation of sonourethrography: the clamp method.

PURPOSE: To describe the clamp method for performing retrograde sonourethrography (RSUG) and contrast-enhanced voiding sonourethrography (CE-VSUG) via the transperineal approach in male adults. MATERIALS AND METHODS: Prospective study of 113 males (14-86 years) with urethral strictures confirmed by urethrography who received sonourethrography via the clamp method between 2011 and 2015. The characteristic parameters of the quantitative variables were calculated and a comparative analysis of the qualitative variables was conducted using the McNemar test. RESULTS: RSUG was performed successfully in all the cases (n = 113) and detected 49 cases with anterior urethral strictures; the strictures in the proximal bulbar cone in five of them (10.2%) were not visualised on retrograde urethrography (RUG) (p < 0.05). CE-VSUG was performed successfully in 97 cases and observed posterior urethral strictures in 82; the bladder neck strictures in 6 of them (7.3%) were not observed on voiding cystourethrography (VCUG) (p < 0.05). Retrograde bladder filling was achieved in approximately 6 min. CONCLUSION: The clamp method enables RSUG and CE-VSUG to be performed simply, effectively and painlessly by a single operator. It also allows the evaluation of cases with urethromeatal alterations (stricture, hypospadias and meatotomy). KEY POINTS: • The clamp method enables RSUG to be performed simply and painlessly. • The clamp method requires only one operator and allows assessing urethromeatal alterations. • RSUG shows greater capacity for detecting anterior urethral strictures than RUG. • The clamp method achieves retrograde bladder filling in approximately 6 min. • CE-VSUG shows greater capacity for detecting strictures than VCUG.

Comparison of Diagnostic Value of Sonourethrography with Retrograde Urethrography in Diagnosis of Anterior Urethral Stricture.

BACKGROUND: In spite of the advanced imaging methods, MRI and CT-Scan, the role of ultrasonography is still unique in some fields of genitourinary tract diseases. AIM: This study was aimed at assessing this role in the evaluation of male urinary stricture, and comparison with standard retrograde urethrography (SUG). METHODS: This was a cross-sectional study. The patients include those who were suspected of anterior urethral stricture and were introduced assessed with imaging techniques (RUG). The patient underwent ultrasonography too. The results of both methods were compared. RUG was considered as the gold standard for this comparison. RESULT: Ninety-seven patients were studied. The mean age was 46.9 ± 11.7 years (range 21-88 years), in RUG, 22 patients (22.8%) and SUG 23 patients (23.7%) had a stricture, 3 cases with a stricture in RUG had not evidenced of stenosis in SUG. The mean length of urethral stricture in RUG was 12.9 ± 8.1 mm and in SUG was 8.1 ± 7.3 mm. The estimated length in RUG way was significantly higher than SUG way (P=0.025). The sensitivity and specificity in using of SUG were 86.6% and 94.6%, respectively. CONCLUSION: The result of this study showed stricture length measured by ultrasound is shorter than the length measured by RUG and the sensitivity and specificity in using of SUG was 86.6% and 94.6% respectively that due to the advantages it is an acceptable way.

Comparison of sonoelastography with sonourethrography and retrograde urethrography in the evaluation of male anterior urethral strictures.

OBJECTIVE: Retrograde urethrography (RUG) is the most common and preferred imaging modality for imaging of the anterior urethral strictures despite its well-known limitations and disadvantages. Sonourethrography (SUG) was introduced in 1988 to overcome the limitations of RUG and to provide more accurate results. As proper selection of imaging modality is very important for planning the treatment, various advances in this area are required. One of the major factors for recurrence of stricture disease is spongiofibrosis. Sonoelastography (SE) is a newer technique, tried in various other pathologies. In this study, we have used this technique for the first time to assess its efficacy in the evaluation of anterior urethral stricture disease by comparison with RUG and SUG. MATERIAL AND METHODS: Between August 2014 and May 2015, 77 patients with clinical features of anterior urethral stricture disease were included in the study and evaluated by RUG followed by SUG and SE for stricture location, length, depth of spongiofibrosis and periurethral pathologies. The results were then correlated with operative and histopathological findings. RESULTS: Overall diagnostic accuracy of SE, SUG, and RGU for the estimation of stricture location, and length were estimated 92.68% vs. 91.54%, 79% vs. 78.87% and 80.48% vs. 43.66%, respectively, while for depth of spongiofibrosis SE, and SUG had accuracy rates of 87.3%, 48%, respectively. The mean length measured on SE was nearest to the mean intra-operative stricture length (21.34+11.8 mm). SE findings significantly correlated with the colour of bladder mucosa on cystoscopic examination (p=0.003) whereas the association was non-significant (p=0.127) for difficulty in incision. While a nonsignificant correlation existed between SUG findings related both to the colour of the bladder mucosa and difficulty in incision on cystoscopy, SE findings had a significant association (p<0.001) with histopathology findings for severe degree of fibrosis. CONCLUSION: Sonoelastography estimates stricture site and length better in comparison with RUG and SUG. It estimates degree of spongiofibrosis which serves as an important prognostic factor for stricture recurrence more accurately than SUG.

Modified sonourethrography assists urethral catheterization.

Sonourethrography (SUG) is an infrequently used modality to observe the male urethra. We modified SUG to examine the reasons for difficulty in urethral catheterization and to determine a safe approach to resolve these problems. Following retrograde urethral jelly injection, modified SUG (mSUG) was performed in male patients with difficulty in urethral catheterization. mSUG was performed using transcutaneous ultrasonography in patients for whom the catheter became lodged in the penile urethra. In other patients, mSUG was performed using transrectal ultrasonography. We divided the causes of difficult indwelling urethral catheterization into physiological and pathological conditions. With regard to physiological conditions, the urethral catheter became stuck in the bulbous portion, membranous urethra, and prostatic urethra. mSUG distinguished the problematic part of the urethra in real time, and it assisted in overcoming the problem. With regard to pathological conditions, urethral stricture after trauma or surgery was clearly demonstrated in the penile and prostatic portions of the urethra. As with physiological conditions, mSUG images assisted in navigating the catheter through the problematic pathological areas or demonstrated the need to abandon the catheterization. mSUG can visualize the male urethra clearly during urethral catheterization and provide real-time assistance with the procedure.

Usefulness of sonourethrography for penile abscess as a result of xanthogranulomatous granuloma in the corpus cavernosum of an adult: A case report.

A 75-year-old man presented with a 4-month history of a swollen and painful penis. Computed tomography showed a round-shaped mass measuring 3 × 2 cm in the corpus cavernosum. Percutaneous drainage of the penile mass was carried out and a course of antibiotics was prescribed. Viral, fungal and selective bacterial cultures were negative. Total penectomy and urethroperineal fistula formation were carried out because of penile pain. Histopathological diagnosis was xanthogranulomatous granuloma of the corpus cavernosum. Before surgery, sonourethrography was carried out under general anesthesia. Sonourethrography is an infrequently used modality to observe the male urethra under urinary micturition or injection of saline. We previously reported modified sonourethrography with retrograde jelly injection. In the present case, sonourethrography successfully showed the damaged and deformed urethra including the abscess cavity and fistula. Although xanthogranulomatous granuloma is rare, the findings reported here showed the usefulness of sonourethrography for morphological evaluation of the male urethra.

Clinical value of sonourethrography in the diagnosis of dysuria after bipolar transurethral plasmakinetic prostatectomy / 中华泌尿外科杂志

Objective To evaluate the value of sonourethrography in the diagnosis of dysuria after bipolar transurethral plasmakinetic prostatectomy. Methods Sixty male patients with dysuria after bipolar transurethral plasmakinetic prostatectomy underwent sonourethrography and re-operation.The clinical data of these patients were reviewed. Results The sonourethrographic findings were similar with the operative findings in 57 cases.In the 60 cases,there were 11 cases with bladder neck closure,10 cases with bladder neck stricture,30 cases with urethral stricture (16 located at membranous urethra,12 located at pars cavernosa urethra and 2 in external orifice of urethra),5 cases with prostate remnant,1 case with calculi in prostatic urethra,2 cases with dysfunction of detrusor of bladder and 1 case with flap of internal urethral orifice,Conclusions Sonourethrography could be a reliable diagnostic method for dysuria after bipolar transurethral plasmakinetic prostatectomy.It may be helpful for clinical treatment.