Contrast-enhanced Voiding Urosonography for Vesicoureteral Reflux Diagnosis in Children

Diagnosis of Pediatric Appendicovesical Fistula by Contrast-enhanced Ultrasound: A Case Report

Appendicovesical fistula is a rare complication associated with appendicitis, Crohn's disease, or appendiceal tumors, posing significant diagnostic challenges. We reported a pediatric case of appendicovesical fistula that remained undiagnosed by non-contrast computed tomography, fluoroscopic voiding cystourethrography (VCUG). Although identified during cystoscopy, its connection to the fistula site could not be determined. However, the transvesical contrast-enhanced ultrasound clearly demonstrated the presence of fistula. Subsequently, laparoscopic appendectomy and bladder repair were performed successfully, leading to complete recovery in the patient. To our knowledge, this is the first reported diagnosis of appendicovesical fistula in children using contrast-enhanced ultrasound.

ACR Appropriateness Criteria® Urinary Tract Infection-Child: 2023 Update

Urinary tract infection (UTI) is a frequent infection in childhood. The diagnosis is usually made by history and physical examination and confirmed by urine analysis. Cystitis is infection or inflammation confined to the bladder, whereas pyelonephritis is infection or inflammation of kidneys. Pyelonephritis can cause renal scarring, which is the most severe long-term sequela of UTI and can lead to accelerated nephrosclerosis, leading to hypertension and chronic renal failure. The role of imaging is to guide treatment by identifying patients who are at high risk to develop recurrent UTIs or renal scarring. This document provides initial imaging guidelines for children presenting with first febrile UTI with appropriate response to medical management, atypical or recurrent febrile UTI, and follow-up imaging for children with established vesicoureteral reflux. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

The Intrarenal Reflux Diagnosed by Contrast-Enhanced Voiding Urosonography (ceVUS): A Reason for the Reclassification of Vesicoureteral Reflux and New Therapeutic Approach?

Vesicoureteral reflux (VUR) is defined as the urine backflow from the urinary bladder to the pyelo-caliceal system. In contrast, intrarenal reflux (IRR) is the backflow of urine from the renal calyces into the tubulointerstitial space. VURs, particularly those associated with IRR can result in reflux nephropathy when accompanied by urinary tract infection (UTI). The prevalence of IRR in patients with diagnosed VUR is 1-11% when using voiding cystourethrography (VCUG), while 11.9-61% when applying the contrast-enhanced voiding urosonography (ceVUS). The presence of IRR diagnosed by VCUG often correlates with parenchymal scars, when diagnosed by a 99mTc dimercaptosuccinic acid scan (DMSA scan), mostly in kidneys with high-grade VURs, and when diagnosed by ceVUS, it correlates with the wide spectrum of parenchymal changes on DMSA scan. The study performed by both ceVUS and DMSA scans showed IRRs associated with non-dilated VURs in 21% of all detected VURs. A significant difference regarding the existence of parenchymal damage was disclosed between the IRR-associated and IRR-non-associated VURs. A higher portion of parenchymal changes existed in the IRR-associated VURs, regardless of the VUR grade. That means that kidneys with IRR-associated VURs represent the high-risk group of VURs, which must be considered in the future classification of VURs. When using ceVUS, 62% of places where IRR was found were still unaffected by parenchymal changes. That was the basis for our recommendation of preventive use of long-term antibiotic prophylaxis until the IRR disappearance, regardless of the VUR grade. We propose a new classification of VURs using the ceVUS method, in which each VUR grade is subdivided based on the presence of an IRR.

Novel use of contrast enhanced ultrasonography with urodynamics in children: A comparison study to fluoroscopy

INTRODUCTION

Video urodynamics (UDS) has classically been performed using fluoroscopy (fluoro). Contrast enhanced voiding ultrasonography (ceVUS) has rarely been reported for use with UDS. This is the first study to compare the imaging characteristics of ceVUS versus fluoro UDS.

METHODS

Children were enrolled for ceVUS UDS who previously underwent fluoro UDS. Demographics, imaging data for ceVUS and fluoro UDS, time between studies, and clinical data between studies were recorded. Changes in clinical status included implantation/cessation of catheterization or anticholinergic medications, leakage between, urinary tract infections, hydronephrosis and neurologic changes. Comparison testing was performed using McNemar's Chi-Squared and Wilcoxon matched-pairs signed rank test.

RESULTS

Seventy-five children were recruited. Median time between studies was 1.3 years (IQR 0.9-2.9). There were no differences for bladder shape (p = 0.59), vesicoureteral reflux (p = 0.10), bladder neck (p = 0.59) or urethra (p = 1.0) between studies. In 5 cases, the bladder neck could not be visualized adequately due to layering of the microbubble contrast against urine. Benefits to ceVUS included ability to visualize the exact moment the bladder neck opened. Following exclusion of patients with clinical changes that might affect imaging findings, an analysis of 28 patients demonstrated no differences between the two studies.

CONCLUSIONS

CeVUS can be used adequately in conjunction with UDS. Limitations to ceVUS include more granular imaging for bladder shape versus fluoro and inability to visualize bladder neck if residual urine is in the bladder, mitigated by bladder emptying. Benefits include ability to visualize the dynamic activity of the bladder neck due to constant imaging with ceVUS.

Vesicoureteral reflux by contrast ultrasound, comparison with voiding and retrograde urethrocystography: A prospective accuracy study

INTRODUCTION

Diagnosis of vesicoureteral reflux (VUR) plays an important role in the management and follow-up of children presenting with urinary tract infection. This study compared voiding uronosography (VUS) as a diagnostic method for the diagnosis of VUR with the "gold standard", voiding or micturating cystourethrography (MCU). The objective of the study is not only to compare the effectiveness of both methods, but also to assess the feasibility of implementing VUS technically and economically in a large tertiary radiology center in South America.

MATERIALS AND METHOD

This was a prospective accuracy study that include 41 patients (a total of 85 ureteral units) aged between 1 month and 16 years. VUS was performed in an alternative form as regular MCU, by injecting microbubble contrast solution (SonoVue©) into the bladder through an intermittent catheter and evaluating the presence of reflux with ultrasound. MCU was always performed immediately after VUS. One pediatric radiologist evaluated all VUS exams, while a second independent pediatric radiologist evaluated all MCU exams, with both blinded to each other's assessments.

RESULTS

Comparing VUS with MCU in the diagnosis of VUR, we observed a sensitivity of 92.3 % (95 % CI 74.9-99.1 %), specificity of 98.3 % (95 % CI 90.9-100 %), positive predictive value of 96.0 % (95 % CI 79.6-99.9 %), negative predictive value of 96.7 % (95 % CI 88.5-99.6 %) and a Kappa of 0.916 (0.822-1.000). When comparing the VUR grading between VUS and MCU the agreement between the two methods was high with a Kendall's Tau-b > 0.9. VUS failed to diagnose two grade 1 VUR reflux cases in teenagers while diagnosing one grade 4 VUR in a very dilated kidney-ureter unit, which was missed on MCU. VUS and MCU had similar costs when considering the price of the ultrasound contrast agent.

DISCUSSION

VUS is a reliable alternative method to MCU for the diagnosis of VUR with the advantages of not exposing the child to ionizing radiation and potentially being more accessible due to the greater availability of ultrasound equipment. Limitations to this study include the usage of a single ultrasound equipment, which limits its generalizability and not evaluating the interobserver variability.

CONCLUSION

Consideration should be given to implementing VUS for the diagnosis of VUR, particularly in centers without fluoroscopy equipment available, since the exam's performance and cost are comparable to those of the MCU.

Parental perception of contrast enhanced voiding ultrasonography urodynamics vs fluoroscopic urodynamics

INTRODUCTION/OBJECTIVES

Contrast enhanced voiding ultrasonography (ceVUS) has not been widely reported to be used during video urodynamics (UDS). We previously reported on the feasibility of this. In this study, we aimed to understand how parents perceived their child's experience of undergoing ceVUS during UDS compared to fluoroscopic (fluoro) UDS.

METHODS

Children who underwent both fluoro UDS and ceVUS UDS were recruited. Parents were asked to complete a questionnaire to evaluate their experience with both studies. Demographics including gender, age at study, and diagnosis were collected to account for differences in perception. Statistical analysis was performed.

RESULTS

53 patients were included: 31 girls, 22 boys. Diagnoses included myelomeningocele (67.9%), low/tethered cord (13.2%), closed spinal dysraphism (9.4%), posterior urethral valve (1.9%), cloacal anomaly (1.9%), caudal regression (1.9%), myeloschisis (1.9%), and cerebral palsy (1.9%). There was no statistical difference in mean age at fluoro UDS and ceVUS UDS (77.3 months vs 99.7 months respectively, p = 0.09). All 53 parents (100%) were satisfied/very satisfied with their ceVUS experience; 48 parents (90.6%) preferred ceVUS, 3 parents (5.7%) preferred fluoro UDS, and 2 (3.8%) were neutral. On average, parents perceived ceVUS to be more comfortable (72.7%) and produce better results (67.4%) than fluoro UDS. The majority felt that both studies allowed the same contact with their child (52.3%) and took the same amount of time (50.0%). However 29.5% felt ceVUS was faster and 34.1% felt ceVUS allowed more contact with their child (Fig. 1). 26 parents (49.1%) specifically noted no radiation as the reason why they preferred ceVUS over fluoro. The average age at ceVUS UDS was younger in those who preferred ceVUS UDS compared to those who preferred fluoro UDS (94.6 months vs 180.0 months, p = 0.03). The average age at fluoro UDS was younger in those who preferred ceVUS UDS vs fluoro UDS (73.1 months vs 144 months, p = 0.03). Gender's influence on preference approached significance (p = 0.07); all 3 parents who preferred fluoro UDS had male children.

CONCLUSIONS

The majority of parents preferred ceVUS over fluoro UDS. ceVUS was perceived to be more comfortable and provide better results. Many parents highlighted no radiation and no fluoroscopic machinery as factors in preference of ceVUS over fluoro. The parents who preferred ceVUS UDS had children who had both studies done at an earlier age compared to the parents who preferred fluoro UDS.

Application of contrast-enhanced ultrasound in the surgical treatment of vesicoureteral reflux in children

BACKGROUND

To determine the utility of contrast-enhanced voiding urography (CeVUS) in the treatment of vesicoureteral reflux (VUR) through ureterovesical reimplantation in children.

METHODS

A total of 159 children with recurrent urinary tract infections were selected for CeVUS and voiding cystourethrography (VCUG) from December 2018 to December 2020, among whom 78 patients were eventually diagnosed with VUR. Overall, 60 pyelo-ureteric units (PUUs) were operated according to surgical indications. Accordingly, we determined the general clinical characteristics of all children, obtained two-dimensional ultrasound images, assessed the reflux status of children using the contrast-enhanced technique, and compared the obtained results via CeVUS and VCUG. Both imaging modalities were reperformed at 6, 12, and 18 months after surgery to evaluate postoperative outcomes. In particular, we assessed the consistency of the evaluation and calculated the diagnostic efficacy of CeVUS for different levels of reflux at different time points.

RESULTS

CeVUS showed considerable efficacy in the diagnosis of children with VUR. Notably, the diagnostic results of both CeVUS and VCUG achieved high agreement, with a kappa value of 0.966 (P < 0.001). The results of our follow-up at different stages and evaluation of postoperative efficacy revealed that CeVUS possessed substantial diagnostic efficacy and good consistency with VCUG.

CONCLUSION

CeVUS is an accurate and safe examination, with considerable clinical significance for diagnosing VUR in children, determining the treatment approach, conducting follow-up during treatment, and evaluating subsequent treatment outcomes.

A narrative review on the applications of intracavitary contrast-enhanced ultrasonography in pediatric lower genitourinary anomalies

Purpose

We mainly aimed to perform a narrative review of clinical applications of the three intracavitary contrast-enhanced ultrasonography (CEUS) including contrast-enhanced voiding urosonography (ceVUS), contrast-enhanced retrograde urethrosonography (ceRUG), and contrast-enhanced genitosonography (ceGS) in pediatric lower genitourinary anomalies.

Method

A literature search in the PubMed and Web of Science databases was conducted up to 1 July 2022 on all studies published in English using the search terms "contrast-enhanced voiding urosonography", "contrast-enhanced retrograde urethrosonography", and "contrast-enhanced genitosonography". Trials were limited to pediatric subjects (ages ≤18 years) with no time restrictions. The inclusion criteria were studies on ceVUS, ceRUG, and ceGS to evaluate pediatric lower genitourinary anomalies. Two independent authors summarized the included articles.

Results

Finally, a total of 48 original articles and 6 case reports or case series were included, of which 50 (93%) were only relevant to ceVUS, 3 (5%) articles involved ceGS, while only one (2%) article involved ceRUG, and 87% of the applications of ceVUS were focused on vesicoureteral reflux (VUR). We also searched 24 related reviews, of which 20 involved ceVUS in diagnosing VUR and 4 involved ceRUG and ceGS for other lower genitourinary anomalies.

Conclusion

Intracavitary CEUS including ceVUS, ceRUG, and ceGS in pediatrics has many advantages over other radiological examinations in diagnosing lower genitourinary anomalies. Although ceVUS is widely used in detecting VUR, ceRUG and ceGS have also become promising techniques for evaluating the urethral pathologies and urogenital sinus.

Contrast-enhanced voiding urosonography (CEVUS) as a safe alternate means of assessing vesicoureteral reflux in pediatric kidney transplant patients

BACKGROUND

Although voiding cystourethrogram (VCUG) is currently the gold standard in VUR evaluation, there is ionizing radiation exposure. Contrast-enhanced voiding urosonography (CEVUS) uses ultrasound contrast agents to visualize the urinary tract and has been reported to be safe and effective in VUR evaluation in children. CEVUS application has yet to be specifically described in VUR evaluation in the pediatric kidney transplant population. The purpose of this study was to report the use of CEVUS and VCUG in evaluating and managing VUR in pediatric renal transplant patients.

METHODS

Retrospective review was conducted for pediatric kidney transplant patients (18 years and younger) who underwent VCUG or CEVUS to assess for transplant VUR from July 2019 through June 2021. Demographic information, reason for VUR evaluation, fluoroscopy time, and postimaging complications were evaluated. Costs of imaging modalities were also considered.

RESULTS

Eight patients were evaluated for transplant VUR during the study period. Of the 3 patients who underwent VCUG, all 3 had VUR (median grade 3). Median fluoroscopy time was 18 s and dose-area product was 18.7 uGy*m² . Of the 5 patients who underwent CEVUS, 4 had VUR (median grade 4). There were no complications for either modality. Based on clinical and radiographic findings, patients were recommended no intervention, behavioral modification, or ureteral reimplantation. The total cost of CEVUS was $800 less than that of VCUG.

CONCLUSION

CEVUS can provide an alternate means of safely evaluating VUR in kidney transplant patients with similar outcomes, potentially lower costs, and no exposure to ionizing radiation.

Prevalence of intrarenal reflux in pediatric patients on contrast-enhanced voiding urosonography

BACKGROUND

Intrarenal reflux may be seen with vesicoureteral reflux (VUR) when contrast from the pelvocalyceal system extends into tubules in the parenchyma. Because intrarenal reflux has been associated with scarring, detecting intrarenal reflux may influence management to avoid renal damage.

OBJECTIVE

Our objective was to evaluate the prevalence of intrarenal reflux identified on contrast-enhanced voiding urosonography (ceVUS) and its association with sex, age, grade of VUR, location in kidney and stage of bladder filling or voiding.

MATERIALS AND METHODS

CeVUS studies performed from August 2019 through July 2020 with VUR were retrospectively reviewed by two pediatric radiologists. They independently graded VUR and assessed for intrarenal reflux, noting its location and stage of bladder filling or voiding during which it occurred. The presence and location of scarring was also recorded.

RESULTS

One hundred and six ceVUS exams were reviewed with 211 kidneys evaluated (one solitary kidney). Patients were ages 2 weeks to 12 years (mean: 1.8 years) with 71 females (67%) and 35 males (33%). Grades 2 to 5 VUR were detected in 165 kidneys with intrarenal reflux seen in 42 (25.4%). Intrarenal reflux was present in 1 of 40 kidneys (2.5%) with grade 2, 10 of 67 (14.9%) with grade 3, 25 of 47 (53.2%) with grade 4 and 6 of 11 (54.5%) with grade 5 VUR. Intrarenal reflux occurred during voiding in 31 of 42 kidneys (73.8%) and was seen most often in the lower pole (71.4%) with significant association between intrarenal reflux and interpolar renal scarring (odds ration [OR] 3.92; 95% confidence interval [CI] 1.49, 10.32; P-value 0.01).

CONCLUSION

Intrarenal reflux was often seen on ceVUS, with the highest frequency occurring in young patients with grades 4 and 5 VUR and during voiding. Radiologists should have a high index of suspicion for intrarenal reflux on ceVUS, especially in young children with high-grade VUR.

Artifacts and Technical Considerations at Contrast-enhanced US

Contrast-enhanced US (CEUS), similar to other radiologic modalities, requires specific technical considerations and is subject to image artifacts. These artifacts may affect examination quality, negatively impact diagnostic accuracy, and decrease user comfort when using this emerging technique. Some artifacts are related to commonly known gray-scale US artifacts that can also appear on the contrast-only image (tissue-subtracted image obtained with the linear responses from background tissues nulled). These may include acoustic shadowing and enhancement; reverberation, refraction, and reflection; and poor penetration. Other artifacts are exclusive to CEUS owing to the techniques used for contrast mode image generation and the unique properties of the microbubbles that constitute ultrasound-specific contrast agents (UCAs). UCA-related artifacts may appear on the contrast-only image, the gray-scale image, or various Doppler mode images. Artifacts related to CEUS may include nonlinear artifacts and unintentional microbubble destruction resulting in pseudowashout. The microbubbles themselves may result in specific artifacts such as pseudoenhancement, signal saturation, and attenuation and shadowing and can confound the use of color and spectral Doppler US. Identifying and understanding these artifacts and knowing how to mitigate them may improve the quality of the imaging study, increase user confidence, and improve patient care. The authors review the principles of UCAs and the sound-microbubble interaction, as well as the technical aspects of image generation. Technical considerations, including patient positioning, depth, acoustic window, and contrast agent dose, also are discussed. Specific artifacts are described, with tips on how to identify and, if necessary, apply corrective measures, with the goal of improving examination quality. ^© RSNA, 2022 Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Fluorescence-Guided Surgery and Novel Innovative Technologies for Improved Visualization in Pediatric Urology

Fluorescence-guided surgery (FGS), three-dimensional (3D) imaging technologies, and other innovative devices are rapidly revolutionizing the field of urology, providing surgeons with powerful tools for a more complete understanding of patient-specific anatomy. Today, several new intraoperative imaging technologies and cutting-edge devices are available in adult urology to assist surgeons in delivering personalized interventions. Their applications are also gradually growing in general pediatric surgery, where the detailed visualization of normal and pathological structures has the potential to significantly minimize perioperative complications and improve surgical outcomes. In the field of pediatric urology, FGS, 3D reconstructions and printing technologies, augmented reality (AR) devices, contrast-enhanced ultrasound (CEUS), and intraoperative magnetic resonance imaging (iMRI) have been increasingly adopted for a more realistic understanding of the normal and abnormal anatomy, providing a valuable insight to deliver customized treatments in real time. This narrative review aims to illustrate the main applications of these new technologies and imaging devices in the clinical setting of pediatric urology by selecting, with a strict methodology, the most promising articles published in the international scientific literature on this topic. The purpose is to favor early adoption and stimulate more research on this topic for the benefit of children.

Tuberculosis conundrum - current and future scenarios: A proposed comprehensive approach combining laboratory, imaging, and computing advances

Tuberculosis (TB) remains a global threat, with the rise of multiple and extensively drug resistant TB posing additional challenges. The International health community has set various 5-yearly targets for TB elimination: mathematical modelling suggests that a 2050 target is feasible with a strategy combining better diagnostics, drugs, and vaccines to detect and treat both latent and active infection. The availability of rapid and highly sensitive diagnostic tools (Gene-Xpert, TB-Quick) will vastly facilitate population-level identification of TB (including rifampicin resistance and through it, multi-drug-resistant TB). Basic-research advances have illuminated molecular mechanisms in TB, including the protective role of Vitamin D. Also, Mycobacterium tuberculosis impairs the host immune response through epigenetic mechanisms (histone-binding modulation). Imaging will continue to be key, both for initial diagnosis and follow-up. We discuss advances in multiple imaging modalities to evaluate TB tissue changes, such as molecular imaging techniques (including pathogen-specific positron emission tomography imaging agents), non-invasive temporal monitoring, and computing enhancements to improve data acquisition and reduce scan times. Big data analysis and Artificial Intelligence (AI) algorithms, notably in the AI sub-field called “Deep Learning”, can potentially increase the speed and accuracy of diagnosis. Additionally, Federated learning makes multi-institutional/multi-city AI-based collaborations possible without sharing identifiable patient data. More powerful hardware designs - e.g., Edge and Quantum Computing- will facilitate the role of computing applications in TB. However, “Artificial Intelligence needs real Intelligence to guide it!” To have maximal impact, AI must use a holistic approach that incorporates time tested human wisdom gained over decades from the full gamut of TB, i.e., key imaging and clinical parameters, including prognostic indicators, plus bacterial and epidemiologic data. We propose a similar holistic approach at the level of national/international policy formulation and implementation, to enable effective culmination of TB’s endgame, summarizing it with the acronym “TB - REVISITED”.

Application of urodynamics combined with contrast-enhanced ultrasound in evaluation of the urinary tract in patients with low bladder compliance and vesicoureteric reflux who underwent bladder augmentation alone

We assessed the use of common urodynamics (CUD) combined with contrast-enhanced ultrasound (CEUS) to investigate the efficacy and durability of sigmoid cystoplasty alone in patients with low bladder compliance associated with vesicoureteric reflux (VUR). In this study, we recruited 25 patients with low bladder compliance and VUR who underwent bladder augmentation without antireflux surgery at our institutions between June 2017 and June 2021. The bladder condition and VUR grade were assessed preoperatively and postoperatively via CUD combined with CEUS. The mean follow-up period was 2.6 years. CUD showed significant improvement in bladder capacity and compliance and a decrease in intravesical pressure after sigmoid cystoplasty. CEUS demonstrated resolution of VUR compared with preoperative assessment. Of the 25 patients who had various degrees of reflux, VUR was eliminated in 18 patients and reduced to a lower grade in the remaining seven patients. CUD combined with CEUS is accurate and safe. They are invaluable and reliable tools for morphological and functional evaluations of the entire urinary tract in patients with low bladder compliance and VUR.

Contrast-enhanced voiding urosonography, a possible candidate for the diagnosis of vesicoureteral reflux in children and adolescents; a systematic review and meta-analysis

INTRODUCTION

The diagnostic value of contrast-enhanced voiding urosonography (ceVUS) in the diagnosis of vesicoureteral reflux (VUR) is still a subject of dispute.

OBJECTIVE

Assessing the diagnostic value of ceVUS in VUR, performing a systematic review and meta-analysis.

METHODS

An extensive search on Medline, Embase, Scopus and Web of Science databases was conducted by the end of 2020. The inclusion criteria were studies on the diagnostic value of ceVUS for VUR. Two independent researchers summarized the included articles and the findings were reported as area under the curve (AUC), sensitivity and specificity with a 95% confidence interval (95% CI).

RESULTS

Finally, the data of 36 articles were included in the present meta-analysis (2768 children). The VUS assessment showed that 1297 of the cases were true positives, 3661 were true negatives, 398 were false positives and 169 were false negatives. The AUC, sensitivity and specificity of ceVUS with the first-generation contrast agent in the diagnosis of VUR in children and adolescents were obtained as 0.97 (95% CI: 0.95, 0.98), 0.92 (95% CI: 0.86, 0.96) and 0.94 (95% CI: 0.95, 0.98), respectively. Moreover, AUC, sensitivity and specificity of ceVUS with the second-generation contrast agent were 0.97 (95% CI: 0.95, 0.98), 0.93 (95% CI: 0.86, 0.97) and 0.91 (95% CI: 0.86, 0.95).

CONCLUSION

The findings of the present study showed that diagnostic value of ceVUS with both first-generation and second-generation contrast agents for VUR, is in an excellent range. Although it seems that ceVUS may be applied as a radiation-free alternative to imaging techniques such as VCUG, the presence of 3% of false negatives in this test is a limitation. Since the lack of punctual management of VUR is associated with serious renal complications in children, future studies are recommended to be focused on the evaluation of the Benefit-risk evaluation of ceVUS.

The Spectrum of Parenchymal Changes in Kidneys Affected by Intrarenal Reflux, Diagnosed by Contrast-Enhanced Voiding Urosonography and DMSA Scan

PURPOSE

To describe the parenchymal defects in kidneys with intrarenal reflux (IRR) diagnosed using contrast-enhanced voiding urosonography (ceVUS) and ^99mTc-DMSA scintigraphy (DMSA scan).

MATERIALS AND METHODS

A group of 186 uretero-renal units (URUs) was analyzed using ceVUS and DMSA scans: 47 without vesicoureteral reflux (VUR) (group A) and 139 with VURs, comprising 73 VURs without (group B), and 66 with IRR (group C). VURs included non-dilating (grades I-II), mildly non-dilating (grade III), and non-dilating (grades IV-V) grades. The parenchymal changes were analyzed using a DMSA scan.

RESULTS

The median age for VUR diagnosis was 16.5 months in girls, and 8.5 months in boys (Z = 3.9; p = 0.001). IRR occurred in 51.4% of boys and in 25.9% of girls (χ² = 12.4; p < 0.001). The non-dilating VUR occurred in 44% of boys and 24.1% of girls (χ² = 7.7; p = 0.005). IRRs characterized upper and lower renal segments (81.8 and 63.6%) and middle segments (33.3%). Both incidence and increase in IRR correlated with the grade of VUR (p < 0.001). The incidence of reduced DMSA signal was statistically different among groups A + B and C, but not between groups A and B (χ² = 32.2; p < 0.001). No statistically significant relationship existed between the reduced DMSA signal and the grade of VUR in group C. The reduced DMSA signal appeared in 9.9% positions in kidneys from group A, 14% from group B, and 32% from group C. Out of all 118 IRRs, 38.1% had reduced and 61.9% had normal DMSA signal. Among 11 parenchymal scars found in all three groups, 2 belonged to group B, 9 to group C, while group A had no scars.

CONCLUSION

The parenchymal changes are the most prominent in the group with IRR, but they do not significantly differ among kidneys with different grades of VUR. VURs of higher grades are associated with a higher incidence of IRR and early clinical presentation. Scars can also appear in lower-grade VURs accompanied by IRR. Boys with VUR have earlier clinical presentation than girls, as they have significantly higher grades of VUR with a higher proportion of IRRs. Therefore, we suggest a subdivision of VURs into those with IRR and abundant parenchymal damage, and those without IRR and less parenchymal damage.

Congenital vaginal obstruction in a female with Cornelia de Lange syndrome: A case report

Cornelia de Lange syndrome (CdLS) is a rare genetic disease involving multiorgan systems that varies in clinical manifestations. Female genital abnormalities in patients with CdLS are rarely reported, and current guidelines for CdLS contain little information related to female genital abnormalities. We report a case of classic CdLS with an NIPBL gene pathogenic variant in a 4.5-year-old girl who experienced recurrent urinary tract infections (UTIs) with vesical tenesmus. Urogenital physical and imaging examinations revealed external vaginal orifice obstruction and bilateral vesicoureteral reflux (VUR). Vaginal diaphragm-like tissue resection and vaginal orifice plasty were performed on this patient. The symptoms of urination disorders and recurrent UTIs, as well as VUR grading, improved after relieving the vaginal obstruction during the operation. For female CdLS patients, especially those with VUR, it is necessary to check for genital abnormalities and perform timely treatment, which is of great significance in improving urination disorder symptoms, reducing resistance during voiding, decreasing the occurrence of secondary VUR, and controlling recurrent UTIs.

Contrast-enhanced voiding ultrasonography to detect intrarenal reflux in children: comparison with 99mTc-DMSA renal scans

Purpose

This study evaluated the diagnostic performance of contrast-enhanced voiding ultrasonography (CeVUS) for detecting intrarenal reflux (IRR) and the correlation between CeVUS-detected IRR sites and photon defect sites in acute ^99mTc-dimercaptosuccinic acid (DMSA) renal scans in pediatric patients.

Methods

Fifty-four kidneys from 27 patients (20 males and seven females; mean age, 5.6±4.1 months) who underwent CeVUS and acute DMSA renal scans for recurrent urinary tract infection (UTIs) or pyelonephritis were included. Pediatric experts compared the results of CeVUS with acute DMSA renal scans.

Results

Thirteen renal units (13/54, 24.1%) in 10 patients (nine males and one female; mean age, 6.3±3.7 months; age range, 0 to 13 months) showed vesicoureteral reflux and eight renal units (8/54, 14.8%) demonstrated IRR on CeVUS. Ten renal units in eight patients (six males and two females; mean age, 6.9±1.4 months; age range, 2 to 13 months) showed 19 photon defects on acute DMSA renal scans. Fifty-two renal units (96.3%) showed concordant results, and two renal units (3.7%) showed discordant results between CeVUS and acute DMSA renal scans. IRR accounted for 15/19 (78.9%) photon defects in eight renal units of seven patients using CeVUS. In a per-renal-unit analysis, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CeVUS were 80%, 100%, 100%, 95.7%, and 96.3%, respectively.

Conclusion

CeVUS showed good performance in detecting IRR, and the IRR sites detected by CeVUS closely correlated with photon defect sites in acute DMSA scans. CeVUS may play an important role in managing patients with recurrent UTIs or pyelonephritis with reduced radiation exposure.

Contrast-enhanced voiding urosonography, part 1: vesicoureteral reflux evaluation

Contrast-enhanced voiding urosonography (ceVUS) is a well-established, sensitive and safe ultrasound (US) modality for detecting and grading vesicoureteral reflux (VUR) and urethral imaging in children. Nearly three decades of remarkable advances in US technology and US contrast agents have refined ceVUS's diagnostic potential. The recent approval of Lumason/SonoVue in the United States, Europe and China for pediatric intravesical applications marked the beginning of a new era for this type of contrast US imaging. Consequently, the use of ceVUS in children has expanded to multiple places around the globe. In the first part of this review article, we describe the current experience in the use of ceVUS for VUR evaluation, with an emphasis on historical background, examination technique, image interpretation and diagnostic accuracy. In the second part, we will present the role of ceVUS for urethral imaging in children.

Pediatric contrast-enhanced ultrasound: optimization of techniques and dosing

When performing contrast-enhanced ultrasound (CEUS), ultrasound (US) scanner settings, examination technique, and contrast agent dose and administration must be optimized to ensure that high-quality, diagnostic and reproducible images are acquired for qualitative and quantitative interpretations. When carrying out CEUS in children, examination settings should be tailored to their body size and specific indications, similar to B-mode US. This review article details the basic background knowledge that is needed to perform CEUS optimally in children, including considerations related to US scanner settings and US contrast agent dose selection and administration techniques.

Pediatric contrast-enhanced ultrasound: shedding light on the pursuit of approval in the United States

For two decades, pediatric contrast US has been well accepted throughout Europe and other parts of the world outside the United States because of its high diagnostic efficacy and extremely favorable safety profile. This includes intravenous (IV) administration, contrast-enhanced US (CEUS) and the intravesical application, contrast-enhanced voiding urosonography (ceVUS). However, the breakthrough for pediatric contrast US in the United States did not come until 2016, when the U.S. Food and Drug Administration (FDA) approved the first pediatric indication for a US contrast agent. This initial approval covered the use of Lumason (Bracco Diagnostics, Monroe Township, NJ) for the evaluation of focal liver lesions via IV administration in children. A second pediatric indication followed shortly thereafter, when the FDA extended the use of Lumason for assessing known or suspected vesicoureteral reflux via intravesical application in children. Both initial pediatric approvals were granted without prospective pediatric clinical trials, based instead on published literature describing favorable safety and efficacy in children. Three years later, in 2019, the FDA approved Lumason for pediatric echocardiography following a clinical trial involving a total of 12 subjects at 2 sites. The story of how we achieved these FDA approvals spans more than a decade and involves the extraordinary dedication of two professional societies, namely the International Contrast Ultrasound Society (ICUS) and the Society for Pediatric Radiology (SPR). Credit also must be given to the FDA staff for their commitment to the welfare of children and their openness to compelling evidence that contrast US is a safe, reliable, radiation-free imaging option for our pediatric patients. Understanding the history of this approval process will impact the practical application of US contrast agents, particularly when expanding off-label indications in the pediatric population. This article describes the background of the FDA's approval of pediatric contrast US applications to better illuminate the potential pathways to approvals of future indications.

Contrast-enhanced voiding urosonography part 2: urethral imaging

Ultrasound (US) has been increasingly used as an important imaging tool to assess the urethra in children. The earliest reports of pediatric urethral sonography involved imaging the urethra in a non-voiding state, during physiological voiding of urine, and after instillation of saline. The introduction of US contrast agents has continued to improve visualization of urethral anatomy. Contrast-enhanced US of the urethra can be performed during the voiding phase of a standard contrast-enhanced voiding urosonography (ceVUS) exam or with retrograde instillation of a contrast agent, depending on the exam indication. Both techniques are well tolerated by children and provide accurate information about urethral pathology and periurethral soft tissues. This article reviews the technical aspects and imaging findings of urethral pathologies in children using contrast-enhanced US, both by the voiding and retrograde instillation techniques.

Safety assessment and diagnostic evaluation of patients undergoing contrast-enhanced urosonography in the setting of vesicoureteral reflux confirmation

BACKGROUND

Vesicoureteral reflux (VUR) represents a common pediatric anomaly in children with an upper urinary tract infection (UTI) and is defined as a retrograde flow of urine from the bladder into the upper urinary tract. There are many diagnostic options available, including voiding cystourethrography (VCUG) and contrasted-enhanced urosonography (ceVUS). ceVUS combines a diagnostic tool with a high sensitivity and specificity which, according to previous study results, was even shown to be superior to VCUG. Nevertheless, despite the recommendation of the EFSUMB, the ceVUS has not found a widespread use in clinical diagnostics in Europe yet.

MATERIALS AND METHODS

Between 2016 and 2020, 49 patients with a marked female dominance (n = 37) were included. The youngest patient had an age of 5 months, the oldest patient 60 years. The contrast agent used in ceVUS was SonoVue®, a second-generation blood-pool agent. All examinations were performed and interpreted by a single experienced radiologist (EFSUMB Level 3).

RESULTS

The 49 patients included in the study showed no adverse effects. 51% of patients (n = 26) were referred with the initial diagnosis of suspected VUR, while 49% of patients (n = 23) came for follow-up examination or to rule out recurrence of VUR. The vast majority had at least one febrile urinary tract infection in their recent medical history (n = 45; 91,8%).

CONCLUSION

ceVUS is an examination method with a low risk profile which represents with its high sensitivity and specificity an excellent diagnostic tool in the evaluation of vesicoureteral reflux, especially in consideration of a generally very young patient cohort.

Use of contrast-enhanced ultrasound in pediatrics

Although contrast-enhanced ultrasound has been shown to provide considerable benefits, particularly in pediatric patients, it is still used relatively rarely in Brazil. It has proven to be a safe technique, and adverse effects are rare. In this review, we address the technique and main applications of contrast-enhanced ultrasound in the pediatric population, including the evaluation of focal liver lesions, abdominal trauma, kidney grafts, liver grafts, bowel loops, and vesicoureteral reflux. It is important for pediatric radiologists to be acquainted with this promising tool, understanding its applications and limitations.

Assessment of distal ureteral and ureterovesical junction visualization on contrast-enhanced voiding urosonography

BACKGROUND

Contrast-enhanced voiding urosonography (CEVUS) uses intravesically administered microbubble contrast to detect vesicoureteral reflux (VUR) and urethral anomalies with ultrasound. Multiple studies have suggested CEVUS can replace voiding cystourethrogram (VCUG) as a radiation-free alternative. Analysis of the ureterovesical junction and ureters on VCUG documenting the ureterovesical junction position, ureteral duplication, periureteral diverticula and ureteroceles is important as anatomical variations may affect management and surgical approach.

OBJECTIVE

Our purpose was to assess distal ureteral and ureterovesical junction region visualization in children with VUR detected on CEVUS.

MATERIALS AND METHODS

CEVUS studies performed between June 2018 and March 2019 with reported VUR were retrospectively reviewed by two pediatric radiologists to confirm VUR and to qualitatively assess the ureterovesical junction region for each renal moiety using a 3-point scale for clear, limited or absent visualization of the distal ureter, ureterovesical junction, ureteral duplication, periureteral diverticula and ureteroceles.

RESULTS

Thirty-four studies with VUR on CEVUS were identified. Sixty-seven renal moieties were evaluated including a solitary kidney in one child. VUR was detected in 52 moieties by reader 1 and in 53 by reader 2. A single moiety with discrepancy between readers regarding VUR was excluded from statistical analysis. No diverticula were detected by either reader and one ureterocele was detected by both readers. Visualization of the ureterovesical junction was described as clear in 5/52, limited in 14/52 and absent in 33/52 refluxing renal moieties by reader 1 and as clear in 12/52, limited in 20/52 and absent in 20/52 by reader 2. The ureterovesical junction was clearly visualized in 5/52 (9.6%) by reader 1 and 12/52 (23.1%) by reader 2. The Kappa value of -0.29 (confidence interval [CI] -0.25, 0.21) reveals a lack of agreement between the readers for clear versus limited or absent ureterovesical junction visualization. Distal ureteral visualization was described as clear in 14/52, limited in 16/52 and absent in 22/52 refluxing renal moieties by reader 1 and as clear in 27/52, limited in 7/52 and absent in 18/52 by reader 2. The distal ureter was clearly visualized in 14/52 (26.9%) by reader 1 and 27/52 (51.9%) by reader 2. The Kappa of 0.43 (CI 0.22, 0.64) reveals moderate agreement between the readers for clear versus limited or absent distal ureteral visualization. Duplication of the renal collecting system was identified in 13/52 refluxing kidneys by reader 1 and 11/52 refluxing kidneys by reader 2. Visualization of ureteral duplication was described as clear in 9, limited in 4 and absent in 39 of 52 refluxing renal moieties by reader 1 and as clear in 9, limited in 2 and absent in 41 by reader 2. Ureteral duplication was clearly visualized in 9/52 (17.3%) by reader 1 and 9/52 (17.3%) by reader 2. Kappa of 0.87 (CI 0.68, 1) reveals high agreement between the readers for clear versus limited or absent identification of ureteral duplication.

CONCLUSION

The distal ureter and ureterovesical junction region frequently are not clearly visualized in refluxing renal moieties on CEVUS. Awareness of this limitation is important as there may be implications when evaluating patients for surgical management of VUR.

OUR EXPERIENCE WITH CONTRAST-ENHANCED VOIDING UROSONOGRAPHY

Vesicoureteral reflux (VUR) is one of the most common anomalies of the urinary system in children. Contrast-enhanced voiding urosonography (ceVUS) is one of the best methods in VUR diagnosis. This study compared characteristics associated with VUR specific images and categorized patients according to a particular VUR grade. The study included 183 children. VUR was detected in 38.9% of patients, mean age 1.7±1.1 years. Grade II VUR was most common (60.3%), followed by grade III (29.4%). Study results showed that VUR occurred irrespective of age, gender, previous ultrasound findings, causative agent, and severity of urinary tract infection (UTI). VUR was more common in children with recurrent UTI. In the group of children with the first UTI not caused by Escherichia coli or with recurrent UTI, boys more commonly suffered from severe VUR (grade IV-V; 66.7%), while girls suffered from moderate VUR (grade II-III; 100%). In this study, the incidence of VUR in prenatally diagnosed hydronephrosis was 28.6%. It is necessary to develop an algorithm for the treatment of children after UTI in Croatia, which should include ceVUS. All children with possible VUR should be referred to a specialized center where it is possible to perform ceVUS.

Contrast-enhanced voiding urosonography in the assessment of vesical-ureteral reflux: the time has come

Vesicoureteral reflux (VUR) is a pathological condition contradistinguished by monolateral or bilateral retrograde flow of urine from the bladder to the ureter and to the kidney. If not properly recognized and treated, VUR can potentially be associated to several complications such as recurrent infections and possible secondary scars with Chronic Kidney Disease (CKD). Furthermore, it represents an important risk factor for nephrovascular hypertension. During the last 20 years, the diagnostic approach to this entity has passed through several, drastic changes: indeed, since its introduction in 1994 contrast-enhanced voiding urosonography (ceVUS) has gradually accompanied the voiding cystourethrography (VCUG) as alternative imaging technique for the diagnosis and staging of VUR. Despite a large number of papers has strongly encouraged its use in clinical practice, due to the lack of ionizing radiations and its high sensitivity rate, to date almost all the guidelines only include the VCUG for VUR diagnosis. The introduction of technologically advanced US software and the approval of the intravesical administration of ultrasound contrast agents by the Food and Drug Administration (FDA) and by the European Medicine Agency (EMA) have to induce the Scientific Community to a deep revaluation of the role of ceVUS in the diagnosis and follow-up of VUR: urosonography might extensively replace VCUG as the reference method, reserving to cystourethrography a role in the most complex anatomic settings for pre-surgical evaluation.

Contrast-enhanced ultrasound using SonoVue mixed with oral gastrointestinal contrast agent to evaluate esophageal hiatal hernia: Report of three cases and a literature review

BACKGROUND

Due to a thicker abdominal wall in some patients, ultrasound artifacts from gastrointestinal gas and surrounding tissues can interfere with routine ultrasound examination, precluding its ability to display or clearly show the structure of a hernial sac (HS) and thereby diminishing diagnostic performance for esophageal hiatal hernia (EHH). Contrast-enhanced ultrasound (CEUS) imaging using an oral agent mixture allows for clear and intuitive identification of an EHH sac and dynamic observation of esophageal reflux.

CASE SUMMARY

In this case series, we report three patients with clinically-suspected EHH, including two females and one male with an average age of 67.3 ± 16.4 years. CEUS was administered with an oral agent mixture (microbubble-based SonoVue and gastrointestinal contrast agent) and identified a direct sign of supradiaphragmatic HS (containing the hyperechoic agent) and indirect signs [e.g., widening of esophageal hiatus, hyperechoic mixture agent continuously or intermittently reflux flowing back and forth from the stomach into the supradiaphragmatic HS, and esophagus-gastric echo ring (i.e., the “EG” ring) seen above the diaphragm]. All three cases received a definitive diagnosis of EHH by esophageal manometry and gastroscopy. Two lesions resolved upon drug treatment and one required surgery. The recurrence rate in follow-up was 0%. The data from these cases suggest that the new non-invasive examination method may greatly improve the diagnosis of EHH.

CONCLUSION

CEUS with the oral agent mixture can facilitate clear and intuitive identification of HS and dynamic observation of esophageal reflux.

Contrast-enhanced voiding urosonography for the diagnosis of vesicoureteral reflux and intrarenal reflux: a comparison of diagnostic performance with fluoroscopic voiding cystourethrography

Purpose

This study evaluated the diagnostic performance of contrast-enhanced voiding urosonography (ce-VUS) using a second-generation ultrasound contrast agent for the diagnosis of vesicoureteral reflux (VUR) and intrarenal reflux (IRR), and compared it with that of standard fluoroscopic voiding cystourethrography (VCUG).

Methods

Thirty-two consecutive children from April to October 2019 were included in this study. ce-VUS and VCUG were performed simultaneously by two operators with intravesical infusion of a mixture of ultrasound contrast medium, iodinated contrast medium and water. Two pediatric radiologists independently reviewed the ce-VUS and VCUG images and reported the presence and degree of VUR (grades I-V), and the presence and type of IRR.

Results

Twenty-seven of 63 urinary systems showed VUR. Interobserver agreement for VUR grading was very good for both examinations (κ=0.87; 95% confidence interval [CI], 0.82 to 0.92 for ce-VUS and κ=0.92; 95% CI, 0.87 to 0.96 for VCUG). The detection rate of VUR showed no significant difference between the two examinations (P=0.370). Four cases of VUR were missed on ce-VUS, while one case of VUR was missed on VCUG. All four false-negative cases on ce-VUS were grade 1 VUR. The two examinations showed very good agreement regarding VUR grading (κ =0.89; 95% CI, 0.81 to 0.96). IRR was more frequently detected with ce-VUS than with VCUG (10 cases with ce-VUS vs. 3 cases with VCUG, P=0.016).

Conclusion

ce-VUS showed very good agreement with VCUG for detecting grade 2 VUR and above, while grade 1 VUR was sometimes missed with ce-VUS. IRR was more frequently detected with ce-VUS than with VCUG.

Evaluation of the Diagnostic Value of Contrast-Enhanced Voiding Urosonography with Regard to the Further Therapy Regime and Patient Outcome-A Single-Center Experience in an Interdisciplinary Uroradiological Setting

Background and Objectives: Vesicoureteral reflux (VUR) describes a common pediatric anomaly in pediatric urology with a prevalence of 1-2%. In diagnostics, in addition to the gold standard of voiding cystourethrography (VCUG), contrast-enhanced urosonography (ceVUS) offers a radiation-free procedure, which, despite its advantages, is not yet widely used. In the present single-center study, subsequent therapeutic procedures and outcomes after ceVUS of 49 patients were investigated. The aim of the study is to investigate the efficacy of ceVUS with the intention of broader clinical implementation. Materials and Methods: Between 2016 and 2020, 49 patients were retrospectively included and received a ceVUS to evaluate VUR. With a distribution of 47:2 (95.9%), a clear female predominance was present. The age of the patients varied between 5 months and 60 years at the time of ceVUS. All examinations were all performed and subsequently interpreted by a single experienced radiologist (EFSUMB level 3). Results: Compared to intraoperative findings, ceVUS shows a sensitivity of 95.7% with a specificity of 100%. Allergic reactions to the contrast medium could not be observed. Conclusion: With its high sensitivity and intraoperative validation, ceVUS offers an excellent alternative to VCUG, the gold standard in the diagnosis of VUR. In addition, ceVUS is a radiation-free examination method with a low risk profile that offers an exceptional diagnostic tool in the diagnostic clarification of recurrent urinary tract infections with the suspected diagnosis of VUR and should also be included in the consideration of a diagnosis next to the established VCUG, especially in younger children.

Intrarenal Reflux in the Light of Contrast-Enhanced Voiding Urosonography

Purpose: The aim of this study was to analyze the incidence of intrarenal reflux (IRR) among vesicoureteral refluxes (VURs), diagnosed by contrast-enhanced voiding urosonography (ceVUS), to define VURs which are positive to IRR and their locations in the kidney. Materials and Methods: Seventy patients with VURs, including 103 uretero-renal units (URUs) with VURs of grades II-V (37 URUs were excluded because of renal anomalies or absence of VUR) were examined with ceVUS due to recurrent febrile UTI or first febrile UTI accompanied by abnormalities on renal ultrasonography. Patients were examined on GE Logiq S8 ultrasound machine, using second generation of ultrasound contrast agent. Results: Out of 103 VURs, 51 (49.51%) had IRR regardless the grade of VUR, showing increase in IRR incidence with VUR severity (p < 0.0001). The median age at the time of IRR diagnosis was 5 months (IQR, 3-14.3), whereas in patients without IRR, it was 15.5 months (IQR, 5-41.5), (p = 0.0069). IRR was most common in superior pole (80%), followed by inferior pole (62.7%), and middle segments (37%), and to all segments (27%) (p < 0.0001). Conclusion: In the present study, patients with IRR-associated VUR showed earlier clinical presentation. The distribution of IRRs corresponded to the natural distribution of composed papillae types II and III, while the incidence of IRR increased with severity of VUR. Further clinical studies may point to the importance of considering IRR in the future classification of VUR.

Impact of Implementing Contrast-Enhanced Ultrasound for Antegrade Nephrostogram After Percutaneous Nephrolithotomy

OBJECTIVES

To report results from a quality improvement (QI) project evaluating diagnostic performance, hospital resource use, and patient response data for postoperative contrast-enhanced ultrasound (CEUS) antegrade nephrostogram after percutaneous nephrolithotomy.

METHODS

For this Health Insurance Portability and Accountability Act-compliant, Institutional Review Board-approved study, QI data were deidentified and analyzed. On the first postoperative day after percutaneous nephrolithotomy, patients underwent both CEUS and fluoroscopic antegrade nephrostogram. For CEUS, 1.0 mL of Lumason (sulfur hexafluoride lipid type A microspheres; Bracco Diagnostics, Inc, Monroe Township, NJ) was injected via an indwelling nephrostomy tube, with ureteral patency confirmed by identifying intravesical ultrasound (US) contrast. Diagnostic performance for ureteral patency and contrast extravasation was calculated (with fluoroscopy as the reference standard). The examination time, room time, physician time, hospital costs, and patient response data were compared. The mean, standard deviation, 95% confidence interval, differences in mean, and 95% confidence interval of differences were calculated.

RESULTS

Eighty-one examinations were performed in 73 patients during the QI period. The sensitivity and specificity of CEUS for ureteral patency were 96% and 57%, respectively. There was no significant difference in time metrics between modalities, and the cost analysis showed lower direct and indirect costs for CEUS. Patient responses revealed lower levels of comfort for CEUS relative to fluoroscopy, without significant differences in reported pain or effort levels.

CONCLUSIONS

Contrast-enhanced US showed very high sensitivity for ureteral patency; the relatively low specificity may have resulted from false-negative results in fluoroscopy. The hospital costs and resource use of CEUS compared favorably to fluoroscopy. Contrast-enhanced US also offers inherent advantages, including portability and lack of ionizing radiation.

Contrast-enhanced voiding urosonography (CEVUS) as a novel technique for evaluation in a case of male urethral diverticulum

Male urethral diverticulum is an uncommon entity, the abnormality being more frequently encountered in females. The pathology may be congenital or acquired and the more frequent acquired type usually occurs following trauma. Afflicted patients usually lack specific symptoms, although in a few instances, symptoms of lower urinary tract obstruction, calculi, or infection may prevail. Imaging investigations utilizing a composite Retrograde urethrography (RGU)– Voiding cystourethrography (VCUG) protocol are accepted as standard approach and ultrasound is considered a secondary supplementary investigation. However, recent literature reports the utility of contrast-enhanced ultrasound (CEUS) as a novel technique in the evaluation of urinary bladder and urethra, for vesico-ureteric reflux (VUR) in children and for urethral diverticula in women. We report a case of acquired post-traumatic urethral diverticulum in an adult male patient and document a relatively unexplored novel application of contrast enhanced voiding uro-sonography (CEVUS) for the evaluation of this malady.

Contrast-enhanced voiding urosonography: A new, radiation-free, alternative method for imaging of urinary bladder and urethra in healthy dogs

Contrast-enhanced voiding urosonography (CE-VUS) has been generally considered as a promising tool to diagnose vesicoureteral reflux and abnormalities in lower urinary tract in human patients, especially in children. The purpose of this prospective study is to evaluate the quality of images of the urinary bladder and urethra obtained by CE-VUS using a second-generation ultrasound contrast agent (SonoVue®) in healthy dogs and to investigate the safety profile of SonoVue® after intravesical administration. Eighty-four CE-VUS examinations with SonoVue® were successfully performed in both unsedated (39/84) and sedated (45/84) dogs. Contrast-enhanced voiding urosonography examination of urinary bladder was technically successful in all (84/84) dogs. The image quality was not considered adequate in five (5/84) dogs including three dogs in whom layering of contrast media during filling phase was observed and two dogs with premature destruction of microbubbles. In these five dogs, the problem was readily recognized and corrected such that the procedure was still successfully undertaken. The assessment of the urethra during spontaneous micturition was successfully performed in all (84/84) dogs in whom voiding was elicited during the examination. No side effects were observed after intravesical application of SonoVue®. This study demonstrates that CE-VUS is a feasible and valuable technique to evaluate low urinary tract morphology and function in dogs. Based on our review of the literature, there are no published reports about the use of this method in dogs.

State-of-the-Art Renal Imaging in Children

Imaging modalities for diagnosing kidney and urinary tract disorders in children have developed rapidly over the last decade largely because of advancement of modern technology. General pediatricians and neonatologists are often the front line in detecting renal anomalies. There is a lack of knowledge of the applicability, indications, and nephrotoxic risks of novel renal imaging modalities. Here we describe the clinical impact of congenital anomalies of the kidneys and urinary tract and describe pediatric-specific renal imaging techniques by providing a practical guideline for the diagnosis of kidney and urinary tract disorders.

The learning curve of contrast-enhanced 'microbubble' voiding urosonography-validation study

INTRODUCTION

Vesicoureteral reflux (VUR) is a common pediatric urologic condition associated with urinary tract infection and pyelonephritis. It can be diagnosed via fluoroscopic voiding cystourethrogram (VCUG) and, more recently, contrast-enhanced voiding ultrasonography (ceVUS), which does not expose the patient to ionizing radiation. Voiding urosonography contrast agents used for the diagnosis of VUR have been widely available in Europe but were approved by the Food and Drug Administration for use in the United States only in 2016.

OBJECTIVE

The objective was to optimize a protocol and compare the diagnostic performance of ceVUS to fluoroscopic VCUG in an academic medical center naïve to previous use of contrast-enhanced voiding urosonography.

STUDY DESIGN

Thirty-nine patients referred for clinically indicated evaluation of VUR were enrolled between September 2016 and March 2017. Patients underwent contrast-enhanced ultrasonography with prediluted Lumason and under the same catheterization underwent fluoroscopic VCUG. Comparative grading was performed by pediatric radiologists on-site at the time of examination.

RESULTS

Reflux was observed in 16 of 39 patients (20 of 64 renal units) ranging from grades 1 through 5. VCUG and ceVUS were concordant for detecting reflux in 10 of 39 patients (14 of 84 renal units) and excluding reflux in 23 of 39 patients (64 of 84 renal units) (Fig. 1). Using contrast enhanced voiding urosonography, 1 of 20 renal units had high-grade and 2 of 20 renal units had low-grade reflux that was not found on fluoroscopy. Using fluoroscopy, 1 of 20 renal units had high-grade and 2 of 20 renal units had low-grade reflux that had not been found on ceVUS. Two of 20 renal units were upgraded from low-grade on ceVUS to high-grade on fluoroscopy. This corresponds to a Cohen's kappa of 0.72 (confidence interval [CI] 0.54-0.91) or 'moderate.'

DISCUSSION

During our investigation, we noted that there was a technical learning curve related to poor contrast mixing and the need to titrate the concentration of Lumason. However, over the course of the study, we were able to correct the technical aspects. Ultimately, our results showed good correlation between VCUG and Lumason ceVUS and only slightly less correlation than published studies by experienced centers. Future studies with voiding should allow for improved urethral visualization.

CONCLUSION

While there is a considerable learning curve to the implementation of ceVUS for the diagnosis of pediatric VUR, these technical aspects can be corrected. Even a center previously naïve to contrast-enhanced ultrasound technology can, over a short period of time, demonstrate good correlation between VCUG and ceVUS in the diagnosis of VUR. Translation of ceVUS into clinical practice is an alternative to VCUG for diagnosis of reflux, is feasible, and can eliminate the radiation exposure associated with a VCUG.

Comparison of diagnostic accuracy for fistulae at ultrasound and voiding cystourethrogram in neonates with anorectal malformation

BACKGROUND

Recently, it has been reported that anorectal malformation with rectourethral fistula in male neonates can be managed by primary neonatal reconstruction without colostomy. To prevent urethral injury during anorectoplasty, the fistula's location is important. To date, the use of voiding cystourethrograms to determine the presence and location of fistulas in neonates with anorectal malformations has not been studied.

OBJECTIVE

To compare the accuracy of ultrasound (US) and voiding cystourethrogram for determining the presence and location of fistulas in neonates with anorectal malformation.

MATERIALS AND METHODS

We included 21 male neonates with anorectal malformation with rectourethral fistula (n=16), rectovesical fistula (n=1) or no fistula (n=4) who underwent US and voiding cystourethrogram preoperatively on the day of surgery. Fistula imaging was classified into three grades (0-2), and grades 1-2 were considered fistula positive. We compared the imaging-based location of the fistula with surgical findings.

RESULTS

US performed significantly better than voiding cystourethrogram for determining the presence of fistulas (area under the receiver operating characteristic curve, 0.90 vs. 0.71, respectively; P=0.044) (diagnostic accuracy 85.7%, 95% confidence interval [95% CI] 63.7-97.0% and 52.4%, 95% CI 29.8-74.3%, respectively). In cases with fistulas detected by either modality, the accuracy of locating the fistula by US was 50.0% (95% CI 24.7-75.3%) and by voiding cystourethrogram was 100% (95% CI: 59.0-100%).

CONCLUSION

US accurately detected, but did not accurately locate, fistulas in neonates with anorectal malformation. When planning primary neonatal reconstruction of anorectal malformation without colostomy, voiding cystourethrogram could provide additional information about fistula location.

Effect of Reader and Patient Parameters on the Performance of Last-Image-Hold for Fluoroscopic Grading of Vesicoureteric Reflux

OBJECTIVE. The purpose of this study is to determine the effect of different reader and patient parameters on the degree of agreement and the rate of misclassification of vesicoureteric reflux grading on last-image-hold frames in relation to spot-exposed frames from voiding cystourethrography (VCUG) as well as to determine the nature of reflux misclassification on last-image-hold frames. MATERIALS AND METHODS. Blinded readers conducted a retrospective evaluation of last-image-hold and spot-exposed frames of the renal fossae from 191 sequential VCUG examinations performed during a five-year period. Kappa tests were used to determine the agreement between reflux gradings and to assess the impact of reader and patient parameters. Pearson product-moment correlations were used to evaluate the effect of patient parameters on reader level of certainty regarding reflux grading. RESULTS. We measured almost perfect overall agreement for more experienced readers and substantial overall agreement for less experienced readers. Point estimates of overall misclassification were less than 2% for more experienced readers and less than 4% for less experienced readers. The readers' level of certainty about reflux grading had a positive impact on agreement values and misclassification rates. Experienced readers' most common misclassification was assigning reflux a grade of 3 on a spot-exposed frame and a grade of 2 on an equivalent last-image-hold frame. Inexperienced readers' most common misclassification involved missing reflux altogether. CONCLUSION. Instances of grade 2 reflux on last-image-hold frames may warrant supplemental evaluation with spot-exposed frames. Otherwise, a reader's level of certainty regarding reflux grading on a last-image-hold frame may help determine whether a supplemental spot-exposed frame would be beneficial.

The evaluation of vesicoureteral reflux among children using contrast-enhanced ultrasound: a literature review

INTRODUCTION

Voiding cystourethrogram (VCUG) with fluoroscopy remains the gold standard for detection and evaluation of vesicoureteral reflux (VUR) among children. However, the ionizing radiation exposure remains a concern for this diagnostic modality. Recent studies have proposed using contrast-enhanced ultrasound as an alternative option for VUR screening and follow-up in children. The aim of the study was to review the literature of comparative studies that assessed the diagnostic accuracy of contrast-enhanced ultrasound compared with VCUG.

METHODOLOGY

A systematic literature search was performed on electronic medical literature databases in July 2017. Literature identification, screening, and assessment of eligibility were performed by five reviewers with a pediatric radiologist. Literature was summarized for the study population, contrast used, and ultrasound mode as well as the timing of comparative reference study being performed. The studies were clustered according to the kind of contrast used. Reported diagnostic accuracy was extracted from individual studies and summarized across the included studies using descriptive statistics of median and interquartile range (IQR).

RESULT

A total of 45 comparative studies were identified as eligible for the summary of the literature. Two generations of ultrasound contrast were identified in the available studies (first generation, Levovist and second generation, SonoVue). For the ultrasound studies using the first-generation contrast, the median sensitivity, regardless of the ultrasound mode, was 90.25 (IQR 83.25-97), and the median specificity was 93 (IQR 91.3-95.25). Among studies using the second-generation contrast, the median sensitivity was 86.26 (IQR 81.13-97), and the median specificity was 90.99 (IQR 84-98). No serious adverse events were reported in any of the studies.

CONCLUSION

Overall, this review highlights the application of contrast-enhanced ultrasound for its advantage of no exposure to ionizing radiation and diagnostic accuracy relatively comparable to VCUG in the evaluation of VUR. In addition to the functional evaluation of the VUR, it also provides an anatomic evaluation of the kidneys and bladder with ultrasound imaging. However, one should also note that this alternate procedure is highly operator dependent where diagnostic accuracy is excellent when the expertise is available.

Pediatric voiding cystourethrography: An essential examination for urologists but a terrible experience for children

Voiding cystourethrography is the most important fluoroscopic examination in pediatric urology for the investigation of lower urogenital tract diseases, such as vesicoureteral reflux or urethral stricture. However, this invasive procedure imposes a significant burden on children and their parents, and recently there has been a paradigm shift in the diagnosis and treatment of vesicoureteral reflux. In the 2011 revision, the American Academy of Pediatrics guidelines on urinary tract infection recommended abandoning routine voiding cystourethrography after the first febrile urinary tract infection. In 2014, the randomized intervention for children with vesicoureteral reflux study recommended discontinuation of routine continuous antibiotic prophylaxis for vesicoureteral reflux. The time is now ripe to radically reconsider indications for voiding cystourethrography and the procedure itself.

Diagnostic accuracy of contrast-enhanced voiding urosonogram using second-generation contrast with harmonic imaging (CEVUS-HI) study for assessment of vesicoureteral reflux in children: a meta-analysis

PURPOSE

To assess the diagnostic accuracy and safety of contrast-enhanced voiding urosonogram using second-generation contrast with harmonic imaging (CEVUS-HI) in detecting vesicoureteral reflux (VUR) among children.

METHODS

A systematic literature search was performed in March 2018. Relevant comparative studies from Medline, EMBASE, World of Science, Scopus, CENTRAL, WHO trial registry and Clinicaltrials.gov were identified and appraised using QUADAS-2. Diagnostic accuracy parameters were determined using VCUG as the reference standard. Adverse effects related to ultrasound contrast were summarized. The heterogeneity and inter-study variability were determined. After appropriate subgroup diagnostic accuracy parameters were investigated, summarizing receiver operator characteristics was constructed using the bivariate model meta-regression to determine the area under the curve (AUC).

RESULTS

A total of 12 studies with low-high risk of bias, including 1917 ureteral units from 953 patients were assessed for this meta-analysis. The included studies reported no serious adverse events associated with the ultrasound contrast. The pooled diagnostic accuracy parameters of CEVUS-HI in detecting VUR amongst children were: sensitivity 90.43 (95% CI 90.36-90.50), specificity 92.82 (95% CI 92.76-92.87), the calculated (+) likelihood-ratio 12.59 (95% CI 12.49-12.68), (-) likelihood-ratio of 0.103 (95% CI 0.102-0.104) and extrapolated pooled diagnostic odds-ratio was 122.12 (95% CI 120.75-123.49). Heterogeneity with interstudy variability was noted (p < 0.0001, I-squared > 70%). The AUC was determined to be 0.965 for VUR detection.

CONCLUSIONS

The pooled diagnostic accuracy parameters from low-moderate quality of evidence have illustrated that the CEVUS-HI study has an excellent safety profile and acceptable diagnostic accuracy. It may be considered as an alternative diagnostic modality for assessment of VUR among children.

Running water sound technique in contrast-based voiding cystourethrogram: A case-control study

BACKGROUND

An intervention that can reduce the patient void time during a voiding cystourethrogram (VCUG) procedure can reduce the total radiation dose to the patient. This is because a delay in voiding leads to a high number of intermittent screenings to monitor if voiding occurs. This study assessed the impact of running-water sound (RWS) upon patients' voiding parameters and fluoroscopy screening times during VCUG examinations among children and adults.

MATERIALS AND METHODS

A case-control study involving 252 patients was undertaken which consisted two groups (control and test) of adults and children. The test groups underwent VCUG with RWS technique while the control groups underwent the procedure normally. T-test was used to compare the study parameters between the two groups and a p-value less than 0.05 was interpreted as significant.

RESULTS

The mean screening times (s) for children who underwent VCUG with and without RWS were 17.15 ± 2.5s and 30.61 ± 5.1s respectively (p = 0.0024). For adults, the RWS technique recorded a mean screening time of 37.36 ± 4.4s while the non-RWS procedures recorded 49.80 ± 5.2s (p = 0.001). The participants who received RWS intervention also felt the urge to void earlier than those who received no RWS intervention. The differences were also statistically significant for both children and adults.

CONCLUSION

The study being one of the first in this subject area indicates that the application of RWS technique induces early urge of iodinated-contrast voiding, and reduces voiding and fluoroscopy screening times during VCUG among children and adults. This simple technique can potentially enhance current practice.

3D/4D contrast-enhanced urosonography (ceVUS) in children - is it superior to the 2D technique?

Background: By now, two-dimensional contrast-enhanced voiding urosonography (ceVUS) has become a well-established method for the diagnosis and treatment monitoring of vesicoureteral reflux in children, particularly after the recent approval for this application in children in the USA and in Europe. The introduction of three-dimensional static (3D) and real-time (4D) techniques with ultrasound contrast agents opens up new diagnostic opportunities for this imaging modality. Objective: To analyze whether 3D and 4D ceVUS is a superior technique compared to standard 2D ceVUS in diagnosing vesicoureteral reflux in children. Material and methods: The study included 150 patients (mean age 3.7 years) who underwent 2D and 3D/4D ceVUS for the diagnosis and grading of vesicoureteral reflux. Results: 2D ceVUS and 3D/4D ceVUS diagnosed the same number of vesicoureteral refluxes, however, there was a statistically significant difference in grading between the two methods. Performing 3D/4D ceVUS resulted in changing the initial grade compared to 2D ceVUS in 19 out of 107 refluxing units (17.76%) diagnosed. The 4D technique enabled a more conspicuous visualization of vesicoureteral reflux than the 3D technique. Conclusions: 2D ceVUS and 3D/4D ceVUS diagnosed the same number of vesicoureteral refluxes, however, there was a statistically significant difference in grading between the two methods. Thus 3D/4D ceVUS appears at least a valid, if not even a more conspicuous technique compared to 2D ceVUS.