Effects of Intrarenal Reflux on Renal Growth in Children With Grades III-V Primary Vesicoureteral Reflux.

The phenomenon of intrarenal reflux (IRR) has been considered a crucial link between vesicoureteral reflux (VUR) and segmental scarring. We conducted a study on renal length in 104 children diagnosed with Grades III-V VUR, with or without IRR, using contrast-enhanced voiding urosonography (ceVUS). The patients were divided into two treatment groups: the conservative antibiotic prophylaxis (CAP) group and the operation group, which were further categorized into two subgroups: the IRR group and the non-IRR group. Our findings revealed an incidence rate of 35.96% (41/114) for IRR occurrence, with 43.42% (33/76) occurring in upper renal segments, 32.89% (25/76) in lower segments, and 23.68% (18/76) in middle segments. In the CAP group where the effects of IRR persisted, the renal growth observed was as follows: IRR group-0.19 ± 0.13 cm; non-IRR group-0.39 ± 0.23 cm; contralateral negative group-0.66 ± 0.35 cm; control group-0.46 ± 0 .25 cm respectively (P < .05). In the operation group, where the effects of IRR were eliminated, the renal growth for the IRR group, non-IRR group, contralateral negative group, and control group was 0.46 ± 0.22 cm, 0.54 ± 0.31 cm, 0.67 ± 0 .42 cm, and 0.36 ± 0.17 cm respectively (P < .005). In conclusion, the presence of IRR can impact renal growth in children diagnosed with Grades III-V primary VUR. Following surgical intervention, the IRR kidney does not exhibit catch-up growth; however, it demonstrates parallel growth alongside the unaffected kidney. Conversely, the non-IRR kidney experiences catch-up growth. Therefore, for children presenting with Grades III-V primary VUR combined with IRR, a more aggressive treatment approach such as surgery is recommended.

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

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

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

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

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.

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.

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.

Starting a pediatric contrast ultrasound service: made simple!

The addition of contrast US to an existing pediatric US service requires several preparatory steps. This overview provides a guide to simplify the process. Initially, it is important to communicate to all stakeholders the justifications for pediatric contrast US, including (1) its comparable or better diagnostic results relative to other modalities; (2) its reduction in procedural sedation or anesthesia by avoiding MRI or CT; (3) its reduction or elimination of radiation exposure by not having to perform fluoroscopy or CT; (4) the higher safety profile of US contrast agents (UCA) compared to other contrast agents; (5) the improved exam comfort and ease inherent to US, leading to better patient and family experience, including bedside US exams for children who cannot be transported; (6) the need for another diagnostic option in light of increasing demand by parents and providers; and (7) its status as an approved and reimbursable exam. It is necessary to have an UCA incorporated into the pharmacy formulary noting that only SonoVue/Lumason is currently approved for pediatric use. In the United States this UCA is approved for intravenous administration for cardiac and liver imaging and for vesicoureteric reflux detection with intravesical application. In Europe and China it is only approved for the intravesical use in children. All other applications are off-label. The US scanner needs to be equipped with contrast-specific software. The UCA has to be prepared just before the exam and it is important to strictly follow the steps as outlined in the packaging inserts in order to prevent premature destruction of the microbubbles. The initial training in contrast US is best focused on the frontline staff actually performing the US studies; these might be sonographers, pediatric or interventional radiologists, or trainees. It is important from the outset to educate the referring physicians about contrast US. It is helpful to participate in existing contrast US courses, particularly those with hands-on components.

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.

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.

[Sensitivity of voiding urosonography as a function of the number of the cyclic bladder fillings]. / Sensitivität der Miktionsurosonographie in Abhängigkeit von der Anzahl der zyklischen Blasenfüllungen.

BACKGROUND: Vesicoureteral reflux (VUR) can occur intermittently. Cyclic testing of VUR (observation of multiple phases of filling and micturition) increases the detection rate of VUR, as has been shown in studies which have generally used a two-cycle test period. OBJECTIVES: How large is the dependence of the sensitivity in voiding urosonography (VUS) on the number of observed cycles when more than two cycles are observed in a larger number of patients? How many cycles should be observed in order to achieve sufficient sensitivity? PATIENTS AND METHODS: The study population consisted of 302 patients (225 female, average age 2.5 years [range 1 month-17 years]; 77 male, average age 6 months [range 1 month-2.5 years]) with 607 kidney-ureter units (KUU), examined in a pediatrican practice from 05 January 2016 to 31 December 2019. The examinations were performed by contrast-enhanced color Doppler voiding urosonography using the ultrasound contrast agent SonoVue® (Bracco Imaging, Milan, Italy) for an average of 3.14 cycles and, in the case of undetectable VUR, for an average of 3.5 cycles (range 1-6 cycles). RESULTS: In all, 118 of 302 patients were found to have VUR. In terms of KUU, 163 of 607 KUU exhibited reflux. VUR occurred intermittently in 32.5% of KUU. Depending on the number of cycles observed, there was a significant increase in sensitivity of the VUS. Using the observation of five cycles as a reference for the sensitivity, the following values are obtained: 1 cycle = 82.2%, 2 cycles = 87.7%, 3 cycles = 96.3%, 4 cycles = 98.8%, 5 cycles = 100%. CONCLUSIONS: To achieve a sensitivity of 96% in detecting VUR, three cycles must be observed. If less than three cycles are observed, the sensitivity shows a marked decrease.

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.

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.

Voiding urosonography and voiding cystourethrography in primary vesicoureteral reflux associated with mild prenatal hydronephrosis: a comparative study.

BACKGROUND: Contrast-enhanced harmonic voiding urosonography has been introduced as a sensitive, radiation-free imaging method for the diagnosis of vesicoureteric reflux. OBJECTIVE: To evaluate the occurrence/severity of vesicoureteric reflux in infants with mild prenatal hydronephrosis comparing voiding cystourethrography and voiding urosonography. MATERIALS AND METHODS: Sixty infants with prenatal hydronephrosis were studied (anteriοposterior pelvic diameter 5-9 mm on ultrasound [US] at gestational weeks 21-30). Postnatal US was performed within the first month of life, as well as voiding cystourethrography and contrast-enhanced voiding urosonography at 1.5-2.5 months at the same session. RESULTS: Vesicoureteric reflux was diagnosed on at least one modality in 19/60 (32%) infants, and more often on contrast-enhanced voiding urosonography (18/60, 30%) than on voiding cystourethrography (8/60, 13%), P=0.046. Among girls, reflux was more often seen on contrast-enhanced voiding urosonography (6/16, 38%) than on voiding cystourethrography (1/16, 6%), P=0.03. Vesicoureteric reflux missed by voiding cystourethrography was more severe (Grades I, II and III in one, nine and four kidney-ureter-units, respectively), compared with a single case missed by contrast-enhanced voiding urosonography (Grade I in one kidney-ureter-unit). CONCLUSION: In the absence of a reference standard, our results imply that voiding cystourethrography might underdiagnose reflux, and/or contrast-enhanced voiding urosonography may overdiagnose reflux.

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.

Potential causes of insufficient bladder contrast opacification and premature microbubble destruction during contrast-enhanced voiding urosonography in children.

Contrast-enhanced voiding urosonography (ceVUS) has been recognized as a child-friendly examination with high diagnostic accuracy for vesicoureteric reflux detection. A single bolus and the infusion techniques of ceVUS are described. Insufficient bladder contrast opacification during the filling phase and premature destruction of SonoVue microbubbles might occur. Data regarding SonoVue's features, doses, bladder contrast opacification, US bladder parameters, urine catheter, antibiotic prophylaxis, and childrens behaviors were collected to discover the possible causes of the contrast vanishing observed during bladder filling in 10% of examinations and in the later phase of ceVUS in 5% of examinations. An updated ceVUS examination protocol is suggested.

Contrast-enhanced voiding urosonography (ceVUS) with the intravesical administration of the ultrasound contrast agent Optison™ for vesicoureteral reflux detection in children: a prospective clinical trial.

BACKGROUND: Contrast-enhanced voiding urosonography (ceVUS) is widely used outside the United States to diagnose vesicoureteral reflux (VUR) in children and is highly sensitive while avoiding exposure to ionizing radiation. At the onset of this study, two ultrasound (US) contrast agents were available in the United States. Pediatric safety data for intravenous administration was published for one, Optison™. OBJECTIVE: This study aimed to evaluate the diagnostic performance and safety of ceVUS using Optison™ and compare its diagnostic efficacy with voiding cystourethrogram (VCUG) for VUR detection and grading in children. MATERIALS AND METHODS: The United States Food and Drug Administration and institutional Investigational New Drug authorizations were obtained to conduct a prospective comparative study of ceVUS with Optison™ and VCUG. CeVUS was performed with intravesical administration of 0.2% Optison™/normal saline solution. A standard VCUG followed. Safety assessment included physical examination, and heart rate, pulse oximetry and adverse reactions monitoring before, during and immediately after the examinations. A follow-up questionnaire was completed by telephone 48-h after the studies. RESULTS: Sixty-two pelviureteric units were studied in 30 patients with a mean age of 3.5 years (range: 0.1-17 years) including 21 girls and 9 boys. No severe adverse events occurred. All patients had normal heart rate and blood oxygenation saturation prior to, during and after the studies. At the 48-h follow-up, one patient (3.3%) reported transient dysuria. Taking the VCUG as the reference standard, ceVUS had a sensitivity of 91.7% (95%; confidence interval [CI]: 61.5%-99.8%) and specificity of 98% (95%; CI: 89.4%-99.9%). The concordance between ceVUS and VCUG for VUR detection and grading was 84.3% and 81.8%, respectively. VUR grades were discrepant in 4/11 refluxing pelviureteric units, with VCUG upgrading VUR in 2. CONCLUSION: Detection of VUR with Optison™ ceVUS was comparable to VCUG without exposure to ionizing radiation. CeVUS with Optison™ is a well-tolerated diagnostic procedure with a favorable safety profile.

Vesicoureteral refux detection in children: a comparison of the midline-to-orifice distance measurement by ultrasound and voiding urosonography.

BACKGROUND: Due to the questionable clinical role of vesicoureteral reflux (VUR) and the search for noninvasive, radiation-free procedures sufficiently reliable to detect VUR, we compared the correlation between the midline-to-orifice distance (MOD) measured by ultrasonography (US) and echo-enhanced voiding urosonography (VUS) for detecting VUR in children. The aim of the study was to determine whether measuring MOD by US could be a reliable predictor of VUR in children. METHODS: A total of 116 children, aged 0.25-84 months, with 232 potentially refluxing units were investigated simultaneously by measuring the MOD and performing VUS. Indications for cystography were urinary tract infection and follow-up of a previously detected VUR. VUS was performed after the MOD measurement. The results were analyzed with VUS as the reference method. RESULTS: The MOD was significantly larger in VUR grade III (10.7 mm; p = 0.003) and VUR grade II (9.9 mm; p = 0.001) refluxing units than in non-refluxing units (7.8 mm), even when controlling for the estimated volume/expected maximal capacity (Vest/Vmax) ratio. A MOD cutoff value of 7.4 mm was chosen as a predictor of either the presence or absence of VUR; the sensitivity and specificity of this cutoff measurement for VUR detection were found to be 89 and 24%, respectively. CONCLUSIONS: Despite the statistically significant difference between the MOD of refluxing versus non-refluxing units identified in our study, the MOD measurement needs further evaluation to determine its potential value as a diagnostic tool for the detection of VUR.

Intrarenal Reflux: Diagnosis at Contrast-Enhanced Voiding Urosonography.

Vesicoureteral reflux (VUR) is a childhood condition that is usually diagnosed by fluoroscopic voiding cystourethrography (VCUG). Intrarenal reflux (IRR) of infected urine is believed to play an important role in the pathogenesis of reflux-associated pyelonephritis and subsequent parenchymal scarring and is traditionally depicted by fluoroscopic VCUG. This case series describes the phenomenon of IRR occurring in association with VUR in 4 children as depicted by contrast-enhanced voiding urosonography. The ability of contrast-enhanced voiding urosonography to show IRR when it occurs in conjunction with VUR compares favorably to that of fluoroscopic VCUG.

Residual intravesical iodinated contrast: a potential cause of false-negative reflux study at contrast-enhanced voiding urosonography.

A 9-month-old girl underwent conventional cyclic voiding cystourethrography (VCUG) followed immediately by cyclic contrast-enhanced voiding urosonography (ceVUS). Although the VCUG showed unilateral grade II reflux, the ceVUS showed no reflux. Images from the ceVUS showed posterior dependent layering of the denser iodinated contrast in the bladder. This layering likely prevented reflux of US microbubbles resulting in a false-negative ceVUS. To our knowledge, this potential pitfall has not yet been reported.

Voiding urosonography: Contrast-enhanced ultrasound cystography to diagnose vesico-ureteric reflux: A pilot study.

We report two children with hydronephrosis, in whom we have utilized voiding urosonography (VUS) in the evaluation of vesico-ureteric reflux. With wider availability of ultrasound contrast agents and high-end ultrasound machines, VUS is likely to become a popular tool to diagnose or exclude VUR.