Elucidation of Renal Scars in Children With Vesicoureteral Reflux Using Contrast-Enhanced Ultrasound: A Pilot Study

The correlation between ureteric orifice morphology and primary vesicoureteral reflux grade and the impact on the effectiveness of endoscopic reflux correction

INTRODUCTION

Early diagnosis and treatment of primary vesicoureteral reflux (VUR) are essential for preserving renal function.

OBJECTIVES

The study explored whether preoperative cystoscopic grading of refluxing ureteric orifices (UO) correlated with their shape in an institution with non-performance of hydrodistention of the UO in the diagnosis and grading of VUR. We also assessed the relationship between the UO shape and VUR grade with the effectiveness of endoscopic correction of primary VUR in children.

METHODS

This retrospective study included consecutive patients ≤15 years treated for primary VUR. The reflux grade was based on the results of preoperative voiding cystourethrography as mild, moderate, or severe.

RESULTS

Fifty-one patients with 77 renal refluxing units (RRU) underwent endoscopic treatment with Deflux®. VUR was bilateral in 51 % of patients. VUR was mild in 13 %, moderate in 53 %, and severe in 34 % of cases. The patients with mild and moderate VUR had stadium-shaped UOs in 60 % and 54 % RRUs, respectively. Horseshoe-shaped UOs constituted 42 % of UOs in patients with severe VUR, followed by 31 % of golf-hole UOs. The reflux resolution rate after the first endoscopic injection was 84 %. The preoperative VUR grade correlated with UOs shape (p < 0.001). No significant correlation between UOs configuration and the outcome of endoscopic treatment was seen (p = 0.452). The preoperative VUR grade negatively correlated with a favorable endoscopic treatment (p = 0.043).

DISCUSSION AND CONCLUSION

Our data indicate ureteral orifice shapes are closely related to preoperative VUR grade. There was no correlation between the UO configuration and the success rate of endoscopic treatment of VUR, in contrast to the significant negative correlation between the VUR grade and the success rate of endoscopic treatment.

Contrast-enhanced ultrasound in detection and follow-up of focal renal infections in children

Objective:

Focal renal infections in children have to be diagnosed early in order to enable an appropriate antibiotic treatment. The purpose of this paper was to investigate the efficacy and clinical utility of intravenous renal contrast-enhanced ultrasound (CEUS) as an alternative imaging method for the diagnosis and follow-up of focal renal infections in children.

Methods:

Fourteen children aged from 6 months to 17 years (mean 6.5 years) in whom focal renal infection was suspected were included in this retrospective study. All data were obtained from medical and imaging records of the patients.

Results:

CEUS was performed for the diagnosis in all 14 children and then also for follow-up in seven children with renal abscess. In three children enhancement pattern was concordant with focal nephritis and in four children CEUS excluded focal renal infection and the diagnosis of pseudolesion was confirmed.

Conclusion:

Renal CEUS was proven to be an efficient and self-sufficient imaging in diagnosis and further follow-up of focal renal infections in children. CEUS patterns of focal renal infections are described as well as relevant CEUS enhancement patterns important for differential diagnosis. Renal abscess follow-up algorithm with CEUS is suggested.

Advances in knowledge:

All clinically relevant imaging data was obtained by CEUS and no other imaging was necessary for the diagnosis and follow-up.

Microbubbles in the belly: optimizing the protocol for contrast-enhanced ultrasound of the pediatric abdomen

Intravenous contrast-enhanced ultrasound (CEUS) can serve as a diagnostic or problem-solving tool in pediatric imaging. CEUS of abdominal solid organs has been reported for a number of indications. The approach to the examination broadly falls into two categories: evaluation of a focal lesion or surveillance of an organ or organs for lesions or perfusion abnormalities. A consistent, technical imaging protocol for both of these clinical scenarios facilitates integration of routine use of CEUS in an imaging department. Here we review the CEUS imaging protocols for abdominal organs in children, including technical and solid-organ-specific considerations.

Is there a relationship between renal scarring and neutrophil-to-lymphocyte ratio in patients with vesicoureteral reflux?

OBJECTIVES

Vesicoureteral reflux (VUR) exacerbates the risk of renal scarring by establishing a ground for pyelonephritis. It is known that the inflammatory process is more influential than the direct damage caused by bacterial infection in the development of renal scars after pyelonephritis. Therefore, the present study aims to investigate the relationship between renal scarring and systemic inflammatory markers in patients with VUR.

MATERIAL AND METHODS

Hundred and ninety-two patients (116 females, 76 males) diagnosed with VUR were divided into two groups based on the presence or absence of renal scarring and into three groups according to the grade of VUR (low, moderate and high). Neutrophil count, lymphocyte count, mean platelet volume (MPV) and neutrophil-to-lymphocyte ratio (NLR) were compared among the groups.

RESULTS

Of the 192 patients, 102 had renal scarring. The age and gender distribution did not differ significantly between the groups with and without renal scarring (p > 0.05). However, the grade of reflux and lymphocyte count were significantly higher in the group with renal scarring (p < 0.05), and the NLR was significantly lower in the group with renal scarring (p < 0.05). The lymphocyte count was significantly higher (p < 0.05) and NLR was significantly lower in the high-grade VUR group (p < 0.05). However, MPV values did not differ significantly (p > 0.05) between the groups.

CONCLUSIONS

NLR can be used to predict renal scarring in patients with VUR, especially in the period of 3-6 months after the first attack of infection, and may even serve as a candidate marker for treatment selection. However, larger series and prospective studies are needed.

Contrast-enhanced ultrasound of the kidneys and adrenals in children

Pediatric applications of contrast-enhanced ultrasound (CEUS) are growing. Evaluation of the kidneys and adrenal glands in children using intravenous administration of US contrast agents, however, is still an off-label indication. Pediatric CEUS applications for kidneys are similar to those in adults, including ischemic disorders, pseudo- versus real tumors, indeterminate lesions, complex cystic lesions, complicated pyelonephritis, and abscesses. CEUS applications for evaluation of adrenal glands in children are limited, mainly focusing on the assessment and follow-up of adrenal trauma and the differentiation between an adrenal hemorrhage and a mass. This review addresses the current experience in pediatric CEUS of the kidneys and adrenal glands. By extrapolating the established knowledge for US contrast evaluations in the adult kidney to the pediatric context we can note opportunities for CEUS clinical use in children.

Contrast-enhanced ultrasound: a comprehensive review of safety in children

Contrast-enhanced ultrasound (CEUS) has been increasingly used in pediatric radiology practice worldwide. For nearly two decades, CEUS applications have been performed with the off-label use of gas-containing second-generation ultrasound contrast agents (UCAs). Since 2016, the United States Food and Drug Administration (FDA) has approved the UCA Lumason for three pediatric indications: the evaluation of focal liver lesions and echocardiography via intravenous administration and the assessment of vesicoureteral reflux via intravesical application (contrast-enhanced voiding urosonography, ceVUS). Prior to the FDA approval of Lumason, numerous studies with the use of second-generation UCAs had been conducted in adults and children. Comprehensive protocols for clinical safety evaluations have demonstrated the highly favorable safety profile of UCA for intravenous, intravesical and other intracavitary uses. The safety data on CEUS continue to accumulate as this imaging modality is increasingly utilized in clinical settings worldwide. As of August 2021, 57 pediatric-only original research studies encompassing a total of 4,518 children with 4,906 intravenous CEUS examinations had been published. As in adults, there were a few adverse events; the majority of these were non-serious, although very rarely serious anaphylactic reactions were reported. In the published pediatric-only intravenous CEUS studies included in our analysis, the overall incidence rate of serious adverse events was 0.22% (10/4,518) of children and 0.20% (10/4,906) of all CEUS examinations. Non-serious adverse events from the intravenous CEUS were observed in 1.20% (54/4,518) of children and 1.10% (54/4,906) of CEUS examinations. During the same time period, 31 studies with the intravesical use of UCA were conducted in 12,362 children. A few non-serious adverse events were encountered (0.31%; 38/12,362), but these were most likely attributable to the bladder catheterization rather than the UCA. Other developing clinical applications of UCA in children, including intracavitary and intralymphatic, are ongoing. To date, no serious adverse events have been reported with these applications. This article reviews the existing pediatric CEUS literature and provides an overview of safety-related information reported from UCA uses in children.

Comparison of Urinary Tract Dilatation and Society of Fetal Urology systems in the detection of vesicourethral reflux and renal scar

Purpose

The presence and degree of hydronephrosis is very important in the management of many diseases of the urinary tract. In this study, we aim to compare the sensitivity and specificity of 2 classification systems that are used for hydro-nephrosis grading in ultrasound, for reflux and scar detection. The classification systems were the Society of Fetal Urology (SFU) and Urinary Tract Dilatation (UTD).

Material and methods

Ultrasounds and dimercaptosuccinic acid scintigraphies (DMSA) of all patients who underwent voiding cystourethrogram (VCUG) due to urinary tract infection were examined retrospectively. DMSA was accepted for scar detection and VCUG for reflux detection as reference methods. SFU classification was used for hydronephrosis in ultrasound reports, and UTD classification was made over the reports. Sensitivity, specificity, and positive and negative predictive values of UTD and SFU classification systems for reflux and scar detection were calculated, and these 2 systems were compared.

Results

103 (39%) of the patients were male and 162 (61%) were female. Pathologies were detected in 192 (35%) of 530 kidneys in ultrasound. In 110 (42%) of the children, reflux was detected in VCUG. Scars in DMSA were detected in only 16% (44) of 266 kidneys. Sensitivity, positive and negative predictive values of the UTD classification system were statistically significantly higher than the SFU system for scar and reflux detection (p < 0.01).

Conclusions

If we use the UTD system in ultrasounds of patients with urinary tract infections, children reported as UTD 0 may not need VCUG, which reduces radiation exposure to children and the cost of the diagnostic interventions.

Diagnostic performance of contrast-enhanced ultrasound for acute pyelonephritis in children

The objective of our study was to evaluate the performance of renal contrast-enhanced ultrasound (CEUS) against the 99m-labeled dimercaptosuccinic acid (DMSA) scan and computed tomography (CT) in children for the diagnosis of acute pyelonephritis. We included children who underwent both renal CEUS and the DMSA scan or CT. A total of 33 children (21 males and 12 females, mean age 26 ± 36 months) were included. Using the DMSA scan as the reference standard, the sensitivity, specificity, positive predictive value, and negative predictive value of CEUS was 86.8%, 71.4%, 80.5%, and 80.0%, respectively. When CT was used as the reference standard, the sensitivity, specificity, positive predictive value, and negative predictive value of CEUS was 87.5%, 80.0%, 87.5%, and 80.0%, respectively. The diagnostic accuracy of CEUS for the diagnosis of acute pyelonephritis was 80.3% and 84.6% compared to the DMSA scan and CT, respectively. Inter-observer (kappa = 0.54) and intra-observer agreement (kappa = 0.59) for renal CEUS was moderate. In conclusion, CEUS had good diagnostic accuracy for diagnosing acute pyelonephritis with moderate inter- and intra-observer agreement. As CEUS does not require radiation or sedation, it could play an important role in the future when diagnosing acute pyelonephritis in children.

European Society of Paediatric Radiology abdominal imaging task force: recommendations for contrast-enhanced ultrasound and diffusion-weighted imaging in focal renal lesions in children

Contrast-enhanced ultrasound (CEUS) and diffusion-weighted imaging (DWI) are safe, repeatable imaging techniques. The aim of this paper is to discuss the advantages, technical factors and possible clinical applications of these imaging tools in focal renal lesions in children.

Renal scarring following urinary tract infections in children

Urinary tract infection (UTI) is the most common bacterial infection seen in younger age group children. The most common risk factor for renal scarring in children with post-UTI is vesicoureteral reflux (VUR). This study looked at renal scarring following UTI in children by dimercaptosuccinic acid (DMSA) scan. It is a cross-sectional time bound study done among 40 infants and children with UTI for a period of 24 months. Their clinical presentation and laboratory data, including micturating cystourethrogram, were documented. DMSA scan, done during the follow-up, established the presence of renal scars if any. UTI was more common in males. Children with history of recurrent UTI had renal scarring. Statistical significance was noted when first and recurrent attacks of UTI were compared for clinical and diagnostic characteristics like Escherichia coli UTI (p = 0.007), increasing grades of VUR (p = 0.006) and renal scar formation (p = 0.041). The study concluded that the high grades of antenatal hydroureteronephrosis (100%), febrile UTI (34%), younger age group (67.5%) and E. coli UTI (86%) were more associated with recurrent attacks of UTI and renal scarring. DMSA, being the non-invasive test, is better proven to be an investigation of choice than other invasive modalities for follow-up of children with recurrent attacks of UTI.

Vesicoureteral Reflux and Renal Scarring in Infants After the First Febrile Urinary Tract Infection

Introduction

The objective of this research was to determine whether vesicoureteral reflux(VUR) was associated with evolution to renal scarring (RS) following a febrile urinary tract infection (UTI) in infants.

Materials and methods

Our research included 100 infants, ages up to 1 year with a first febrile UTI. The diagnostic was based on results of: laboratory findings, ultrasonography (USG), voiding cystourethrography (VCUG) and initial and control renal scintigraphy (DMSA renal scan) withtechnetium^99mTcsuccimer (dimercaptosuccinic acid), to assess the acute pyelonephritis (APN), VUR and RS.

Results

APN was proven with DMSA renal scan in 66 (66%) infants. Twenty-two infants (33.3%) had VUR in-group of patients with APN. On the control DMSA scan, performed 6 months after the first DMSA, the presence of RS was found in 18 (27.27%) infants. In infants with renal scars VUR were discovered in 9 of them (50%).

Conclusions

The pathogenesis of RS after febrile UTI in young children is multifactorial. Children with VUR have an increased risk for APN and RS. However, VUR is not the only precondition for RS. Creating a renal scarring cannot be imagined without the inflammatory process of the upper urinary system. Therefore, early detection and treatment of febrile UTIs in children and identify children at risk for RS are of primary importance.

Prenatal and postnatal urinary tract dilation: advantages of a standardized ultrasound definition and classification

Urinary tract dilatation is identified sonographically in 1-2% of fetuses and reflects a spectrum of possible nephro-uropathies. There is significant variability in the clinical management of individuals with prenatal urinary tract dilatation to postnatal urinary pathologies, because of a lack of consensus and uniformity in defining and classifying urinary tract dilation. Ultrasonography is the first step to screen and diagnose kidneys and the urinary tract diseases of the children. The need for a correct ultrasound approach led to the realization of algorithms aimed at standardizing the procedures, the parameters and the classifications. Our objective was to highlight the strengths of the Classification of Urinary Tract Dilation (UTD) suggested by the Consensus Conference which took place in 2014 with the participation of eight Scientific Societies and was subsequently published on the Journal of Pediatric Urology. Before its spread out, the definition of UTD was not uniform and the ultrasonographic measurements were not clearly defined, leading to misunderstandings between physicians. The Classification by the Consensus Conference of 2014 represents a revolutionary tool for the diagnosis and management of UTD. Furthermore, the parameters suggested by the classification proposed are applicable for both prenatal and postnatal classification, ensuring a correct follow-up in children with UTD whose diagnosis had been already made during pregnancy.