Imaging in childhood urinary tract infections: time to reduce investigations

Imaging of Vesicoureteral Reflux: AJR Expert Panel Narrative Review

Vesicoureteral reflux (VUR) is a common congenital anomaly of the urinary tract that can present with collecting system dilation or as a febrile infection. VUR can lead to permanent renal sequelae requiring surgery but can also spontaneously resolve without complication. Therefore, recognizing patient populations who warrant imaging for screening, confirmation, or ongoing surveillance for VUR is important, as is avoiding overdiagnosis. In the appropriate patient populations, an accurate diagnosis of VUR allows early treatment and prevention of pyelonephritis and scarring. Various imaging modalities are available to diagnose and grade VUR, including voiding cystourethrography, radionucleotide cystography, and contrast-enhanced voiding urosonography (ceVUS). The objective of this article is to summarize the current understanding of VUR diagnosis and management and to discuss these imaging modalities' strengths and pitfalls. Considerations include indications for VUR imaging, patient preparation, conduct of the examination, issues related to radiologic reporting, and cost-effectiveness. An emphasis is placed on ceVUS, which is the most recently introduced of the three imaging modalities and is receiving growing support among pediatric radiologists.

Renal scars in children with febrile urinary tract infection - Looking for associated factors

INTRODUCTION

Febrile urinary tract infection (UTI) is a common childhood infection related to renal scarring and potentially long-term complications like chronic kidney disease. It would be of great benefit to find a correlation between easy-accessible factors in the acute phase of a febrile UTI and the development of renal scar formation and/or decreased renal function in order to identify children at risk of future complications.

OBJECTIVE

The aim of this study was to identify factors associated with the development of decreased split renal function (DSRF) and/or permanent renal scar formation in children with febrile UTI.

STUDY DESIGN

The medical records of 212 Children aged 0 months to 15 years with febrile UTI admitted to The Pediatric Department of Lillebaelt Hospital, Kolding from January 2011 to September 2014 were systematically reviewed. We analyzed clinical, laboratory, and radiologic findings. Statistical analysis was performed to identify factors associated with renal scar formation and DSRF on nuclear imaging at 6 months follow-up.

RESULTS

A total of 113 medical records were eligible for further analysis, 99 girls and 14 boys, 34 patients younger than 12 months. In total 30 patients (26.5%) had an abnormal follow-up imaging (DSRF less than 45% and/or renal scarring). Nine patients (8%) had renal scarring. Four patients (3.5%) had renal scarring only, 21 patients (18.6%) had DSRF only, and five patients (4.4%) had both renal scarring and DSRF. Patients with renal scar formation on follow-up imaging had significantly higher C-reactive protein (CRP) than patients with no scarring (p < 0.01). CRP and absolute neutrophil count (ANC) was significantly higher in patients with abnormal follow-up imaging (p < 0.01 and p = 0.010), and these patients more often had positive nitrite in urine dipstick compared to patients with normal kidneys on follow-up (p = 0.048). Temperature above 38.5 °C and CRP >50 mg/L in combination were also associated with a higher risk of abnormal follow-up imaging (p = 0.016).

DISCUSSION

This study contributes with further knowledge to the ongoing debate regarding renal scarring but also reveals the possibility of associated factors for the development of DSRF following a febrile UTI in children. However, due to the retrospective design as well as the small number of events in our study definite conclusions on whether the above-mentioned factors are indeed prognostic for the development of renal scarring or DSRF following a febrile UTI can not be drawn.

Egyptian pediatric clinical practice guidelines for urinary tract infections in infants and children (evidence based)

Background

National evidence-based recommendations for diagnosis, treatment, imaging, and follow-up in urinary tract infection are crucial being a major health problem in pediatrics. Every region should follow international recommendations with respect to the disease local profile and available facilities for that area.

Methods

Based on AGREE II (the assessment tool of practice guidelines), Egyptian CGLs used *American Academy Pediatrics, *European Association Urology, European Society Pediatric Urology, and *Asian Association Urinary tract infections as its evidence-based references. Health questions were listed for evidence base answers adopted from selected CGLs after their permission. Key statements were approved by all members and further approved by the Egyptian Pediatric Guidelines Committee after local and international external peer reviewing.

Results

(1) Diagnosis recommendations: Urine culture with diagnostic colony counts is essential for diagnosis. Catheter samples are important for critical cases and non-toilet-trained cases especially when they show significant bacteriuria and pyuria. (2) Treatment plan included areas of debate as choice of antibiotic, oral versus intravenous, duration, antibiotic prophylaxis considering age, disease severity, recurrence, + risk factors, and imaging reports. (3) Imaging recommendations were tailored to suit our community. Renal bladder ultrasound is important for children with febrile UTI, due to the high prevalence of congenital anomalies of the kidney and urinary tract, paucity of prenatal ultrasound, and lack of medical documentation to reflect previously diagnosed UTI or US reports. We recommend renal isotopic scan and voiding cystography for serious presentation, high-risk factors, recurrence, and abnormal US. (4) Urological consultation is recommended: in urosepsis or obstruction, male infants < 6 months. Acute basal DMSA is recommended in congenital renal hypodysplasia. Six months post-infection, US and DMSA are recommended in severe pyelonephritis and vesico-ureteric reflux, where those with abnormal US or DMSA or both should have voiding cystography. (5) Follow-up recommendations include family orientation with hazards of noncompliance and monitoring at pregnancy.

Conclusion

Diagnosis and treatment show strong recommendations. Imaging depends on patient assessment. Referral to a pediatric nephrologist and urologist in complicated cases is crucial. Follow-up after the age of 16 years in adult clinics is important.

Asian guidelines for urinary tract infection in children

The followings are the level of evidence (LE) and grade of recommendation (GR) on pediatric UTI in Asia. Classification according to the sites of infection (lower versus upper tract), the number of episode (first versus recurrent), the severity (simple versus severe), or the existence of complicating factor (uncomplicated versus complicated) is useful to differentiate children with UTI whether they are at risk of renal damage or not (LE: 2, GR: B). Diagnosis of UTI requires both urinalysis that suggests infection and positive urine culture (LE:3, GR B). For pre-toilet trained children, urine specimen for culture should be collected by urethral catheterization or suprapubic aspiration. For toilet trained children, midstream clean catch urine is reliable (LE: 3, GR: A). Urine culture is considered positive if it demonstrates growth of a single bacterium with the following colony counts: (1) any growth by suprapubic aspiration, (2) >5 × 104 CFU/ml by urethral catheterization, or (3) >105 CFU/ml by midstream clean catch (LE:3, GR: B). For children with febrile UTI, renal and bladder ultrasonography (RBUS) should be routinely performed as soon as possible (LE: 3, GR: C). RBUS should be followed up 6 months later in children with acute pyelonephritis and/or VUR (LE: 3, GR: C). Acute DMSA scan can be performed when severe acute pyelonephritis or congenital hypodysplasia is noted on RBUS or when the diagnosis of UTI is in doubt by the clinical presentation (LE: 3, GR: C). Late DMSA scan (>6 months after the febrile UTI) can be performed in children with severe acute pyelonephritis, high-grade VUR, recurrent febrile UTIs, or abnormal renal parenchyma on the follow-up RBUS (LE: 3, GR: C). Top-down or bottom-up approach for febrile UTI is suggested for the diagnosis of VUR. For top-down approach, VCUG should not be performed routinely for children after the first febrile UTI. VCUG is indicated when abnormalities are apparent on either RBUS or DMSA scan or both (LE: 2, GR: B). VCUG is also suggested after a repeat febrile UTI (LE:2, GR: B). Appropriate antibiotic should be given immediately after urine specimen for culture has been obtained (LE:2, GR: A). Initiating therapy with oral or parenteral antibiotics is equally efficacious for children (>3 months) with uncomplicated UTI (LE: 2: GR: A). The choice of empirical antibiotic agents is guided by the expected pathogen and the local resistance patterns (LE: 2, GR: A). For children with febrile UTI, the total course of antibiotic therapy should be 7-14 days (LE: 2, GR: B). Circumcision may, but not definitively, reduce the risk of febrile UTI in males and breakthrough febrile UTI in males with VUR. Circumcision should be offered to uncircumcised boys with febrile UTI and VUR in countries where circumcision is accepted by the general population (LE: 3, GR: B), while in countries where childhood circumcision is rarely performed, other measures for febrile UTI/VUR should be the preferred choice (LE: 4, GR: C). Bladder bowel dysfunction (BBD) is one of the key factors of progression of renal scarring (LE: 2). Early recognition and management of BBD are important in prevention of UTI recurrence (LE:2, GR: A). Antibiotic prophylaxis to prevent recurrent febrile UTI is indicated in children with moderate to high grade (III-V) VUR (LE: 1b, GR: A). Surgical intervention may be used to treat VUR in the setting of recurrent febrile UTI because it has been shown to decrease the incidence of recurrent pyelonephritis (LE: 2, GR: B).

Urinary tract infection in pediatrics: an overview

OBJECTIVE

This review aimed to provide a critical overview on the pathogenesis, clinical findings, diagnosis, imaging investigation, treatment, chemoprophylaxis, and complications of urinary tract infection in pediatric patients.

SOURCE OF DATA

Data were obtained independently by two authors, who carried out a comprehensive and non-systematic search in public databases.

SUMMARY OF FINDINGS

Urinary tract infection is the most common bacterial infection in children. Urinary tract infection in pediatric patients can be the early clinical manifestation of congenital anomalies of the kidney and urinary tract (CAKUT) or be related to bladder dysfunctions. E. coli is responsible for 80-90% of community-acquired acute pyelonephritis episodes, especially in children. Bacterial virulence factors and the innate host immune systems may contribute to the occurrence and severity of urinary tract infection. The clinical presentation of urinary tract infections in children is highly heterogeneous, with symptoms that can be quite obscure. Urine culture is still the gold standard for diagnosing urinary tract infection and methods of urine collection in individual centers should be determined based on the accuracy of voided specimens. The debate on the ideal imaging protocol is still ongoing and there is tendency of less use of prophylaxis. Alternative measures and management of risk factors for recurrent urinary tract infection should be emphasized. However, in selected patients, prophylaxis can protect from recurrent urinary tract infection and long-term consequences. According to population-based studies, hypertension and chronic kidney disease are rarely associated with urinary tract infection.

CONCLUSION

Many aspects regarding urinary tract infection in children are still matters of debate, especially imaging investigation and indication of antibiotic prophylaxis. Further longitudinal studies are needed to establish tailored approach of urinary tract infection in childhood.

Urinary Tract Infection in Children

BACKGROUND

Urinary Tract Infection (UTI) is a common infection in children. Prompt diagnosis and appropriate treatment are very important to reduce the morbidity associated with this condition.

OBJECTIVE

To provide an update on the evaluation, diagnosis, and treatment of urinary tract infection in children.

METHODS

A PubMed search was completed in clinical queries using the key terms "urinary tract infection", "pyelonephritis" OR "cystitis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature and the pediatric age group. Patents were searched using the key terms "urinary tract infection" "pyelonephritis" OR "cystitis" from www.google.com/patents, http://espacenet.com, and www.freepatentsonline.com.

RESULTS

Escherichia coli accounts for 80 to 90% of UTI in children. The symptoms and signs are nonspecific throughout infancy. Unexplained fever is the most common symptom of UTI during the first two years of life. After the second year of life, symptoms and signs of pyelonephritis include fever, chills, rigor, flank pain, and costovertebral angle tenderness. Lower tract symptoms and signs include suprapubic pain, dysuria, urinary frequency, urgency, cloudy urine, malodorous urine, and suprapubic tenderness. A urinalysis and urine culture should be performed when UTI is suspected. In the work-up of children with UTI, physicians must judiciously utilize imaging studies to minimize exposure of children to radiation. While waiting for the culture results, prompt antibiotic therapy is indicated for symptomatic UTI based on clinical findings and positive urinalysis to eradicate the infection and improve clinical outcome. The choice of antibiotics should take into consideration local data on antibiotic resistance patterns. Recent patents related to the management of UTI are discussed.

CONCLUSION

Currently, a second or third generation cephalosporin and amoxicillin-clavulanate are drugs of choice in the treatment of acute uncomplicated UTI. Parenteral antibiotic therapy is recommended for infants ≤ 2 months and any child who is toxic-looking, hemodynamically unstable, immunocompromised, unable to tolerate oral medication, or not responding to oral medication. A combination of intravenous ampicillin and intravenous/intramuscular gentamycin or a third-generation cephalosporin can be used in those situations. Routine antimicrobial prophylaxis is rarely justified, but continuous antimicrobial prophylaxis should be considered for children with frequent febrile UTI.

Ureteral dilatation detected in magnetic resonance imaging predicts vesicoureteral reflux in children with urinary tract infection

Objective

Urinary tract infection (UTI), one of the most common bacterial infections occurring during infancy and early childhood, is frequently associated with vesicoureteral reflux (VUR). Although several guidelines recommend performing ultrasonography as a screening test, its utility is not adequate and appropriate screening tests are strongly desirable. In this study, we evaluate the use of magnetic resonance imaging (MRI) as a screening test for VUR in children with UTI.

Methods

We prospectively studied 108 patients with suspected UTI between April 2014 and March 2016. UTI was diagnosed on the basis of diffusion-weighted MRI (DW-MRI) and urine culture findings. We measured ureteral dilatation using MRI in 96 patients with UTI and assessed the relationship between ureteral dilatation in MRI and VUR in 46 patients who underwent voiding cystourethrography (VCUG).

Results

Among 108 patients, 88 and 8 were diagnosed with upper and lower UTI, respectively. Among 46 patients who underwent VCUG, 23 had VUR (14 low grade and 9 high grade). Patients with ureteral dilatation detected on MRI had VUR more frequently than those without ureteral dilatation (any grades VUR, 71% vs. 32%; P = 0.02; high-grade VUR, 38% vs. 2%, P = 0.007). Overall, ureteral dilatation findings on MRI achieved sensitivity 65.2% and specificity 73.9% as a screening test for VUR. In addition, DW-MRI achieved sensitivity 100% and specificity 81.8% in the diagnosis of upper UTI.

Conclusion

These findings suggested that MRI is a valuable tool for screening of VUR as well as diagnosis of upper UTI.

ACR Appropriateness Criteria® Urinary Tract Infection-Child

Urinary tract infection (UTI) is common in young children and may cause pyelonephritis and renal scarring. Long-term complications from renal scarring are low. The role of imaging is to evaluate for underlying urologic abnormalities and guide treatment. In neonates there is increased risk for underlying urologic abnormalities. Evaluation for vesicoureteral reflux (VUR) may be appropriate especially in boys because of higher prevalence of VUR and to exclude posterior urethral valve. In children older than 2 months with first episode of uncomplicated UTI, there is no clear benefit of prophylactic antibiotic. Ultrasound is the only study that is usually appropriate. After the age of 6 years, UTIs are infrequent. There is no need for routine imaging as VUR is less common. In children with recurrent or complicated UTI, in addition to ultrasound, imaging of VUR is usually appropriate. Renal cortical scintigraphy may be appropriate in children with VUR, as renal scarring may support surgical intervention. 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 include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Urinary tract infection in children: Diagnosis, treatment, imaging - Comparison of current guidelines

BACKGROUND AND OBJECTIVE

Urinary tract infection (UTI) is a frequent disorder of childhood, yet the proper approach for a child with UTI is still a matter of controversy. The objective of this study was to critically compare current guidelines for the diagnosis and management of UTI in children, in light of new scientific data.

METHODS

An analysis was performed of the guidelines from: American Academy of Pediatrics (AAP), National Institute for Health and Care Excellence (NICE), Italian Society of Pediatric Nephrology, Canadian Paediatric Society (CPS), Polish Society of Pediatric Nephrology, and European Association of Urology (EAU)/European Society for Pediatric Urology (ESPU). Separate aspects of the approach for a child with UTI, including diagnosis, treatment and further imaging studies, were compared, with allowance for recent research in each field.

CONCLUSIONS

The analyzed guidelines tried to reconcile recent reports about diagnosis, treatment, and further diagnostics in pediatric UTI with prior practices and opinions, and economic capabilities. There was still a lack of sufficient data to formulate coherent, unequivocal guidelines on UTI management in children, with imaging tests remaining the main area of controversy. As a result, the authors formulated their own proposal for UTI management in children.

Summary of the UAA-AAUS guidelines for urinary tract infections

Urinary tract infections, genital tract infections and sexually transmitted infections are the most prevalent infectious diseases, and the establishment of locally optimized guidelines is critical to provide appropriate treatment. The Urological Association of Asia has planned to develop the Asian guidelines for all urological fields, and the present urinary tract infections, genital tract infections and sexually transmitted infections guideline was the second project of the Urological Association of Asia guideline development, which was carried out by the Asian Association of Urinary Tract Infection and Sexually Transmitted Infection. The members have meticulously reviewed relevant references, retrieved via the PubMed and MEDLINE databases, published between 2009 through 2015. The information identified through the literature review of other resources was supplemented by the author. Levels of evidence and grades of recommendation for each management were made according to the relevant strategy. If the judgment was made on the basis of insufficient or inadequate evidence, the grade of recommendation was determined on the basis of committee discussions and resultant consensus statements. Here, we present a short English version of the original guideline, and overview its key clinical issues.

Nuclear Medicine in Pediatric Nephro-Urology: An Overview

In the context of ante-natally diagnosed hydronephrosis, the vast majority of children with a dilated renal pelvis do not need any surgical treatment, as the dilatation resolves spontaneously with time. Slow drainage demonstrated at Tc-99m-mercaptoacetyltriglycine (MAG3) renography does not necessarily mean obstruction. Obstruction is defined as resistance to urinary outflow with urinary stasis at the level of the pelvic-ureteric junction (PUJ) which, if left untreated, will damage the kidney. Unfortunately this definition is retrospective and not clinically helpful. Therefore, the identification of the kidney at risk of losing function in an asymptomatic patient is a major research goal. In the context of renovascular hypertension a DMSA scan can be useful before and after revascularisation procedures (angioplasty or surgery) to assess for gain in kidney function. Renal calculi are increasingly frequent in children. Whilst the vast majority of patients with renal stones do not need functional imaging, DMSA scans with SPECT and a low dose limited CT can be very helpful in the case of complex renal calculi. Congenital renal anomalies such as duplex kidneys, horseshoe kidneys, crossed-fused kidneys and multi-cystic dysplastic kidneys greatly benefit from functional imaging to identify regional parenchymal function, thus directing further management. Positron emission tomography (PET) is being actively tested in genito-urinary malignancies. Encouraging initial reports suggest that F-18-fluorodeoxyglucose (FDG) PET is more sensitive than CT in the assessment of lymph nodal metastases in patients with genito-urinary sarcomas; an increased sensitivity in comparison to isotope bone scans for skeletal metastatic disease has also been reported. Further evaluation is necessary, especially with the promising advent of PET/MRI scanners. Nuclear Medicine in paediatric nephro-urology has stood the test of time and is opening up to new exciting developments.

Renal ultrasound and DMSA screening for high-grade vesicoureteral reflux

BACKGROUND

Selection of the appropriate radiologic investigation in a child after first febrile urinary tract infection (UTI) remains a contentious issue. This report investigated the effectiveness of renal bladder ultrasound (RBUS) and late 6 month dimercaptosuccinic acid (DMSA) renal scan in the detection of high-grade vesicoureteral reflux (VUR) after first febrile UTI in infants aged <1 year.

METHODS

A total of 387 infants aged <1 year with first febrile UTI who completed diagnostic follow up consisting of RBUS, voiding cystourethrogram (VCUG) and late 6 month DMSA scan were enrolled in the study. The effectiveness of RBUS and DMSA scan in the detection of high-grade VUR, including cost and benefit were assessed.

RESULTS

Abnormal RBUS was identified in 95 infants (24.5%). VUR was identified on VCUG in 79 (20.4%), of whom eight (2.1%) had high-grade VUR (grade IV-V). Abnormal renal parenchyma was identified on late 6 month DMSA scan in 22 infants (5.7%). The sensitivity of abnormal RBUS and of late 6 month DMSA scan in the prediction of high-grade VUR was 50% and 87.5%, and the proportion of infants who avoided unnecessary VCUG was 75.5% and 94.3%, respectively.

CONCLUSIONS

Fifty percent of high-grade VUR was not identified on RBUS screening after first febrile UTI. Although late 6 month DMSA scan had higher sensitivity in the detection of high-grade VUR, with the added benefit of detection of renal scars, the practical application of this method was limited due to its high cost, radiation exposure and the associated delay in decision making.

Evaluation of new American Academy of Pediatrics guideline for febrile urinary tract infection

PURPOSE

To evaluate the practical applications of the diagnosis algorithms recommended by the American Academy of Pediatrics urinary tract infection (UTI) guideline.

METHODS

We retrospectively reviewed the medical records of febrile UTI patients aged between 2 and 24 months. The patients were divided into 3 groups: group I (patients with positive urine culture and urinalysis findings), group II (those with positive urine culture but negative urinalysis findings), and group III (those with negative urine culture but positive urinalysis findings). Clinical, laboratory, and imaging results were analyzed and compared between the groups.

RESULTS

A total of 300 children were enrolled. The serum C-reactive protein level was lower in children in group II than in those in groups I and III (P<0.05). Children in group I showed a higher frequency of hydronephrosis than those in groups II and III (P<0.05). However, the frequencies of acute pyelonephritis (APN), vesicoureteral reflux (VUR), renal scar, and UTI recurrence were not different between the groups. In group I, recurrence of UTI and presence of APN were associated with the incidence of VUR (recurrence vs. no recurrence: 40% vs.11.4%; APN vs. no APN: 23.3% vs. 9.2%; P<0.05). The incidence of VUR and APN was not related to the presence of hydronephrosis.

CONCLUSION

UTI in febrile children cannot be ruled out solely on the basis of positive urinalysis or urine culture findings. Recurrence of UTI and presence of APN may be reasonable indicators of the presence of VUR.

Meaning of ureter dilatation during ultrasonography in infants for evaluating vesicoureteral reflux

PURPOSE

To investigate the meaning of ureter dilatation during ultrasonography (US) in infants for evaluating vesicoureteral reflux (VUR).

MATERIALS AND METHODS

We retrospectively reviewed abdominal US images of infants who were diagnosed with urinary tract infection (UTI group) or only hydronephrosis without UTI (control group). Hydronephrosis (graded 0-4) and ureter dilatation (present or absent) were evaluated on each side with US. Voiding cystourethrography (VCUG) within 3 months time interval with US was also reviewed and VUR was graded (0-5) on each side. Hydronephrosis, ureter dilatation, and VUR were then compared between the two groups.

RESULTS

Four hundred and three infants (142 in the UTI group and 261 in the control group) were included and VCUG was performed in 129 infants (68 in UTI and 61 in control groups). VUR grades were not different between the two groups (p=0.252). Hydronephrosis grade was not related to VUR in either group (p>0.05). However, ureter dilatation had a significant relationship with VUR in the UTI group (p=0.015), even among patients with a high-grade VUR (p=0.005). Whereas, ureter dilatation was not associated with VUR in the control group (p=0.744). The relationship between ureter dilatation and VUR was different between the two groups for both all grades (p=0.014) and high-grade (p=0.004) VUR. Ureter dilatation had 66.7% sensitivity, 80.3% specificity, and 79.4% accuracy for evaluating high-grade VUR in the UTI group.

CONCLUSION

Ureter dilatation on US can be a helpful finding for detecting VUR in infants with UTI, but not infants without UTI.

Practical approach to screen vesicoureteral reflux after a first urinary tract infection

Introduction:

Vesicoureteral reflux (VUR) is a common pediatric urologic disorder. After the first urinary tract infection (UTI), imaging studies are recommended, starting with a renal ultrasound (RUS). Voiding cystourethrography (VCUG) and dimercaptosuccinic acid (DMSA) scan are the other main radiologic studies used to detect VUR. We evaluated the use of RUS as a screening method for VUR in children below 2 years of age, in order to avoid unnecessary VCUG.

Materials and Methods:

Medical records and imaging studies of infants (<2 years) who had their first UTI in a 6 year period were retrospectively reviewed. We evaluated the sensitivity, specificity, and negative predictive values of RUS and DMSA for diagnosing VUR.

Results:

Among 155 children (51% males) with their first UTI, 148 RUS were performed, 128 VCUG and 29 DMSA. VUR was detected in 21% patients; 14.5% low grade and 6.5% high grade. One hundred and twenty-one patients underwent both RUS and VCUG, 101 RUS were normal and 20 abnormal. Of the normal RUS 98% had no or low grade VUR. Among those with an abnormality on RUS 30% had high grade VUR (P < 0.001).

Conclusions:

After the first UTI in infants (<2 years) RUS is a good screening method for VUR. Among such shildren with a normal RUS, we do not recommend VCUG or DMSA. In our opinion, VCUG should be performed only in patients with abnormal findings in RUS or in recurrent UTI.

Paediatric urinary tract infections: a retrospective application of the National Institute of Clinical Excellence guidelines to a large general practitioner referred historical cohort

BACKGROUND

The National Institute for Clinical Excellence (NICE) is a United Kingdom nondepartmental public body accountable to the Department of Health. Before the introduction of the NICE guidelines in the United Kingdom most children younger than 1 year of age had a urinary tract ultrasound, cyclic micturating cystourethrogram and dimercaptosuccinic acid scintigraphy, the latter delayed 6 months post infection. Children older than 1 year had a urinary tract ultrasound only, and further imaging if necessary.

OBJECTIVE

Identify who would have been investigated had the NICE imaging strategy been used and who would not. Compare the diagnostic yield and patient outcome with the previous imaging protocol using our prospectively collected historical data.

MATERIALS AND METHODS

We applied the new imaging strategy to a historic cohort of 934 patients with a urinary tract infection (UTI) referred by general practitioners to a specialist children's hospital between 1996 and 2002.

RESULTS

Of the 934 patients referred, 218 would have been investigated according to the NICE guidelines. In total, there were 105 patients with abnormal imaging findings, and 44 of these (42%) would have been investigated under the NICE guidelines.

CONCLUSION

Applying the NICE guidelines to children presenting with UTI will reduce the number imaged by 77% and will lead to missed identification of 58% of imaging abnormalities in the group. The majority of these abnormalities may be important. While supporting conservative investigation protocols, we are concerned that many abnormalities might go undetected.

Does the ureteric jet Doppler waveform have a role in detecting vesicoureteric reflux?

Data reported in this issue of Pediatric Nephrology suggest that the ureteric jet Doppler waveform can predict the occurrence of vesicoureteric reflux (VUR). Many different methods are currently used to detect VUR, including traditional X-ray micturating cystourethrogram, indirect and direct nuclear imaging and contrast enhanced ultrasonography. These methods are invasive, do have some radiation burden and are also quite uncomfortable to paediatric patients. This relatively new non-invasive method is therefore of interest, but its efficacy needs to be confirmed in further studies and, in particular, in babies and infants before it can possibly be considered as a good method to provide clinical information on VUR. Once such studies have been performed, this method may also prove to be a useful approach to obtain modern knowledge on the occurrence of VUR in healthy children.

A review of guidelines for urinary tract infections in children younger than 2 years

CME EDUCATIONAL OBJECTIVES: 1.Review recent guidelines for diagnosis and treatment of urinary tract infections in children younger than 2 years.2.Review recent recommendations for imaging children with urinary tract infection.3.Understand rationale for recent treatment recommendations and prophylaxis of children with urinary tract infection.

Renal scar formation after urinary tract infection in children

Urinary tract infection (UTI) is a common bacterial illness in children. Acute pyelonephritis in children may lead to renal scarring with the risk of later hypertension, preeclampsia during pregnancy, proteinuria, and renal insufficiency. Until now, vesicoureteral reflux (VUR) has been considered the most important risk factor for post-UTI renal scar formation in children. VUR predisposes children with UTI to pyelonephritis, and both are associated with renal scarring. However, reflux nephropathy is not always acquired; rather, it reflects reflux-associated congenital dysplastic kidneys. The viewpoint that chronic kidney disease results from renal maldevelopment-associated VUR has led to questioning the utility of any regimen directed at identifying or treating VUR. Despite the recognition that underlying renal anomalies may be the cause of renal scarring that was previously attributed to infection, the prevention of renal scarring remains the goal of all therapies for childhood UTI. Therefore, children at high risk of renal scar formation after UTI should be treated and investigated until a large clinical study and basic research give us more information.

Screening high-grade vesicoureteral reflux in young infants with a febrile urinary tract infection

BACKGROUND

The lack of good evidence for improved outcomes in children and young infants with febrile urinary tract infection (UTI) after aggressive treatment for vesicoureteral reflux (VUR) has raised doubts regarding the need for routine voiding cystourethrography (VCUG), and the appropriate imaging evaluation in these children remains controversial.

OBJECTIVES

This prospective study aimed to determine whether abnormalities found on acute dimercaptosuccinic acid (DMSA) scan and ultrasound (US) can help indicate the necessity of voiding cystourethrography (VCUG) in young infants.

METHODS

For 3.5 years, all infants younger than 3 months presenting with first febrile UTI were prospectively studied. All infants were hospitalized and investigated using US (<3 days after admission), DMSA scan (<5 days after admission), and VCUG (7-10 days after antibiotic treatment) after diagnosis. The association among findings of US, DMSA scan, and VCUG were evaluated.

RESULTS

From 220 infants, there were abnormal results in 136 (61.8%) US and in 111 (50.5%) DMSA scans. By US, ten infants (4.5%) with abscess or structural abnormalities other than VUR were diagnosed. High-grade (III-V) VUR was present in 39 patients (17.7%). The sensitivities for high-grade VUR of renal US alone (76.9%) or DMSA scan alone (82.1%) were not as good as that of the "OR rule" strategy, which had 92.3% sensitivity and 94.3% negative predictive value.

CONCLUSIONS

To screen high-grade VUR in young infants with febrile UTI, US and acute DMSA scan could be performed first. VCUG is only indicated when abnormalities are apparent on either US or DMSA scan or both.

What do the latest guidelines tell us about UTIs in children under 2 years of age

The American Academy of Pediatrics (AAP) recently published new guidelines on diagnosing and managing infants and children younger than 2 years who have had a febrile urinary tract infection (UTI). They recommend, as previously did the National Institute for Health and Clinical Excellence (NICE) in the UK, a marked reduction in the imaging that these children should undergo. Both NICE and AAP agree that prophylactic antibiotic treatment should not be routinely used in these children, even in those with major vesicoureteric reflux.

Common childhood bacterial infections

Children with infectious diseases are commonly encountered in primary care settings. Identification of the subset of patients with bacterial infections is key in guiding the best possible management. Clinicians frequently care for children with infections of the upper respiratory tract, including acute otitis media, otitis externa, sinusitis, and pharyngitis. Conjunctivitis is not an uncommon reason for office visits. Bacterial pneumonia, urinary tract infections, and gastroenteritis are regularly seen. Over the last decade, a growing number of children have had infections of the skin and soft tissue, driven by the increased prevalence of infections caused by methicillin-resistant Staphylococcus aureus. The following review addresses the epidemiology and risk factors for specific infections and examines the clinical presentation and selection of appropriate diagnostic methods in such conditions. Methods to prevent these bacterial infections and recommendations for follow-up are suggested. Management of these infections requires that antimicrobial agents be used in a judicious manner in the outpatient setting. Such antibiotic therapy is recommended using both available clinical evidence and review of disease-specific treatment guidelines.

Pediatric urinary tract infections

Urinary tract infections (UTIs) in children are commonly seen in the emergency department and pose several challenges to establishing the proper diagnosis and determining management. This article reviews pediatric UTI and addresses epidemiology, diagnosis, treatment, and imaging, and their importance to the practicing emergency medicine provider. Accurate and timely diagnosis of pediatric UTI can prevent short-term complications, such as severe pyelonephritis or sepsis, and long-term sequelae including scarring of the kidneys, hypertension, and ultimately chronic renal insufficiency and need for transplant.

Vesicoureteral reflux in children with suspected and proven urinary tract infection

The aim of this study was to estimate the prevalence of vesicoureteral reflux (VUR) and clinically significant ultrasonography (US) abnormalities in a large group of children with proven and suspected urinary tract infection (UTI). The medical reports on renal US and voiding cystouretrographies (VCUG) of 2,036 children were reviewed. Renal US was performed on all children and VCUG on 1,185 children (58%). Based on the urine culture data, the UTI diagnoses were classified into five reliability classes (proven, likely, unlikely, false and no microbial data). The UTI diagnose was considered proven in 583/2036 (28.6%) and false in 145 (7.1%) cases. The prevalence of VUR was similar among those with proven and false UTI [37.4 vs. 34.8%; relative risk (RR) 1.08, 95% confidence intervals (95% CI) 0.7-1.7, P = 0.75] and decreased with increasing age (P = 0.001). Clinically significant US abnormalities occurred in 87/583 (14.9%) cases with proven UTI and significantly less often (11/145, 7.6%) in the false UTI class (RR 1.96, 95% CI 1.1-3.6, P = 0.02). Our finding supports the claim that VUR is not significantly associated to UTI and that its occurrence among children even without UTI is significantly higher than traditional estimates. This challenges the recommendations of routine VCUG after UTI.

Voiding urosonography with US contrast agent for the diagnosis of vesicoureteric reflux in children: an update

Voiding urosonography (VUS) entails the intravesical administration of US contrast agent (USCA) for the diagnosis of vesicoureteric reflux (VUR). VUS is now recognized as a practical, safe, radiation-free modality with comparable or higher sensitivity than direct radionuclide cystography (DRNC) and voiding cystourethrography (VCUG), respectively. An extensive review of the literature regarding both the procedural aspects and comparative diagnostic values of VUS has been published (Darge Pediatr Radiol 38:40-63, 2008a, b). The aim of this review is to provide an update on various facets of VUS that have taken place since the publication of the above-mentioned two reviews.

Screening young children with a first febrile urinary tract infection for high-grade vesicoureteral reflux with renal ultrasound scanning and technetium-99m-labeled dimercaptosuccinic acid scanning

OBJECTIVE

To evaluate the predictive value of renal ultrasound scanning and 99m-Technetium-dimercaptosuccinic acid (DMSA) scintigraphy for high-grade vesicoureteral reflux (VUR) in young children with a first urinary tract infection (UTI).

STUDY DESIGN

The medical records of children who had been examined with renal ultrasound scanning, DMSA scanning, and voiding cystourethrography (VCUG) were reviewed. The findings of renal ultrasound scanning, DMSA scanning, and their predictive values were evaluated.

RESULTS

Of 699 children, high-grade VUR (grades III-V) was diagnosed in 119 (17.0%). Signs of renal hypodysplasia (OR, 16.15), cyclic dilatation of pelvicaliceal system (OR, 11.73), hydroureter (OR, 4.00) with renal ultrasound scanning, and renal hypodysplasia (OR, 8.78), acute pyelonephritis (OR, 2.76) with DMSA scanning were associated with high-grade VUR. The sensitivities for high-grade VUR of ultrasound scanning alone (67.2%) or DMSA scanning alone (65.5%) were not as good as that of a both-test strategy, which had a sensitivity rate of 83.2%. The negative predictive value of the both-test strategy was 91.5%.

CONCLUSION

Renal ultrasound scanning and DMSA scanning both should be routinely performed in children with a first febrile UTI. VCUG is only indicated when abnormalities are apparent on either ultrasound scanning or DMSA scanning or both.

Management of childhood urinary tract infections: an economic modeling study

Childhood urinary tract infections (UTIs) can lead to renal scarring and ultimately to terminal renal failure, which has a high impact on quality of life, survival, and health-care costs. Variation in the treatment of UTIs between practices is high.

OBJECTIVE

To assess the cost-effectiveness of a maximum care model for UTIs in children, implying more testing and antibiotic treatment, compared with current practice in primary care in The Netherlands.

METHODS

We performed a probabilistic modeling study using Markov models. Figures used in the model were derived from a systematic review of the research literature. Multidimensional Monte Carlo simulation was used for the probabilistic analyses.

RESULTS

Maximum care gained 0.00102 (males) and 0.00219 (girls) QALYs (quality-adjusted life-years) and saved 42.70 euro (boys) and 77.81 euro (girls) in 30 years compared with current care, and was thus dominant. Net monetary benefit of maximum care ranged from 20 euro to 200 euro for a willingness to pay for a QALY ranging from 0 euro to 80,000 euro, respectively. Maximum care was also dominant over improved current care, although less dominant than to current care.

CONCLUSIONS

This study suggested that maximum care for childhood UTI was dominant in the long run to current care, meaning that it delivered more quality of life at lower costs. Nevertheless, making firm conclusions is not possible, given the limitations of the input data.

Vesicoureteric reflux is not a benign condition

Renal parenchymal defects may be congenital, usually associated with dilated vesicoureteric reflux (VUR), or they may appear in previously normal kidneys and be caused by reflux nephropathy due to VUR combined with urinary tract infection (UTI). A piglet model defined that the 70% of children with VUR and vulnerable pyramids would scar rapidly with their first UTI. Because most defects are present at first imaging after a UTI, and from the lack of benefit from apparently reasonable clinical interventions, many now believe that most defects are congenital, their association with VUR being a shared dysplasia rather than causal. Consequently, guidelines now argue for less assiduous management. These conclusions ignore adult human transplant evidence, adult pig studies, and clinical anecdotes, which indicate that scars may develop in infant kidneys quicker than urine culture can confirm the diagnosis, and that reflux nephropathy has no age limit. Its rarity over 4 years suggests that most vulnerable children develop scars before then, despite all medical efforts. I argue that preventing such scarring will require better diagnosis of infant UTI, quicker treatment, reliable imaging of scars and VUR, and subsequent protection until VUR resolves. To make a difference, we need more assiduous management, not less, and cannot afford to consider VUR to be a benign condition.

[Imaging studies in the first urinary infection with fever in infants: is voiding cystourethrography necessary?]

INTRODUCTION

The presence of vesicoureteral reflux (VUR) in an infant with urinary tract infection (UTI), does not necessarily lead to an acquired renal injury. Only serious reflux can be a factor in fostering its appearance.

OBJECTIVES

To assess whether in infants diagnosed for the first time with a UTI with a fever, a routine initial DMSA can be used as a screening method for detecting severe reflux and replace voiding cystourethrography (VCUG).

PATIENTS AND METHODS

We retrospectively studied 162 infants under 2 years old admitted to our hospital due to having a ITU with fever for the first time (92 males and 70 females). In all cases, a renal ultrasound, DMSA and VCUG had been performed a few days after the diagnosis.

RESULTS

Of the 162 patients, 62 (38 %) had VUR, of which 56 (90 %) were mild and 6 (10 %) were severe. The DMSA was abnormal in 26/100 patients without VUR (26 %), 12/56 with mild VUR (21 %) and 6/6 of those with severe VUR (100 %). DMSA sensitivity for detecting severe reflux was 100 % and specificity was 76 %. The positive predictive value and negative predictive value was 14 % and 100 % respectively. The positive likelihood ratio was 4.17 and the negative likelihood ratio was 0.

CONCLUSIONS

It is unnecessary to carry out VCUG in an infant with an initial UTI, and a negative DMSA.