The "top-down" approach to the evaluation of children with febrile urinary tract infection

Evaluating the requirement of ultrasonography for children with their first urinary tract infection

BACKGROUND

Management of urinary tract infection (UTI) in children remains important. It may be the first sign for a possible underlying congenital abnormalities for the kidney and urinary tract (CAKUT). This study examined whether performing renal and bladder ultrasonography (RBUS) only for children who have a pathogen other than E. coli during their first urinary tract infection (UTI), or who experience UTI recurrence, would result in more missed diagnoses of kidney anomalies.

METHODS

Patients aged between 2 months and 2 years who were seen in a tertiary pediatric hospital during a 2-year period and diagnosed with UTI were included. RBUS and voiding cystourethrography (VCUG) were performed according to American Academy of Pediatrics (AAP) guidelines. Afterwards, we looked back and evaluated how often we found kidney problems when we only did a RBUS on patients who had an atypical cause of their first UTI or who had multiple UTIs.

RESULTS

One hundred and seventy-eight patients who were followed up with UTI were included in this study. The isolated pathogen was E. coli in 104 cases (58.4 %) and atypical in 74 cases (41.6 %). VCUG was conducted on 40 patients, and vesicoureteral reflux (VUR) was discovered in 16 cases and ureteropelvic junction obstruction (UPJO) was discovered in 1 case. A different diagnostic approach that required the presence of an atypical pathogen at the first UTI or a fUTI recurrence to perform the RBUS would have missed just two severe kidney anomalies. It was observed that there could be a decrease of 40.4 % in RBUS and at least 20 % in VCUG.

CONCLUSIONS

A diagnostic approach that necessitates the presence of an abnormal pathogen during the initial UTI or a second UTI episode for the RBUS to be carried out would lead to fewer negative ultrasounds with minimal risk of overlooking kidney anomalies.

Piperacillin-Tazobactam versus Cefotaxime as Empiric Treatment for Febrile Urinary Tract Infection in Hospitalized Children

BACKGROUND

According to international pediatric urinary tract infection (UTI) guidelines, selecting ampicillin/sulbactam or amoxicillin/clavulanate is recommended as the first-line treatment for pediatric UTI. In Korea, elevated resistance to ampicillin and ampicillin/sulbactam has resulted in the widespread use of third-generation cephalosporins for treating pediatric UTIs. This study aims to compare the efficacy of piperacillin-tazobactam (TZP) and cefotaxime (CTX) as first-line treatments in hospitalized children with UTIs.

MATERIALS AND METHODS

The study, conducted at Jeju National University Hospital, retrospectively analyzed medical records of children hospitalized for febrile UTIs between 2014 and 2017. UTI diagnosis included unexplained fever, abnormal urinalysis, and the presence of significant uropathogens. Treatment responses, recurrence, and antimicrobial susceptibility were assessed.

RESULTS

Out of 323 patients, 220 met the inclusion criteria. Demographics and clinical characteristics were similar between TZP and CTX groups. For children aged ≥3 months, no significant differences were found in treatment responses and recurrence. Extended-spectrum beta-lactamase (ESBL)-positive strains were associated with recurrence in those <3 months.

CONCLUSION

In Korea, escalating resistance to empirical antibiotics has led to the adoption of broad-spectrum empirical treatment. TZP emerged as a viable alternative to CTX for hospitalized children aged ≥3 months with UTIs. Consideration of ESBL-positive strains and individualized approaches for those <3 months are crucial.

Predicting factors of clinically significant urological anomalies after initial urinary tract infection among 2- to 24-month-old children

AIM

To find more effective criteria to identify clinically significant urological anomalies after initial urinary tract infection among children.

METHODS

Children aged 2-24 months with an initial urinary tract infection were consecutively recruited in a Japanese hospital from 2013 to 2019. Voiding cystourethrography, 99mTc dimercaptosuccinic acid scan and ultrasound were intended to perform for all cases. Clinically significant urological anomalies were defined as high-grade vesicoureteral reflux, obstructive and abnormal urinary tract lesions, need for surgical intervention, renal hypoplasia and scarring. Using classification and regression tree analysis, we sought the associated factors. We developed new criteria with these factors, retrospectively applied them to the original data, and calculated the sensitivity and specificity.

RESULTS

One hundred sixty-seven patients were eligible, and 39 had clinically significant urological anomalies. Classification and regression tree analysis showed that the associated factors were non-E. coli infections, serum creatinine levels and ultrasound abnormalities. When the gold standards were performed on children with non-E. coli infections or serum creatinine levels ≥0.21 mg/dl, sensitivity and specificity were 0.82 and 0.68, respectively.

CONCLUSION

The criteria including non-E. coli infections and high-normal or higher serum creatinine levels may efficiently predict clinically significant urological anomalies after initial urinary tract infections.

SNMMI procedure standard/EANM practice guideline on pediatric [99mTc]Tc-DMSA renal cortical scintigraphy: an update

The Society of Nuclear Medicine and Molecular Imaging (SNMMI), founded in 1954, is an international scientific and professional organization with a purpose to promote the science, technology, and practical application of nuclear medicine. The European Association of Nuclear Medicine (EANM), founded in 1985, is a nonprofit professional medical association with a purpose to facilitate international communication among individuals in nuclear medicine pursuing clinical and academic excellence. Members of the SNMMI and EANM are physicians, technologists, and scientists who specialize in the research and practice of nuclear medicine. The SNMMI and EANM will periodically publish new guidelines for nuclear medicine practice to further advance the science of nuclear medicine and improve patient care. Existing standards/guidelines will be reviewed for revision or renewal, as appropriate. Each standard/guideline, representing a policy statement by the SNMMI/EANM, has undergone a thorough review, and represents an expert consensus. The SNMMI and EANM recognize that the safe and effective use of diagnostic nuclear medicine imaging requires specific training and skills, as described in each document. These standards/guidelines are educational resources designed to assist practitioners in providing appropriate nuclear medicine care for patients. They are consensus documents, and are not mandatory provisions or requirements of practice. They are not intended, nor should they be used, to establish a legal standard of care. For these reasons and those set forth below, the SNMMI and the EANM cautions against the use of these standards/guidelines in litigation procedures that call into question the clinical decisions of a practitioner. The ultimate judgment regarding the appropriateness and propriety of any specific procedure or course of action must be made by medical professionals, taking into account the unique context of each case. Thus, there is no implication that action differing from what is detailed in these standards/guidelines, on its own, is below the standard of care. On the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set forth in the standards/guidelines when, based on the reasonable judgment of the practitioner, such course of action is warranted based on the condition of the patient, limitations of available resources, or advances in knowledge or technology subsequent to publication of the standards/guidelines. Practicing medicine involves not only the science, but also the art of dealing with the prevention, detection, diagnosis, and treatment of disease. The variety and complexity of human conditions make it impossible for general guidelines to consistently allow for an accurate diagnosis to be reached or a specific treatment response to be predicted. Therefore, it should be recognized that adhering to these standards/guidelines does not ensure a successful outcome. All that should be expected is that a practitioner follows a reasonable course of action based on their level of training, the current landscape of knowledge, the resources at their disposal, and the needs/context of the particular patient being treated. The purpose of this document is to provide nuclear medicine physicians, radiologists, and other clinicians with guidelines for the recommendation, performance and interpretation of 99mTc-dimercaptosuccinic acid renal cortical scintigraphy ([99mTc] Tc-DMSA scintigraphy) in pediatric patients. These recommendations represent the expert opinions of experienced leaders in this field, and these recommendations are not all supported by a high level of evidence. Further studies are required to have evidence-based recommendations for the application of [99mTc] Tc-DMSA renal cortical scintigraphy in pediatrics. This guideline summarizes the views of the SNMMI Renal Cortical Scintigraphy in Children Working Group and the EANM Pediatrics Committee. It reflects recommendations for which the SNMMI and EANM cannot be held responsible. The recommendations should be taken into context of good practice of nuclear medicine and do not substitute for national and international legal or regulatory provisions.

Urinary tract infections in children

Urinary tract infections (UTIs) in children are among the most common bacterial infections in childhood. They are equally common in boys and girls during the first year of life and become more common in girls after the first year of life. Dividing UTIs into three categories; febrile upper UTI (acute pyelonephritis), lower UTI (cystitis), and asymptomatic bacteriuria, is useful for numerous reasons, mainly because it helps to understand the pathophysiology of the infection. A single episode of febrile UTI is often caused by a virulent Escherichia coli strain, whereas recurrent infections and asymptomatic bacteriuria commonly result from urinary tract malformations or bladder disturbances. Treatment of an upper UTI needs to be broad and last for 10 days, a lower UTI only needs to be treated for 3 days, often with a narrow-spectrum antibiotic, and asymptomatic bacteriuria is best left untreated. Investigations of atypical and recurrent episodes of febrile UTI should focus on urinary tract abnormalities, whereas in cases of cystitis and asymptomatic bacteriuria the focus should be on bladder function.

Accuracy of Ultrasound in Identifying Renal Scarring as Compared to DMSA Scan

OBJECTIVE

To assess the accuracy of renal ultrasound (RUS) in detecting renal scarring (RS).

METHODS

All initial DMSA scans performed from 2006 to 2009 for history of urinary tract infection (UTI) or vesicoureteral reflux (VUR) in patients under 14 years old were identified, and clinical history obtained via chart review. Patients who had RUS within 4 months of DMSA scan and no documented UTI during that interval were included. Decreased uptake of tracer associated with loss of contours or cortical thinning defined a positive DMSA study. Increased echogenicity/dysplasia, cortical thinning, atrophic kidney and/or abnormal corticomedullary differentiation defined a positive RUS. The sensitivity and specificity of RUS in identifying RS were calculated using DMSA scan as the gold standard.

RESULTS

A total of 144 patients had initial DMSA scans performed for UTI or VUR, with a RUS within 4 months, and no UTI between the 2 studies. Ninety-five of 144 (66%) had RS on DMSA and 49/144 (34%) did not. Patients with or without RS on DMSA were not different in gender (P = .073), age (P = .432), insurance (P = 1.000) or VUR grade (P = .132). Only 39/144 (27.1%) patients had positive RUS. The sensitivity of RUS for RS was 35.8% and the specificity was 89.8%, leading to an accuracy of 54.2% (95%CI; 45.7-62.5%, P = .999).

CONCLUSION

RUS demonstrated poor sensitivity for RS visualized on DMSA scan. This suggests that RUS is a poor screening test for RS or indicators of future renal scar. A normal ultrasound does not rule out RS or risk of future renal scar. Specificity of RUS was excellent.

Role of Late DMSA Renal Scan in Detecting High-Grade Vesicoureteral Reflux

OBJECTIVE

To determine the performance of late dimercaptosuccinic acid (DMSA) renal scans in identifying high-grade (III-V) vesicoureteral reflux (VUR) in children aged over 3 y with a febrile urinary tract infection (fUTI) history that has not been timely investigated.

METHODS

In this retrospective study of diagnostic accuracy, the clinical records of children aged between 3 and 18 y with fUTI history evaluated consecutively at Nephrology Unit of Hospital General de Niños Pedro de Elizalde, Argentina between 2006 and 2016 were reviewed. Patients with previously diagnosed renal or urinary tract abnormalities or who underwent previous postnatal genitourinary imaging were excluded. Only those assessed by renal and bladder ultrasound (RBUS), voiding cystourethrogram (VCUG) and late 6-mo DMSA scan were analyzed. The ability of the scintigraphy in identifying high-grade VUR was determined by comparing its findings with those of VCUG.

RESULTS

In 122 children (median age 5.37 y, 88.5% girls) RBUS was abnormal in 53 (43.4%) and 58 (47.5%) had VUR (30 of high-grade). Abnormal DMSA scan findings (70 patients, 57.4%) were associated with all grade (p = 0.00001) and with high-grade VUR (p = 0.00001). Sensitivity, specificity, negative (NPV) and positive (PPV) predictive values of late DMSA scans for all grades VUR were 93.1%, 75%, 92.3% and 77.1%, respectively. Only 4 patients with low-grade VUR had normal scans. For high-grade VUR, sensitivity and NPV reached 100%.

CONCLUSIONS

In older children, the normal late DMSA scan predicted the absence of high-grade VUR, obviating the need for a VCUG. This approach could be a possible strategy for children not studied at acute infection time.

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.

Contrast-enhanced voiding urosonography with intravesical administration of ultrasound contrast agent for the diagnosis of pediatric vesicoureteral reflux

Vesicoureteral reflux (VUR) is one of the most common urinary tract anomalies in children. It has been reported that VUR may be associated with reflux nephropathy. Ultrasound contrast-enhanced voiding urosonography (CeVUS) has become a routine diagnostic method for VUR in a number of European countries; however, it is not widely used in China. The aim of the present study was to analyze the clinical application and evaluate the safety of CeVUS as a diagnostic tool for VUR in children in order to establish a standardized operating procedure for CeVUS in pediatric VUR in China. Between August 2016 and October 2017, 90 children who were susceptible to VUR were admitted into the Pediatric Nephrology Department of Tongji Hospital and underwent CeVUS. The SonoVue second-generation USA contrast agent was administered intravesically via a transurethral bladder catheter at a dose of 1 ml. The occurrence of adverse events was monitored. Urine analysis and culture were performed. A total of 90 children (47 female, 43 male; mean age, 36.6 months) with 178 Pelvi-Ureteral Units (PUUs) underwent CeVUS to screen for VUR. VUR was detected in 44/90 pediatric patients (48.89%) and 65/178 PUUs (36.52%) by CeVUS. The grade distribution of the 65 PUUs with VUS was as follows: Grade I, 3; Grade II, 9; Grade III, 14; Grade IV, 22; and Grade V, 17. The accuracy of CeVUS in the present study were consistent with previous reports. No urethral anomalies were detected and there were no adverse events. CeVUS was demonstrated to be a safe, accurate and reliable imaging technique for detecting VUR in high-risk children, including neonates. Results of the present study indicated that CeVUS can be adopted as the primary screening and follow-up method for pediatric VUR diagnoses in China.

Clinical utility of FDG PET/CT in acute complicated pyelonephritis-results from an observational study

BACKGROUND

Acute complicated pyelonephritis (ACP) is an upper urinary tract infection associated with coexisting urinary tract abnormalities or medical conditions that could predispose to serious outcomes or treatment failures. Although CT and magnetic resonance imaging (MRI) are frequently used in patients with ACP, the clinical value of ¹⁸F-fluorodeoxyglucose positron emission tomography and computed tomography (FDG PET/CT) has not been systematically investigated. This single-center retrospective study was designed to evaluate the potential usefulness of FDG PET/CT in patients with ACP.

METHODS

Thirty-one adult patients with ACP who underwent FDG PET/CT were examined. FDG PET/CT imaging characteristics, including tracer uptake patterns, kidney volumes, and extrarenal imaging findings, were reviewed in combination with clinical data and conventional imaging results.

RESULTS

Of the 31 patients, 19 (61%) showed focal FDG uptake. The remaining 12 study participants showed a diffuse FDG uptake pattern. After volumetric approximation, the affected kidneys were found to be significantly enlarged. Patients who showed a focal uptake pattern had a higher frequency of abscess formation requiring drainage. ACP patients showing diffuse tracer uptake patterns had a more benign clinical course. Seven patients had suspected extrarenal coinfections, and FDG PET/CT successfully confirmed the clinical suspicion in five cases. FDG PET/CT was as sensitive as CT in identifying the six patients (19%) who developed abscesses. Notably, FDG PET/CT findings caused a modification to the initial antibiotic regimen in nine patients (29%).

CONCLUSIONS

FDG PET/CT may be clinically useful in the assessment of patients with ACP who have a progressive disease course.

Critical appraisal of the top-down approach for vesicoureteral reflux

Vesicoureteral reflux (VUR) has been linked to recurrent urinary tract infections (UTIs), renal scarring, hypertension, renal insufficiency and end-stage kidney disease. Different imaging strategies have been proposed to approach children presenting with UTI to sort out patients with significant VUR while minimizing patient morbidity, radiation exposure and financial burden. None of these imaging strategies is universally accepted. The“top-down approach” (TDA) aims at restricting the number of voiding cystourethrograms (VCUGs) and its associated morbidity while identifying patients with clinically-significant reflux. In this approach, children presenting with febrile UTIs are acutely investigated with dimercapto-succinic acid (DMSA) renal scans to identify patients with renal parenchymal inflammation. Those with evidence of renal affection are offered VCUG and late DMSA scan to identify VUR and permanent renal scarring, respectively. Although TDA could identify clinically-significant VUR with high sensitivity, it is not without limitations. The approach segregates patients based on the presence of DMSA cortical lesions omitting the morbidity and the economic burden of UTI. Additionally, some of DMSA lesions are attributed to congenital dysplasia and unrelated to UTI. Ionizing radiation exposure, financial costs, limited availability of DMSA scans in the acute setting, variability in interpreting the results and low yield of actionable findings on DMSA scans are some other limitations. In this review, we tried to address the drawbacks of the TDA and reinforce the value of patient-centered approach for VUR.

Imaging studies and biomarkers to detect clinically meaningful vesicoureteral reflux

The work-up of a febrile urinary tract infection is generally performed to detect vesicoureteral reflux (VUR) and its possible complications. The imaging modalities most commonly used for this purpose are renal-bladder ultrasound, voiding cystourethrogram and dimercapto-succinic acid scan. These studies each contribute valuable information, but carry individual benefits and limitations that may impact their efficacy. Biochemical markers are not commonly used in pediatric urology to diagnose or differentiate high-risk disease, but this is the emerging frontier, which will hopefully change our approach to VUR in the future. As it becomes more apparent that there is tremendous clinical variation within grades of VUR, the need to distinguish clinically significant from insignificant disease grows. The unfortunate truth about VUR is that recommendations for treatment may be inconsistent. Nuances in clinical decision-making will always exist, but opinions for medical versus surgical intervention should be more standardized, based on risk of injury to the kidney.

The diagnosis, evaluation and treatment of acute and recurrent pediatric urinary tract infections

Urinary tract infection (UTI) is one of the most common bacterial infections encountered by pediatricians. Currently, the diagnosis and management of acute UTI and recurrent UTI in children remain controversial. Recently published guidelines and large clinical trials have attempted to clarify UTI diagnostic and management strategies. In this manuscript, we review the diagnosis and management of acute and recurrent UTI in the pediatric population.

Antibiotic prophylaxis and reflux: critical review and assessment

The use of continuous antibiotic prophylaxis (CAP) was critical in the evolution of vesicoureteral reflux (VUR) from a condition in which surgery was the standard of treatment to its becoming a medically managed condition. The efficacy of antibiotic prophylaxis in the management of VUR has been challenged in recent years, and significant confusion exists as to its clinical value. This review summarizes the critical factors in the history, use, and investigation of antibiotic prophylaxis in VUR. This review provides suggestions for assessing the potential clinical utility of prophylaxis.

Does routine ultrasound change management in the follow-up of patients with vesicoureteral reflux?

INTRODUCTION

Children with vesicoureteral reflux (VUR) usually need a renal ultrasound (RUS). There is little data on the role of follow-up RUS in VUR. We evaluated the impact of follow-up RUS on the change in clinical management in patients with VUR.

METHODS

We prospectively analyzed children with a previous diagnosis of VUR seen in the outpatient clinic with a routine follow-up RUS within 4 months. Variables collected included: demographic data, VUR history, dysfunctional voiding symptoms and concurrent ultrasound findings. Change in management was defined as addition of new medication, nurse counselling, surgery or further investigations.

RESULTS

The study included 114 consecutive patients. The mean patient age was 4.5 years old, mean age of VUR diagnosis was 1.7 years, with average follow-up of 2.8 years. A change in management with stable RUS occurred in 14 patients, in which the change included ordering a DMSA in 9, nurse counselling for dysfunctional voiding in 3, and booking surgery in 2 patients. Change on RUS was seen in 4 patients. Multivariable analysis showed that history of urinary tract infection (UTI) since the last follow-up visit was more significant than RUS findings.

CONCLUSIONS

The RUS findings in most patients followed for VUR remain stable or with minimal changes. The variable showing a significant effect on change in management in our study was history of UTI since the last follow-up visit rather than RUS findings. The value of follow-up RUS for children with VUR may need to be revisited.

Patient and family impact of pediatric genitourinary diagnostic imaging tests

PURPOSE

The impact of diagnostic genitourinary imaging on patients and families is poorly understood. We measured patient and family reaction to commonly performed genitourinary imaging studies using a standardized measurement tool.

MATERIALS AND METHODS

We surveyed families undergoing genitourinary imaging (renal ultrasound, voiding cystourethrography, radionuclide cystogram, static renal scintigraphy and diuretic renal scintigraphy) using a Likert scaled 11-item survey to assess impact across 4 domains (pain, anxiety, time, satisfaction). Survey scores were analyzed using ANOVA and linear regression.

RESULTS

A total of 263 families were surveyed (61 renal ultrasound, 52 voiding cystourethrogram, 55 radionuclide cystogram, 47 mercaptoacetyltriglycine dynamic renal scintigraphy, 48 dimercaptosuccinic acid static renal scintigraphy). Mean patient age was 2.1 years old. Of the patients 45% were male and 77% were white. Patient age, gender and prior genitourinary imaging experience varied by study type. Study type was significantly associated with total and weighted scores on the genitourinary imaging survey (both p <0.0001). Renal ultrasound was scored as better and mercaptoacetyltriglycine dynamic renal scintigraphy was worse than voiding cystourethrogram, radionuclide cystogram and dimercaptosuccinic acid static renal scintigraphy, which did not differ from each other. Other factors associated with worse total scores included patient age 1 to 3 years (p <0.001) and nonwhite race (p = 0.04). Gender, prior testing history, wait time and parent education were not associated with total scores. In the multivariate model renal ultrasound remained the best and mercaptoacetyltriglycine dynamic renal scintigraphy the worst (p <0.0001). In a direct comparison dimercaptosuccinic acid static renal scintigraphy and voiding cystourethrogram total scores did not differ (p = 0.59).

CONCLUSIONS

There were significant differences among genitourinary imaging studies regarding the patient/family experience, but there was no overall difference between dimercaptosuccinic acid static renal scintigraphy and voiding cystourethrogram. These findings may be useful to aid decision making when considering genitourinary imaging for children.

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.

Economic and radiation costs of initial imaging approaches after a child's first febrile urinary tract infection

BACKGROUND. The traditional initial imaging approach following pediatric urinary tract infection is the "bottom-up" approach (cystogram and renal ultrasound). Recently, the "top-down" approach (nuclear renal scan followed by cystogram for abnormal scans only) has gained increasing attention. The relative cost and radiation doses of these are unknown METHODS. The authors used a decision model to evaluate these imaging approaches. Cost and effective radiation dose estimates, including sensitivity analyses, were based on one-time imaging only. RESULTS. Comparing hypothetical cohorts of 100 000 children, the top-down imaging approach cost $82.9 million versus $59.2 million for the bottom-up approach. Per-capita effective radiation dose was 0.72 mSv for top-down compared with 0.06 mSv for bottom-up. CONCLUSIONS. Routine use of nuclear renal scans in children following initial urinary tract infection diagnosis would result in increased imaging costs and radiation doses as compared to initial cystogram and ultrasound. Further data are required to clarify the long-term clinical implications of this increase.

Radiographic evaluation of children with febrile urinary tract infection: bottom-up, top-down, or none of the above?

The proper algorithm for the radiographic evaluation of children with febrile urinary tract infection (FUTI) is hotly debated. Three studies are commonly administered: renal-bladder ultrasound (RUS), voiding cystourethrogram (VCUG), and dimercapto-succinic acid (DMSA) scan. However, the order in which these tests are obtained depends on the methodology followed: bottom-up or top-down. Each strategy carries advantages and disadvantages, and some groups now advocate even less of a workup (none of the above) due to the current controversies about treatment when abnormalities are diagnosed. New technology is available and still under investigation, but it may help to clarify the interplay between vesicoureteral reflux, renal scarring, and dysfunctional elimination in the future.

Pediatric urologic conditions, including urinary infections

Genitourinary complaints are common in children, and the busy primary care provider must determine initial treatment and assess need for specialty referral. Many complaints are self-limited, but some represent disorders that can threaten organ function. In this article, an initial approach in the primary care office and a guide to specialty referral for pediatric urologic conditions of the urinary tract, male genitalia, and female genitalia are suggested.