Normal dimercaptosuccinic acid scintigraphy makes voiding cystourethrography unnecessary after urinary tract infection

Prediction model for severe vesicoureteral reflux in children with urinary tract infection and/or hydronephrosis

BACKGROUND

As voiding cystourethrography is invasive and exposes to radiation and urinary tract infection (UTI), identifying only high-grade reflux is important. We aimed to identify clinical, laboratory and imaging variables associated with high-grade primary reflux in children presenting with UTIs and/or urinary tract dilatation and develop a prediction model for severe reflux.

METHODS

Data of children who underwent voiding cystourethrography due to UTI and/or urinary tract dilatation were retrospectively analyzed for demographic, clinical and imaging findings. Patients with severe (grades 4-5) reflux were compared with the rest for these parameters and a prediction model was developed for severe reflux.

RESULTS

The study included 1044 patients (574 female). Severe reflux was present in 86 (8.2%) patients. Age < 2 years, male sex, non-E. coli uropathogens, UTD-P3 dilatation and multiple kidney scars on DMSA scintigraphy were associated with severe reflux. Using these variables a prediction model for severe reflux with a score ranging from 0-7 and accuracy rate of 93.4% was developed. A score ≥ 5 had sensitivity 44.2%, specificity 97.4%, PPV 60.3%, NPV 95.1% and OR 29.5 for severe reflux. Scores ≥ 5 and ≥ 4 catch 44% and 73% of severe reflux, while prevent invasive voiding cystourethrography in 94.0% and 83.6% of patients, respectively.

CONCLUSION

Age < 2 years, male sex, non-E. coli uropathogen growth, presence of UTD-P3 dilatation on ultrasonography and multiple scars on DMSA scintigraphy are risk factors for severe reflux. A scoring system based on these variables appears to be effective in predicting the presence of severe reflux and eliminating unnecessary voiding cystourethrography.

Adherence to the Swedish paediatric guidelines for urinary tract infections

AIM

To audit adherence to the Swedish paediatric guidelines for urinary tract infections (UTIs) in infants. Secondary objectives were to compare findings on imaging performed according to the guidelines with imaging without guideline support and to identify predictors of non-adherence.

METHODS

A prospective multicentre study of infants <1 year treated at paediatric hospitals for their first UTI. Adherence to recommendations was assessed for diagnosis, treatment, and imaging of the urinary tract with a follow-up period of 1 year. Vesicoureteral reflux on voiding cystourethrography and findings on renal scintigraphy according to recommendations were compared to imaging without recommendation.

RESULTS

A total of 1357 infants were included. Adherence to recommended diagnostic procedures, antibiotic treatment, and imaging was 86.1%, 91.0% and 64.2%, respectively. Non-adherence to imaging recommendations was associated with inpatient management and smaller hospitals but was also more often due to excessive rather than refrained imaging.

CONCLUSION

High adherence rates to diagnostic and treatment recommendations indicate careful attention to infant UTI among paediatricians. Lower adherence to imaging recommendations raises concerns regarding the guideline algorithm; particularly, early DMSA scans seem to be challenging for smaller hospitals.

Sonographic temporary nephromegaly in children during their first febrile urinary tract infection is a significant prognostic factor for recurrent infection

There are currently no available data on the relationship between sonographic temporary nephromegaly in children during their first febrile urinary tract infection (fUTI) and recurrent fUTI. For this analysis, a multicenter retrospective cohort study of 343 children who underwent renal ultrasound during their first fUTI was conducted between 2013 and 2020. Sonographic temporary nephromegaly was defined as increased renal length during the initial fUTI, followed by normal renal length after antibiotic treatment. Compared with children without sonographic temporary nephromegaly (n = 307), the duration of fever and intravenous antibiotics was significantly longer, and C-reactive protein, creatinine, and the proportion of children who had recurrent fUTI were significantly higher, in those with sonographic temporary nephromegaly (n = 36). In an additional analysis of 100 patients who received voiding cystourethrography, a logistic regression model confirmed that the odds of vesicoureteral reflux (VUR) were significantly higher in children with temporary nephromegaly or those who experienced fUTI recurrence. In nine out of 16 children with VUR who had temporary nephromegaly, the reason for receiving voiding cystourethrography was recurrent fUTI. Our results suggest that sonographic temporary nephromegaly during an initial fUTI is predictive for recurrence and VUR, and that in children with temporary nephromegaly, VUR may be detectable before fUTI recurrence.

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

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

Update and Summary of the European Association of Urology/European Society of Paediatric Urology Paediatric Guidelines on Vesicoureteral Reflux in Children

BACKGROUND AND OBJECTIVE

The prescriptive literature on vesicoureteral reflux (VUR) is still limited and thus the level of evidence is generally low. The aim of these guidelines is to provide a practical approach to the treatment of VUR that is based on risk analysis and selective indications for both diagnostic tests and interventions. We provide a 2023 update on the chapter on VUR in children from the European Association of Urology (EAU) and European Society for Paediatric Urology (ESPU) guidelines.

METHODS

A structured literature review was performed for all relevant publications published from the last update up to March 2022.

KEY FINDINGS AND LIMITATIONS

The most important updates are as follows. Bladder and bowel dysfunction (BBD) is common in toilet-trained children presenting with urinary tract infection (UTI) with or without primary VUR and increases the risk of febrile UTI and focal uptake defects on a radionuclide scan. Continuous antibiotic prophylaxis (CAP) may not be required in every VUR patient. Although the literature does not provide any reliable information on CAP duration in VUR patients, a practical approach would be to consider CAP until there is no further BBD. Recommendations for children with febrile UTI and high-grade VUR include initial medical treatment, with surgical care reserved for CAP noncompliance, breakthrough febrile UTIs despite CAP, and symptomatic VUR that persists during long-term follow-up. Comparison of laparoscopic extravesical versus transvesicoscopic ureteral reimplantation demonstrated that both are good option in terms of resolution and complication rates. Extravesical surgery is the most common approach used for robotic reimplantation, with a wide range of variations and success rates.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This summary of the updated 2023 EAU/ESPU guidelines provides practical considerations for the management and diagnostic evaluation of VUR in children.

ADVANCING PRACTICE

For children with VUR, it is important to treat BBD if present. A practical approach regarding the duration of CAP is to consider administration until BBD resolution.

PATIENT SUMMARY

We provide a summary and update of guidelines on the diagnosis and management of urinary reflux (where urine flows back up through the urinary tract) in children. Treatment of bladder and bowel dysfunction is critical, as this is common in toilet-trained children presenting with urinary tract infection.

Determining the effectiveness of the immature granulocyte percentage and systemic immune-inflammation index in predicting acute pyelonephritis

AIM

The most serious form of urinary tract infection (UTI) is acute pyelonephritis (APN), which can result in bacteremia and renal scarring. This study aims to show the roles that the systemic immune-inflammation index (SII) and the immature granulocyte (IG) percentage play in predicting APN in pediatric patients by comparing them with traditional infection markers. By illustrating a significant relationship between APN, the IG percentage, and the SII, the study's contributions to the differential diagnosis of UTI can promote a rapid and appropriate treatment of APN.

MATERIAL AND METHODS

The present study included 522 pediatric patients. The patients were divided into two groups: (I) an APN group (n = 236) and (II) a lower UTI group (n = 286).

RESULTS

The mean age of the sample was 5.05 ± 4.7 years. According to the most appropriate cutoff values, the findings showed that among all the parameters, C-reactive protein (CRP) and the IG percentage had the highest sensitivities, specificities, and predictive values for predicting APN.

CONCLUSION

This study emphasizes the support features of the IG percentage and the SII in the diagnosis of APN in pediatric patients, a topic that has recently attracted attention. The findings indicated that among all of the parameters behind CRP, the IG percentage and the SII had the highest sensitivities, specificities, and predictive values for forecasting APN. It is worth noting that these methods can be applied without additional costs or burdens to the patient.

A new recommendation for febrile urinary tract infection in children aged 2-24 months: Tepecik UTI Guideline-2

AIM

Urinary tract infections (UTIs) represent a common febrile illness in infancy. The study compared two UTI guidelines in terms of number of imaging studies, presence of parenchymal damage and radiation exposure in patients with the first febrile UTI between 2 and 24 months of age.

METHOD

The results of Tepecik UTI Guideline-1 used until 2012 (Group 1, n = 105) were retrospectively compared with Tepecik UTI Guideline-2 (Group 2) used after 2013. In Group 1, urinary tract ultrasonography (US), dimercaptosuccinic acid (DMSA) and voiding cystourethrography (VCUG) were made in all patients. In Group 2, if the US result was abnormal, patients were evaluated with VCUG and DMSA. If the US was normal, only DMSA was performed. If the DMSA was abnormal, the VCUG was undergone (n: 43, 40.9%).

RESULTS

The abnormal VCUG detection rate was 69.2% in Group 1 and 30.8% in Group 2 (p = 0.09). Sensitivity and specificity of US in the diagnosis of vesicoureteral reflux (VUR) was 15.9% and 96.7% in Group 1 and 61.5% and 70.5% in Group 2, respectively. Abnormal DMSA findings were observed among 33.3% (Groups 1) and 66.7% (Groups 2) subjects, respectively (p > 0.05). The median radiation exposure (500 mrem) of patients in Group 1 was statistically significantly higher than those in Group 2 (200 mrem) (p < 0.001).

CONCLUSION

The VCUG should not be the first examination to be considered in such patients. We think that Tepecik UTI Guideline-2 reduces unnecessary invasive procedure and radiation exposure and not missed VUR in the management of children with UTI at 2-24 months. Needs prospective follow-up studies before considering this recommendation.

Urinary Tract Infection in Children

Symptoms of urinary tract infection (UTI) in young children are nonspecific and urine sampling is challenging. A safe and rapid diagnosis of UTI can be achieved with new biomarkers and culture of clean-catch urine, reserving catheterization or suprapubic aspiration for severely ill infants. Most guidelines recommend ultrasound assessment and use of risk factors to direct further management of children at risk of kidney deterioration. The increasing knowledge of the innate immune system will add new predictors and treatment strategies to the management of UTI in children. Long-term outcome is good for the majority, but individuals with severe scarring can develop hypertension and decline in kidney function.

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.

Pediatric Nephro-Urology: Overview and Updates in Diuretic Renal Scans and Renal Cortical Scintigraphy

Nuclear medicine offers several diagnostic scans for the evaluation of congenital and acquired conditions of the kidneys and urinary track in children. Tc-99m-MAG 3 diuretic renal scans are most commonly used in the evaluation and follow up of urinary track dilatations. They provide functional information on the differential renal function and on drainage quality which is allows distinction between obstructed and non-obstructed kidneys and the need for surgical correction vs conservative management in kidneys with impaired drainage. Standardized imaging and processing protocols are essential for correct interpretation and for meaningful comparisons between follow up scans. Different approaches and conceptions led to some contradicting recommendations between SNMMI and EANM guidelines on diuretic renography in children which caused confusion and to the emergence of self-made institutional protocols. In Late 2018 the two societies published joint procedural guidelines on diuretic renography in infants and children which hopefully will end the confusion. Tc-99m DMSA scans provide important information about the function of the renal cortex allowing detection of acute pyelonephritis, renal scars dysplasia and ectopy as well as accurate determination of the differential renal function. They are commonly used in the evaluation of children with urinary tract infections and affect clinical management. A standardized imaging and processing protocol improves the diagnostic accuracy of these studies. SPECT or pinhole images should be a routine part of the imaging protocol. This is one of the recommendations in the new EANM and SNMMI procedural guidelines for renal cortical scintigraphy in children available online on the SNMMI website and is under publication. This article provides an overview on the clinical role of diuretic renography and cortical scintigraphy in children and describes the imaging protocols focusing on the new recommendations in the procedural guidelines.

How Swedish guidelines on urinary tract infections in children compare to Canadian, American and European guidelines

Urinary tract infections (UTI) are common in children and the guidelines focus on preventing kidney damage. We compared the 2013 national Swedish guidelines on UTIs in children with the guidelines from America, Canada, UK, Spain, Italy and European urologists. This showed that urinalysis and urine cultures are endorsed by all the guidelines, but sampling techniques and bacteria levels differ. They all recommend initial oral treatment and renal ultrasound to detect major anomalies in infants. The Swedish guidelines are more liberal on antibiotic prophylaxis. CONCLUSION: Differences in diagnostic criteria, workup and accepted methods for urine sampling were noted and are discussed.

Brazilian consensus on vesicoureteral reflux-recommendations for clinical practice

Introduction

Vesicoureteral Reflux (VUR) is characterized by a retrograde flow of urine from the bladder into the ureters and kidneys. It is one of the most common urinary tract anomalies and the major cause of urinary tract infection (UTI) in the first years of life. If not properly diagnosed and treated can lead to recurrent UTI, renal scar and, in severe cases, to end stage renal disease. Despite recent advances in scientific and technological knowledge, evaluation and treatment of VUR is still controversial and there is still considerable heterogeneity in evaluation methods and therapeutic approaches. The aim of the present consensus is to give a practical orientation on how to evaluate and treat VUR.

Methods

The board of Pediatric Urology of the Brazilian Society of Urology joined a group of experts and reviewed all important issues on Vesicoureteral Reflux evaluation and treatment and elaborated a draft of the document. On November 2017 the panel met to review, discuss and write a consensus document.

Results and Discussion

Vesicoureteral Reflux is a common and challenging problem in children. Children presenting with Vesicoureteral Reflux require careful evaluation and treatment to avoid future urinary tract infections and kidney scars. The panel addressed recommendations on up to date choice of diagnosis evaluation and therapies.

Visible and Near-Infrared Multispectral Features in Conjunction with Artificial Neural Network and Partial Least Squares for Predicting Biochemical and Micro-Structural Features of Beef Muscles

The objective of this study was to determine the potential of multispectral imaging (MSI) data recorded in the visible and near infrared electromagnetic regions to predict the structural features of intramuscular connective tissue, the proportion of intramuscular fat (IMF), and some characteristic parameters of muscle fibers involved in beef sensory quality. In order to do this, samples from three muscles (Longissimus thoracis, Semimembranosus and Biceps femoris) of animals belonging to three breeds (Aberdeen Angus, Limousine, and Blonde d’Aquitaine) were used (120 samples). After the acquisition of images by MSI and segmentation of their morphological parameters, a back propagation artificial neural network (ANN) model coupled with partial least squares was applied to predict the muscular parameters cited above. The results presented a high accuracy and are promising (R² test > 0.90) for practical applications. For example, considering the prediction of IMF, the regression model giving the best ANN model exhibited R²P = 0.99 and RMSEP = 0.103 g × 100 g⁻¹ DM.

Semiquantitative analysis of power doppler ultrasonography versus Tc-99m DMSA scintigraphy in diagnostic and severity assessment of acute childhood pyelonephritis

BACKGROUND

This study aimed to compare the diagnostic and predictive value of power Doppler ultrasonography (PDU) with Tc-99m dimercaptosuccinic acid (DMSA) renal scintigraphy in pediatric acute pyelonephritis (APN) using a semiquantitative analysis system.

METHODS

A total of 92 children and infants (184 kidneys) were hospitalized with possible APN. All children were examined by PDU and DMSA scintigraphy within 72 hours of admission. An empiric 9-point semiquantitative analysis system was used to sort kidneys into four grades (grade 0-III). Patients with several episodes of APN and congenital structural anomalies were excluded.

RESULTS

Of 184 kidneys, we found 68 abnormal (grade I-III) and 116 normal (Grade 0) with DMSA scintigraphy, and 84 abnormal and 100 normal with PDU. In all, 23 kidneys were shown to be diseased by PDU but normal on DMSA scintigraphy while 7 kidneys showed the opposite trend. The sensitivity and specificity of PDU for diagnosing APN was 89.7% and 80.2%, respectively (P<0.05). In children older than 6 months, the sensitivity was higher (92%, P<0.05) than that in children younger than 6 months (87%, P<0.05). A moderate agreement (41%, P<0.05) on grade was found between the two methods.

CONCLUSIONS

With the help of a semiquantitative analysis system, PDU can obviate the use of DMSA scintigraphy in children older than 6 months for APN diagnosis.

Guidelines for the medical management of pediatric vesicoureteral reflux

Urinary tract infection is a bacterial infection that commonly occurs in children. Vesicoureteral reflux is a major underlying precursor condition of urinary tract infection, and an important disorder in the field of pediatric urology. Vesicoureteral reflux is sometimes diagnosed postnatally in infants with fetal hydronephrosis diagnosed antenatally. Opinions vary regarding the diagnosis and treatment of vesicoureteral reflux, and diagnostic procedures remain debatable. In terms of medical interventions, options include either follow‐up observation in the hope of possible spontaneous resolution of vesicoureteral reflux with growth/development or provision of continuous antibiotic prophylaxis based on patient characteristics (age, presence/absence of febrile urinary tract infection, lower urinary tract dysfunction and constipation). Furthermore, there are various surgical procedures with different indications and rationales. These guidelines, formulated and issued by the Japanese Society of Pediatric Urology to assist medical management of pediatric vesicoureteral reflux, cover the following: epidemiology, clinical practice algorithm for vesicoureteral reflux, syndromes (dysuria with vesicoureteral reflux, and bladder and rectal dysfunction with vesicoureteral reflux), diagnosis, treatment (medical and surgical), secondary vesicoureteral reflux, long‐term prognosis and reflux nephropathy. They also provide the definition of bladder and bowel dysfunction, previously unavailable despite their close association with vesicoureteral reflux, and show the usefulness of diagnostic tests, continuous antibiotic prophylaxis and surgical intervention using site markings.

In children with urinary tract infection reduced kidney length and vesicoureteric reflux predict abnormal DMSA scan

BACKGROUND

To evaluate sensitivity, specificity, and positive and negative predictive values (PPV and NPV, respectively) of renal ultrasonography (US) in predicting renal uptake defects or reduced renal function at Tc-99m dimercaptosuccinic acid (DMSA) scan (primary outcome). We also evaluated which factors could be associated with Tc-99m DMSA renal scan anomalies.

METHODS

We retrospectively included all the patients with vesico-ureteral reflux (VUR) undergoing the first Tc-99m DMSA renal scan within 3 months from the most recent renal US between 2016 and 2018.

RESULTS

Sensitivity, specificity, PPV, and NPV of US in predicting abnormal Tc-99m DMSA scan were 38.9%, 91.5%, 71.9%, and 72.9%, respectively. Different length between the kidneys, expressed as standard deviation score (SDS), showed an area under the receiver operating characteristic curve of 0.70 (95% CI, 0.60-0.80; p < 0.0001) when evaluated as predictor of abnormal Tc-99m DMSA scan. A different length between the two kidneys >1.11 SDS had 91.5% sensitivity and 57.6% specificity. At multivariate analysis, the factors with significantly increased odds ratio of abnormal Tc-99m DMSA scan were difference in length between two kidneys >1.11 SDS and dilated VUR.

CONCLUSIONS

The Tc-99m DMSA scan remains the gold standard to detect renal parenchymal anomalies. A different length between the kidneys >1.11 SDS and dilated VUR are predictors of abnormal Tc-99m DMSA renal scan.

Prevention of recurrent febrile urinary tract infection in infants: Ultrasonography-oriented approach is more practical than a top-down approach

BACKGROUND

We previously reported that the top-down approach (TDA) for infants with febrile urinary tract infections (fUTI) could prevent recurrent fUTI (r-fUTI) but produced a high number of false-positives on acute-phase ^99m Tc dimercaptosuccinic acid (DMSA) renal scintigraphy. Therefore we compared the ultrasonography-oriented approach (USOA) with TDA from the viewpoint of prevention of r-fUTI.

METHODS

The TDA was applied between July 2010 and February 2014 and the USOA was applied between March 2014 and April 2017 in infants with first fUTI. In the USOA group, voiding cystourethrography (VCUG) was performed in the case of abnormality on acute-phase renal bladder ultrasonography (RBUS) or on chronic- phase DMSA, which were performed in all cases. The frequency of r-fUTI was compared between the TDA group and USOA group retrospectively.

RESULTS

Seventy-four infants (52 male) and 79 infants (60 male) received TDA or USOA, respectively. No significant differences were found between the TDA and USOA groups in male : female ratio, age in months at initial onset of fUTI, observation period, or number of cases of r-fUTI (TDA group, n = 4; USOA group, n = 5). Seventy-four DMSA scintigraphy and 25 VCUG were carried out in the USOA group, and 111 DMSA scintigraphy and 34 VCUG in the TDA group.

CONCLUSIONS

Both USOA and TDA were valid for prevention of r-fUTI, but USOA was superior to TDA with regard to the reduced number of patients undergoing VCUG and DMSA.

Comparison of Tc-99m DMSA Renal Planar Scan and SPECT for Detection of Cortical Defects in Infants with Suspected Acute Pyelonephritis

OBJECTIVE

To compare the detection rate of Tc-99m dimercaptosuccinic acid (DMSA) renal single photon emission computerized tomography (SPECT) with that of planar scan for renal cortical defects in infants under one year of age with suspected acute pyelonephritis.

METHODS

Sixty infants under one year of age who exhibited fever and pyuria were prospectively included in this study. All infants underwent concurrent Tc-99m DMSA renal planar scan and SPECT. Detection rates for cortical defects and the numbers of cortical defects in both kidneys were compared between Tc-99m DMSA planar scan and SPECT. The cortical defects were classified as large and small; the rate of discordant results was compared between subgroups.

RESULTS

Negative findings by planar scan in 11 infants (11.3%) were modified to positive findings by SPECT. The detection rate of SPECT was significantly higher than that of planar scan (53.3% vs. 35.0%, p < 0.001). The numbers of cortical defects on SPECT were significantly higher than those on planar scan (0.85 ± 0.97 vs. 0.53 ± 0.83, p < 0.001). A significantly higher rate of discordant results between the planar scan and SPECT was observed for the small cortical defects compared to the large cortical defects (48.6% vs. 14.3%, p = 0.029).

CONCLUSIONS

Tc-99m DMSA renal SPECT showed a higher detection rate, compared with planar scan, for renal cortical defects in infants with suspected acute pyelonephritis. The study results suggest that, compared with planar scan, Tc-99m DMSA SPECT can detect small cortical defects with greater sensitivity.

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.

Managing vesicoureteral reflux in children: making sense of all the data

Current management of vesicoureteral reflux (VUR) in children is the result of a steady albeit controversial evolution of data and thinking related to the clinical impact of VUR and urinary tract infection (UTI) in children, the value of clinical screening, and the relative impact of testing and interventions for VUR. While controversy continues, there is consensus on the importance of bladder dysfunction on VUR outcomes, the likelihood of VUR resolution, and the fact that not all children with VUR require active treatment. Early efforts to define risk stratification hold the most promise to provide more patient-specific treatment of UTI and VUR in children.

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

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

Delayed diagnosis of primary vesicoureteral reflux in children with recurrent urinary tract infections: Diagnostic approach and renal outcomes

OBJECTIVE

In this study, we aimed to assess renal outcomes of delayed diagnosis of dilating primary vesicoureteral reflux (VUR) following recurrent febrile urinary tract infections (fUTIs) and its diagnostic imaging procedures.

MATERIAL AND METHODS

The medical records of patients who underwent ultrasonography (US), non- acute dimercaptosuccinic acid (Tc-99mDMSA) scintigraphy and voiding cystourethrography (VCUG), and who were older than 2 years at the time of VUR diagnosis were retrospectively reviewed.

RESULTS

A total of 32 children (female, n=27: 84.4%) with a mean age of 7.67±3.34 years at the time of diagnosis of VUR were included in the study. Grade III, IV, V VUR were found in 22%, 69%, and 9% of the patients, respectively. At the time of VUR diagnosis, abnormal US findings were detected in 75% of the cases. Tc-99mDMSA detected abnormalities in 83.9% (7 with a single scar, 7 with multiple lesions, 12 with reduced kidney function) of the patients. Estimated glomerular filtration rate of 3 patients with bilateral grade IV VUR was <75 mL/min/1.73 m². In 5 patients (16%), VUR could not be predicted by US+DMSA scintigraphy (Grade IV VUR in 3 and Grade III in 2 cases ). The sensitivity in predicting VUR was 75.00% (95% CI: 56.60-88.54) and 83.87% (95% CI: 66.27-94.55), respectively, for US alone and combined US+DMSA.

CONCLUSION

VCUG should be performed routinely in addition to US and non-acute DMSA in all children referred with recurrent fUTIs. Awareness of childhood UTI in public and healthcare personnels should be increased in order to refer these patients at a early stage to pediatric urology and nephrology units.

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.

Performance of fluorescence spectroscopy for beef meat authentication: Effect of excitation mode and discriminant algorithms

This study evaluated the performance of classical front face (FFFS) and synchronous (SFS) fluorescence spectroscopy combined with Partial Least Square Discriminant Analysis (PLSDA), Support Vector Machine associated with PLS (PLS-SVM) and Principal Components Analysis (PCA-SVM) to discriminate three beef muscles (Longissimus thoracis, Rectus abdominis and Semitendinosus). For the FFFS, 5 excitation wavelengths were investigated, while 6 offsets were studied for SFS. Globally, the results showed a good discrimination between muscles with Recall and Precision between 47.82 and 94.34% and Error ranging from 6.03 to 32.39%. For the FFFS, the PLS-SVM with the 382nm excitation wavelength gave the best discrimination results (Recall, Precision and Error of 94.34%, 89.53% and 6.03% respectively). For SFS, when performing discrimination of the three muscles, the 120nm offset gave the highest Recall and Precision (from 57.66% to 94.99%) and the lowest Error values (from 6.78 to 8.66%) whatever the algorithm (PLSDA, PLS-SVM and PCA-SVM).

Yield of Imaging Performed as per Indian Society of Pediatric Nephrology Guidelines in Children with Urinary Tract Infection

OBJECTIVE

To assess yield of imaging performed as per Indian Society of Pediatric Nephrology (ISPN) urinary tract infection (UTI) guideline.

METHODS

Ultrasonography (USG), voiding cystourethrography (VCUG) and dimercaptosuccinic-acid (DMSA) scintigraphy were performed in 183 children (age 0-5y) with first episode (age 0-1y) of UTI or recurrent (age <5y) UTI, as per ISPN recommendations.

RESULTS

Significant abnormalities were detected in 110 (63%), with vesicoureteric reflux (VUR) grades 3-5 in 31% and renal scars in 43%. Combined USG and DMSA had a negative predictive value of 94% for significant VUR.

Conclusion

ISPN guideline resulted in a high yield of detection of significant abnormalities.

Top-down approach is possible strategy for predicting breakthrough fUTIs and renal scars in infants

BACKGROUND

Acute-phase technetium-99 m dimercaptosuccinic acid (DMSA) scintigraphy is recommended for initial imaging in children with febrile urinary tract infection (fUTI). Recently, the importance of identifying patients at risk of recurrent fUTI (r-fUTI) has been emphasized. To clarify the effectiveness of DMSA scintigraphy for predicting r-fUTI in infants, we investigated the relationship between defects on DMSA scintigraphy and r-fUTI.

METHODS

Seventy-nine consecutive infants (male: female, 60:19) with fUTI were enrolled in this study. DMSA scintigraphy was performed in the acute phase, and patients with defect underwent voiding cystourethrography and chronic-phase (6 months later) DMSA scintigraphy. Patients were followed on continuous antibiotic prophylaxis (CAP).

RESULTS

Defects on acute-phase DMSA scintigraphy were observed in 32 children (40.5%) of 79. The mean follow-up observation period was 17.0 ± 10.1 months. Four patients had r-fUTI (5%). Two of them had defects on DMSA scintigraphy in both the acute phase and chronic phase, and had bilateral vesicoureteral reflux (VUR) grade IV. Two others had r-fUTI without defects on DMSA and did not have VUR. Twelve patients had defect on chronic-phase DMSA scintigraphy and four of them had no VUR.

CONCLUSIONS

The top-down approach is a possible method for predicting r-fUTI in infants and does not miss clinically significant VUR. Also, given that the prevalence of r-fUTI was 5% regardless of the presence of defects on acute-phase DMSA, then, in conjunction with genital hygiene and CAP, acute-phase DMSA might be unnecessary if chronic-phase DMSA is performed for all patients to detect renal scar.

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.

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.

Imaging of the Pediatric Urinary System

Recent advances in pediatric urinary tract imaging include development of alternative imaging methods without use of ionizing radiation; evolving understanding of the relationship of urinary tract infection, vesicoureteral reflux, and renal scarring, including the important role of dysfunctional voiding; development of a consensus nomenclature and risk-based classification for fetal and antenatal urinary tract dilation; advances in the understanding of sporadic and inherited renal cystic disease; and a proposed modification of the Bosniak criteria for distinguishing complex renal cysts from cystic renal tumors in children.

Micturating cystourethrogram as a tool for investigating UTI in children - An institutional audit

BACKGROUND

Micturating cystourethrograms (MCUG) are the gold standard for evaluating vesicoureteric reflux (VUR). There is a growing consensus for increasing the threshold for performing MCUGs following urinary tract infections (UTI) in children. There are several varying guidelines. It is important to detect high-grade reflux in the setting of an UTI because of potential long-term complications.

OBJECTIVE

This audit aimed to retrospectively: (1) identify the conformance rate of local guidelines at the Women's and Children's Hospital (WCH); (2) assess predictors for an abnormal MCUG; and (3) compare local guidelines against the Royal Children's Hospital, Melbourne (RCH), National Institute for Healthcare and Excellence (NICE), and American Academy of Pediatrics (AAP) guidelines for selectively detecting high-grade reflux.

METHOD

The number of MCUGs performed from 2008 to 2012 at the WCH radiology department was collected. Patients undergoing MCUG during the 2012 calendar year were identified. Only children having an initial MCUG as part of an UTI investigation with prerequisite imaging as per guidelines were included. Each child's age, sex, referral source, reason, renal ultrasound (RUS) prior to the MCUG, MCUG result and VUR grade were recorded. The WCH guidelines were applied to determine conformance, to evaluate predictors for an abnormal MCUG, and compared against other retrospectively applied guidelines (RCH, NICE, AAP).

RESULTS/DISCUSSION

There was complete data for 168 children who underwent MCUG as part of an UTI investigation (median age 0.79 years, range 0.12-8.74, male:female 67:101). There were 67/168 abnormal MCUGs (62 children with VUR, five bladder diverticulum), and 97 refluxing renal units (43 high-grade VUR units). No posterior urethral valves (PUV) were identified as part of the UTI investigation. A total of 143/168 patients had prior RUS (normal:abnormal 67:76). The WCH guidelines had 82% conformance. There was no statistically significant association between an abnormal MCUG and age, sex, referral source, reason, or prior RUS result. The WCH guidelines may have missed five children with high-grade VUR (four children had surgery), compared with RCH, APP and NICE, with 8, 15, and 17 children, respectively, having high-grade VUR (two, five, and five children had surgery, respectively) show in the Summary Table. The retrospective study had limitations and possible selection bias (children with UTI without a MCUG). There were no standard treatment approaches for VUR; hence establishing a MCUG guideline is difficult. An alternative is the top-down approach.

CONCLUSION

Current institutional guidelines for considering MCUG following UTI in children vary considerably. The MCUG guidelines at any institution must take into account the local management guidelines for high-grade VUR.

Acute health care utilization and outcomes for outpatient-treated urinary tract infections in children

INTRODUCTION

The majority of urinary tract infections (UTIs) in children are treated in the ambulatory setting. The goal of this study is to describe the course of outpatient UTI management, including health services utilization, antibiotic switching (change from empirically prescribed antibiotic to another antibiotic), and antibiotic side effects.

METHODS

Using a large claims database, Truven Health MarketScan Research Database, we analyzed all children younger than 18 years old who had an antibiotic prescribed for an outpatient UTI from 2002 to 2010. We evaluated health services utilization and antibiotic switching in the 21-day period after UTI diagnosis. We compared side effects with rates in patients receiving narrow versus broad-spectrum antibiotic treatment. Chi-square analysis was used for descriptive statistics.

RESULTS

We identified 242,819 outpatient, antibiotic-treated, UTI episodes. During the 21-day period after presentation, 26% required more than one visit for UTI management and <1% required hospital admission (Figure). Most children did not have imaging within 21 days of UTI: renal bladder ultrasound in 6%, VCUG in 2.6%, and DMSA in 0.05%. Broad-spectrum antibiotics were empirically prescribed to 34% of patients. Antibiotic switching occurred in only 8% of UTI episodes, indicating that empiric prescription covered the offending uropathogen the majority of the time. Antibiotic side effects occurred in 8% of UTI episodes. The most common side effects were gastrointestinal (∼3% of UTI episodes). All other side effects occurred in <1% of UTI episodes. Although there were statistically significant differences in side effects between broad- and narrow-spectrum antibiotics, these differences were not clinically relevant.

CONCLUSIONS

Most outpatient UTIs in children do not require more than one healthcare visit, hospital admission, or change in empiric antibiotic therapy. This study supports the fact that pediatric UTIs can be effectively treated in the ambulatory setting.

Acute pyelonephritis in children

Acute pyelonephritis is one of the most serious bacterial illnesses during childhood. Escherichia coli is responsible in most cases, however other organisms including Klebsiella, Enterococcus, Enterobacter, Proteus, and Pseudomonas species are being more frequently isolated. In infants, who are at major risk of complications such as sepsis and meningitis, symptoms are ambiguous and fever is not always useful in identifying those at high risk. A diagnosis of acute pyelonephritis is initially made on the basis of urinalysis; dipstick tests for nitrites and/or leukocyte esterase are the most accurate indicators of infection. Collecting a viable urine sample for urine culture using clean voided methods is feasible, even in young children. No gold standard antibiotic treatment exists. In children appearing well, oral therapy and outpatient care is possible. New guidelines suggest less aggressive imaging strategies after a first infection, reducing radiation exposure and costs. The efficacy of antibiotic prophylaxis in preventing recurrence is still a matter of debate and the risk of antibiotic resistance is a warning against its widespread use. Well-performed randomized controlled trials are required in order to better define both the imaging strategies and medical options aimed at preserving long-term renal function.

Dimercaptosuccinic acid scan or ultrasound in screening for vesicoureteral reflux among children with urinary tract infections

BACKGROUND

There is considerable interest in detecting vesicoureteral reflux (VUR) because its presence, especially when severe, has been linked to an increased risk of urinary tract infections and renal scarring. Voiding cystourethrography (VCUG), also known as micturating cystourethrography, is the gold standard for the diagnosis of VUR, and the grading of its severity. Because VCUG requires bladder catheterisation and exposes children to radiation, there has been a growing interest in other screening strategies that could identify at-risk children without the risks and discomfort associated with VCUG.

OBJECTIVES

The objective of this review is to evaluate the accuracy of two alternative imaging tests - the dimercaptosuccinic acid renal scan (DMSA) and renal-bladder ultrasound (RBUS) - in diagnosing VUR and high-grade VUR (Grade III-V VUR).

SEARCH METHODS

We searched MEDLINE, EMBASE, BIOSIS, and the Cochrane Register of Diagnostic Test Accuracy Studies from 1985 to 31 March 2016. The reference lists of relevant review articles were searched to identify additional studies not found through the electronic search.

SELECTION CRITERIA

We considered published cross-sectional or cohort studies that compared the results of the index tests (DMSA scan or RBUS) with the results of radiographic VCUG in children less than 19 years of age with a culture-confirmed urinary tract infection.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the selection criteria to all citations and independently abstracted data. We used the bivariate model to calculate summary sensitivity and specificity values.

MAIN RESULTS

A total of 42 studies met our inclusion criteria. Twenty studies reported data on the test performance of RBUS in detecting VUR; the summary sensitivity and specificity estimates were 0.44 (95% CI 0.34 to 0.54) and 0.78 (95% CI 0.68 to 0.86), respectively. A total of 11 studies reported data on the test performance of RBUS in detecting high-grade VUR; the summary sensitivity and specificity estimates were 0.59 (95% CI 0.45 to 0.72) and 0.79 (95% CI 0.65 to 0.87), respectively. A total of 19 studies reported data on the test performance of DMSA in detecting VUR; the summary sensitivity and specificity estimates were 0.75 (95% CI 0.67 to 0.81) and 0.48 (95% CI 0.38 to 0.57), respectively. A total of 10 studies reported data on the accuracy of DMSA in detecting high-grade VUR. The summary sensitivity and specificity estimates were 0.93 (95% CI 0.77 to 0.98) and 0.44 (95% CI 0.33 to 0.56), respectively.

AUTHORS' CONCLUSIONS

Neither the renal ultrasound nor the DMSA scan is accurate enough to detect VUR (of all grades). Although a child with a negative DMSA test has an < 1% probability of having high-grade VUR, performing a screening DMSA will result in a large number of children falsely labelled as being at risk for high-grade VUR. Accordingly, the usefulness of the DMSA as a screening test for high-grade VUR should be questioned.

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.

Vesicoureteral reflux and bladder dysfunction

The relationship between vesicoureteral reflux and bladder dysfunction is inseparable and has long been emphasized. However, the primary concern of all physicians treating patients with vesicoureteral reflux is the prevention of renal scarring and eventual deterioration of renal function.

Bladder dysfunction, urinary tract infection and vesicoureteral reflux are the three important factors which are closely related to each other and contribute to the formation of renal scar. Especially, there is ongoing discussion regarding the role of bladder dysfunction in the prognosis of both medically and surgically treated vesicoureteral reflux. The effect of bladder dysfunction on VUR is mostly via inadequate sphincter relaxation during infancy which is closer to immature bladder dyscoordination rather than true dysfunction. But after toilet training, functional obstruction caused by voluntary sphincter constriction during voiding is responsible through elevation in bladder pressure, thus distorting the architecture of bladder and ureterovesical junction. Reports suggest that voiding phase abnormalities in lower urinary tract dysfunction contributes to lower spontaneous resolution rate of VUR. However, filling phase abnormalities such as involuntary detrusor contraction can also cause VUR even in the absence of dysfunctional voiding. With regards to the effect of bladder dysfunction on treatment, meta-analysis reveals that the cure rate of VUR following endoscopic treatment is less in children with bladder bowel dysfunction but there is no difference for open surgery.

The pathophysiology of bladder dysfunction associated with UTI can be explained by the ‘milk-back’ of contaminated urine back into the bladder and significant residual urine resulting from functional outlet obstruction. In addition, involuntary detrusor contraction can decrease perfusion of the bladder mucosa thus decreasing mucosal immunity and creating a condition prone to UTI. In terms of renal scarring, dysfunctional voiding seems to be more closely related to renal damage in association with VUR than overactive bladder. However, studies show that UTI can induce renal scarring even without VUR present and urodynamic abnormalities are quite often detected in these cases. Whether reflux of sterile urine in bladder dysfunction can cause significant renal scarring, especially when intrarenal reflux is present remains controversial. Another issue that warrants further research is the direct relationship between bladder dysfunction and renal scarring, since some reports suggest that these two conditions share a common genotype.

Recently some studies have suggest VUR as a causal factor of bladder dysfunction, supported by the fact that bladder dysfunction resolves after injection therapy of VUR. Further study with more objective evaluation of bladder dysfunction may be needed.

Update on the approach of urinary tract infection in childhood

OBJECTIVE

Urinary tract infection (UTI) is the most common bacterial infection in childhood. UTI may be the sentinel event for underlying renal abnormality. There are still many controversies regarding proper management of UTI. In this review article, the authors discuss recent recommendations for the diagnosis, treatment, prophylaxis, and imaging of UTI in childhood based on evidence, and when this is lacking, based on expert consensus.

SOURCES

Data were obtained after a review of the literature and a search of Pubmed, Embase, Scopus, and Scielo.

SUMMARY OF THE FINDINGS

In the first year of life, UTIs are more common in boys (3.7%) than in girls (2%). Signs and symptoms of UTI are very nonspecific, especially in neonates and during childhood; in many cases, fever is the only symptom.

CONCLUSIONS

Clinical history and physical examination may suggest UTI, but confirmation should be made by urine culture, which must be performed before any antimicrobial agent is given. During childhood, the proper collection of urine is essential to avoid false-positive results. Prompt diagnosis and initiation of treatment is important to prevent long-term renal scarring. Febrile infants with UTIs should undergo renal and bladder ultrasonography. Intravenous antibacterial agents are recommended for neonates and young infants. The authors also advise exclusion of obstructive uropathies as soon as possible and later vesicoureteral reflux, if indicated. Prophylaxis should be considered for cases of high susceptibility to UTI and high risk of renal damage.

Predictive value of specific ultrasound findings when used as a screening test for abnormalities on VCUG

BACKGROUND

Renal and bladder ultrasound (RBUS) is often used as an initial screening test for children after urinary tract infection (UTI), and the 2011 AAP guidelines specifically recommend RBUS be performed first, with voiding cystourethrogram (VCUG) to be performed only if the ultrasound is abnormal. It is uncertain whether specific RBUS findings, alone or in combination, might make RBUS more useful as a predictor of VCUG abnormalities.

AIMS

To evaluate the association of specific RBUS with VCUG findings, and determine whether predictive models that accurately predict patients at high risk of VCUG abnormalities, based on RBUS findings, can be constructed.

METHODS

and study sample: A total of 3995 patients were identified with VCUG and RBUS performed on the same day. The RBUS and VCUG reports were reviewed and the findings were classified. Analysis was limited to patients aged 0-60 months with no prior postnatal genitourinary imaging and no history of prenatal hydronephrosis.

ANALYSIS

The associations between large numbers of specific RBUS findings with abnormalities seen on VCUG were investigated. Both multivariate logistic models and a neural network machine learning algorithms were constructed to evaluate the predictive power of RBUS for VCUG abnormalities (including VUR or bladder/urethral findings). Sensitivity, specificity, predictive values and area under receiving operating curves (AUROC) of RBUS for VCUG abnormalities were determined.

RESULTS

A total of 2259 patients with UTI as the indication for imaging were identified. The RBUS was reported as "normal" in 75.0%. On VCUG, any VUR was identified in 41.7%, VUR grade > II in 20.9%, and VUR grade > III in 2.8%. Many individual RBUS findings were significantly associated with VUR on VCUG. Despite these strong univariate associations, multivariate modeling didn't result in a predictive model that was highly accurate. Multivariate logistic regression built via stepwise selection had: AUROC = 0.57, sensitivity = 86% and specificity = 25% for any VUR; AUROC = 0.60, sensitivity = 5% and specificity = 99% for VUR grade > II; and AUROC = 0.67, sensitivity = 6% and specificity = 99% for VUR grade > III. The best predictive model constructed via neural networks had: AUROC = 0.69, sensitivity = 64% and specificity = 60% for any VUR; AUROC = 0.67, sensitivity = 18% and specificity = 98% for VUR grade > II; and AUROC = 0.79, sensitivity = 32% and specificity = 100% for VUR grade > III.

CONCLUSIONS

Even with the state-of-the-art predictive models, abnormal findings on RBUS provide a poor screening test for genitourinary abnormalities. Renal bladder ultrasound and VCUG should be considered complementary, as they provide important, but different, information.

Ultrasonography and C-reactive protein can predict the outcomes of voiding cystography after the first urinary tract infection

AIM

This study evaluated whether sex, clinical variables, laboratory variables or ultrasonography predicted the presence of vesicoureteric reflux during the first episode of urinary tract infection in paediatric patients. We also aimed to define the criteria that indicated the need for voiding cystography testing.

METHODS

We used voiding cystography to investigate 200 patients who experienced their first urinary tract infection at our institution between 2004 and 2013 and retrospectively analysed the data by reviewing their medical records.

RESULTS

Sex (p = 0.001), peak blood C-reactive protein levels (p < 0.001), the duration of fever after antibiotic administration (p = 0.007) and the ultrasonography findings grade (p < 0.001) were significantly different between patients with and without vesicoureteric reflux. Grade IV-V ultrasonography findings and C-reactive protein levels of ≥80 mg/L predicted vesicoureteric reflux with a sensitivity, specificity and odds ratio of 47.8%, 87.8% and 6.59 (95% confidence interval = 3.26-13.33), respectively (p < 0.001).

CONCLUSION

Voiding cystography should be performed for patients with C-reactive protein levels of ≥80 mg/L and grade IV-V ultrasonography findings, but is not necessary in patients with C-reactive protein levels of <80 mg/L and grade I-III ultrasonography findings.