Impact of contrast agents on organ dosimetry in pediatric diagnostic fluoroscopy: the voiding cystourethrogram.

Objective.International Commission on Radiological Protection (ICRP) Task Group 113 is developing reference values of organ and effective dose coefficients (DCs) for radiography, fluoroscopy, and computed tomography imaging exams. In support of these efforts, our focus is on pediatric diagnostic fluoroscopy. Contrast agents used during clinical examinations are an important consideration of the work undertaken by the Task Group. This work demonstrates the importance of including organ contrast volume concentrations for the calculation of reference organ DCs in the voiding cystourethrogram (VCUG).Approach.The ICRP newborn and 15 year female reference phantoms were utilized within the Particle and Heavy Ion Transport code system for the calculation of organ DCs. A pediatric radiologist with over 30 years of clinical experience defined the imaging fields for a VCUG examination consistent with clinical practice. Of these, four imaging fields were selected for investigation. The transport simulations modeled an iodinated contrast solution similar to Bracco Group's 18% weight per volume, cystografin diatrizoate meglumine and typical bladder content was supplemented to make up the remainder volume. Iodinated contrast volumes of 0%, 25%, 50%, 75%, and 100% concentration by volume were modeled and associated DCs for in-field organs were computed.Main results.Organ DCs were calculated for the urinary bladder wall, colon wall, ovaries, and uterus for both female phantoms under irradiation geometries representative of a VCUG examination. Some organ DCs increased with iodine volume in the bladder and other organ DCs decreased as the iodine contrast volume completely filled the bladder (100%).Significance.The study results demonstrate for the newborn phantom percent differences in organ DCs varied between 0%-10% for the organs of interest, while they varied between 0%-22% in the 15 year phantom suggesting the importance of including contrast media in Monte Carlo radiation transport simulations of the VCUG examination.

Vesico-ureteral reflux diagnosis after initial kidney abscess: Results from a Paediatric Tertiary Hospital.

AIMS: Guidelines regarding voiding cystourethrogram (VCUG) indications following a paediatric kidney abscess are lacking. This study evaluates vesicoureteral reflux (VUR) prevalence and outcome after a first kidney abscess. METHODS: This retrospective study included all children presenting to a tertiary paediatric reference centre with de-novo kidney abscesses from 2011 to 2022, diagnosed through imaging (ultrasonography or computed tomography). VCUG's clinical utility was assessed by exploring outcomes related to interventions. RESULTS: Among the 17 patients (median age 9 months, IQR; 6 months-6 years), VCUG identified VUR in 7 (41%; 95% CI: 18-65%), including two with grade IV-V. Median abscess size was 19 mm (IQR; 14-27). 7/8 (88%) children with DMSA scan presented scars, including 4 with hypofunctioning (20%-44%), and one with a non-functioning kidney. Scarring on the DMSA scan was similar regardless of identified VUR. Six children had subsequent pyelonephritis. Three of the remaining 11 had grade I-III and two IV-V VUR. Surgery was required in four children overall: three for recurrent pyelonephritis and one for high-grade VUR and scars. CONCLUSION: Among initial kidney abscess cases, 41% had VUR, similar to children experiencing their first uncomplicated pyelonephritis. VCUG results guided antibiotic prophylaxis but not surgical decisions. We suggest considering VCUG following recurrent pyelonephritis/kidney abscess and/or kidney scarring.

Surgical management of high-grade vesicoureteral reflux in an 18-month-old female with a solitary kidney: A case report from a resource-limited setting.

Key Clinical Message: Conservative nonsurgical therapy ensures that the resolution is nearly 80% for vesicoureteral reflux grades I and II and 30%-50% for vesicoureteral reflux grades III and V within 4-5 years of follow-up. Open surgical reimplantation of ureters of grades IV and V is a highly successful procedure, with reported correction rates ranging from 95% to 99% regardless of the severity of vesicoureteral reflux. Abstract: Patients with vesicoureteral reflux present with a wide range of severity. With an incidence of approximately 1%, vesicoureteral reflux is a relatively common urological abnormality in children. Postnatal diagnosis of vesicoureteral reflux is typically made following a diagnosis of a urinary tract infection and less frequently following family screening. Voiding cystourethrograms remain the gold standard for diagnosing vesicoureteral reflux. To preserve the kidney and prevent the need for potential renal replacement therapy, infants with a single kidney require significantly more assessments and prompt decision-making. Surgical correction is advised for patients with vesicoureteral reflux grades IV and V, while vesicoureteral reflux grades I, II, and III are managed conservatively.

The impact of the distal ureteral diameter ratio, bladder volume at onset of vesicoureteral reflux, and/or grade in predictive models of clinical outcomes in children with vesicoureteral reflux.

PURPOSE: Vesicoureteral reflux (VUR) grade has been used as a primary factor in assessing a child's risk of clinical outcomes. Unfortunately, grade has poor inter-observer reliability. We hypothesized that more objective and reliable VCUG parameters including the distal ureteral diameter ratio (UDR) and volume at onset of VUR (Vol) may either augment or replace the current grading system to provide more reliable prediction of clinical outcomes. MATERIALS AND METHODS: Multivariate clinical outcome models were analyzed to assess the impact on predictive accuracy by the addition of voiding cystourethrogram (VCUG) data including grade, UDR, and Vol, alone or in combinations. Clinical variables from retrospective review of 841 children's records included age, gender, presentation, VUR laterality, bowel and bladder dysfunction, history of febrile urinary tract infection (UTI), and number of UTIs. The primary outcomes assessed included VUR resolution or persistence and need for operative intervention. RESULTS: Grade, UDR, and Vol were independent predictors of resolution and operative intervention. Vol increased predictive accuracy in resolution models with grade or UDR alone; however, no significant difference occurred in models with the substitution of grade with UDR. CONCLUSIONS: A more reliable classification system for VUR, with improved predictive accuracy regarding clinical outcomes, may be developed incorporating UDR and Vol. Whether VUR grade can be completely replaced by Vol and UDR measurements requires further evaluation with larger number of patients.

Radiation exposure in pediatric videourodynamics: An evaluation of safety in comparison to voiding cystourethrogram.

INTRODUCTION: Children with spina bifida (SB) undergo a videourodynamic study (VUDS) or urodynamic study and voiding cystourethrogram (VCUG). A standardized protocol for imaging during a pediatric VUDS has not been established. Our aim is to quantify radiation exposure and establish a baseline for children with spina bifida (SB) undergoing VUDS in current practice at our institution. METHODS: This is a retrospective study from 2013 to 2020 of consecutive pediatric SB patients undergoing VUDS by a single provider. Patients were categorized into three groups based on age; group 1 (0-2 YR), group 2 (2-10 YR), group 3 (>10 YR). Radiation data was reported as mean air kerma (AK), dose area product (DAP) and exposure time (seconds). Effective dose (ED) was calculated based on radiation quantity (Air Kerma, AK) and organ sensitivity. The lifetime attributable risk (LAR) was calculated based on AK and a risk coefficient. Data points calculated for patients undergoing VUDS were then compared to age matched institutional VCUG data in the same age groups. RESULTS: 398 patients undergoing VUDS met inclusion criteria and 262 independent patients underwent VCUG. ED increased with age in both VUDS and VCUG. All VCUG groups were found to have a higher ED than VUDS. The LAR for VUDS groups 1-3 was 0.001, 0.002, and 0.006, respectively. Reported in percentages, there is a 0.1%, 0.2%, and 0.6% chance, respectively, of age groups 1, 2 and 3 developing cancer as a result of the radiation exposure from a VUDS. DISCUSSION: Our study found that ED was low across all age groups for VUDS, comparing favorably to the VCUG groups. VCUG was selected as a benchmark comparison for its diagnostic similarities and, at times, overlapping indications. Few studies have described ED with respect to VUDS or extrapolate the ED of VUDS into LAR in the pediatric population. We recognize that we have not determined the true ED of the gonads and bladder, rather we have overestimated, as the data is based on an international reference point proximal to the exposed individual. However, LAR was calculated for each age group and revealed that patients are at a negligible increased risk of developing malignancy secondary to exposure compared to the general population. CONCLUSION: Our current practice for pediatric VUDS has exhibited consistently low radiation exposure amongst all age groups. Moving forward, we have the foundation and flexibility to create an imaging protocol for pediatric VUDS, while taking more calculated steps toward incorporating ALARA, as low as reasonably achievable, principles. A protocol adhering to the ALARA principle could provide consistency across institutions and aid in multi-institutional studies.

Primary bladder neck obstruction in men: The importance of urodynamic assessment and cystourethrography in measuring its severity.

OBJECTIVE: Primary bladder neck obstruction (PBNO) is a condition primarily affecting young men, characterized by obstruction at the bladder neck, leading to lower urinary tract symptoms. The aim of this study was to identify a correlation between the severity of bladder neck opening impairment and urinary symptoms by means of urodynamic studies. MATERIALS AND METHODS: A retrospective analysis was conducted in adult males diagnosed with PBNO at a university neurourology department between 2015 and 2022 who underwent voiding cystourethrography (VCUG) and pressure-flow studies. The cohort was divided into two groups: absence of bladder neck opening on VCUG (Group A) and incomplete bladder neck opening (Group B). RESULTS: Out of the 82 patients with PBNO screened, 53 were included in the analysis. Nocturia was the only symptom more prevalent in Group A (65% in Group A vs. 30% in Group B, p = 0.02) but scores and subscores of the Urinary Symptom Profile questionnaire were not different between groups. In addition, the detrusor pressure at a maximum flow rate (PdetQmax), bladder outlet obstruction index (BOOI), and bladder contractility index (BCI) were higher in Group A than in Group B [PdetQmax (A = 93.7 ± 53.7 cmH2O vs. B = 65.7 ± 26.4 cmH2O; p = 0.01)-BOOI (A = 77 ± 58.3 vs. B = 48 ± 25.7; p = 0.03)-BCI (A = 136 ± 51.3 vs. B = 110 ± 41.7; p = 0.04)]. CONCLUSION: This study demonstrates a significant association between the extent of bladder neck opening impairment observed on VCUG and obstruction and contraction urodynamic parameters, but no association with the severity of urinary symptoms. Future studies should evaluate the predictive value of treatment response and the occurrence of complications based on clinical and urodynamic parameters.

Quantification of vesicoureteral reflux using machine learning.

INTRODUCTION: The radiographic grading of voiding cystourethrogram (VCUG) images is often used to determine the clinical course and appropriate treatment in patients with vesicoureteral reflux (VUR). However, image-based evaluation of VUR remains highly subjective, so we developed a supervised machine learning model to automatically and objectively grade VCUG data. STUDY DESIGN: A total of 113 VCUG images were gathered from public sources to compile the dataset for this study. For each image, VUR severity was graded by four pediatric radiologists and three pediatric urologists (low severity scored 1-3; high severity 4-5). Ground truth for each image was assigned based on the grade diagnosed by a majority of the expert assessors. Nine features were extracted from each VCUG image, then six machine learning models were trained, validated, and tested using 'leave-one-out' cross-validation. All features were compared and contrasted, with the highest-ranked then being used to train the final models. RESULTS: F1-score is a metric that is often used to indicate performance accuracy of machine learning models. When using the highest-ranked VCUG image features, F1-scores for the support vector machine (SVM) and multi-layer perceptron (MLP) classifiers were 90.27 % and 91.14 %, respectively, indicating a high level of accuracy. When using all features combined, F1 scores were 89.37 % for SVM and 90.27 % for MLP. DISCUSSION: These findings indicate that a distorted pattern of renal calyces is an accurate predictor of high-grade VUR. Machine learning protocols can be enhanced in future to improve objective grading of VUR.

[Imaging in children and adolescents with urinary tract infections]. / Bildgebung bei Harnwegsinfektionen im Kindes- und Jugendalter.

CLINICAL/METHODOLOGICAL PROBLEM: Urinary tract infections are among the most common infectious diseases in childhood. The task of imaging is to detect predisposing factors, such as urinary transport disorders, vesicoureteral reflux, as well as complications such as abscesses or pyonephrosis in addition to possible morphological changes of the kidneys and the draining urinary tract during an infection. STANDARD RADIOLOGICAL PROCEDURES: The initial diagnostic imaging technique is generally sonography. For the diagnosis of vesicoureteral reflux, voiding urosonography or alternatively radiological voiding cystourethrography are used. Further diagnostic workup may include scintigraphy, magnetic resonance imaging (MRI) or, in exceptional cases, computed tomography (CT). RECOMMENDATION FOR PRACTICE: In children and adolescents, it is of particular importance to avoid recurrent urinary tract infections and their sequelae. This requires precise imaging diagnostics, which must be performed with special consideration of radiation protection.

External validation and reliability assessment of posterior urethral morphology on initial voiding cystourethrogram as a predictor for infants with posterior urethral valves.

INTRODUCTION: The morphology of the bladder and posterior urethra on initial voiding cystourethrogram (VCUG) in posterior urethral valve (PUV) has been proposed as a meaningful early metric for short- and long-term kidney outcomes. Here, we seek to externally validate the proposed association and assess the reliability of PUV morphology characteristics. MATERIALS AND METHODS: We reviewed our institutional database for patients managed for PUV between 2000 and 2022 and included those treated with primary ablation with at least 1 year of follow-up for kidney function. Each VCUG was evaluated by three independent raters for the height-width ratio of the bladder (HW-B), height-width ratio of the posterior urethra (HW-PU), and posterior-anterior urethral ratio (PA-UR), and trabeculation (none, fine, or coarse). We assessed the reliability in these with intra-class coefficient and Fleiss kappa for continuous and categorical data, respectively. We performed univariate analysis with nadir creatinine and five-year follow-up glomerular filtration rate (GFR). RESULTS: In total, 98 patients met inclusion criteria. The median age at diagnosis and ablation was 10 and 21 days, respectively. Patients with nadir creatinine <0.8 mg/dL had higher follow-up GFR (101 vs. 20 ml/min/1.73 m2, p = 0.04), and lower risk of CKD (odds ratio 14.7, p = 0.002). The median value for HW-B was 1.4, median HW-PU was 2.1, and median PA-U was 4.7, There was significant inter-class agreement between all three measures of 0.80, 0.51, and 0.70 (p < 0.001). The inter-rater agreement for bladder trabeculation was fair (Fleiss K = 0.40, p < 0.001). There was no statistically significant correlation between HW-B, HW-PU, PU-A with nadir creatinine (p = 0.07, 0.33, 0.91) or 5-year GFR (0.27, 0.45, 0.62), respectively. DISCUSSION: There is significant interest in determining prognostic factors and metrics in PUV. The morphological characteristics on VCUG are reliable and is available information for all boys diagnosed with PUV, resulting in an attractive metric. While we do not demonstrate correlation with kidney outcomes, VCUG features warrant further attention as prognostic factors in PUV. CONCLUSIONS: PUV morphology on initial VCUG is a reliable metric of lower urinary tract deformity but is not associated with 5-year kidney outcomes.

Tethered Cord Syndrome: Role of Imaging Findings in Surgical Decision-Making.

For infants presenting with urinary problems or lower extremity weakness, imaging is ordered to investigate spinal pathology. Tethered cord syndrome (TCS) often manifests without conclusive anatomic evidence. In our case, a premature infant presented with urosepsis and was found to have an asymmetric gluteal crease and a sacral dimple. Renal ultrasound showed mild hydronephrosis, and a cystourethrogram revealed bilateral high-grade vesicoureteral reflux. Ultrasound and magnetic resonance imaging demonstrated a borderline low-lying spinal cord at the mid-L3 vertebral level. Urodynamic testing to confirm neurogenic bladder could not be completed on the first attempt due to urinary tract infection and on the second attempt due to instrument intolerance. Despite the lack of conclusive imaging evidence of a tethered cord, enough supportive clinical data was present to proceed with surgical intervention with the goal of preventing the progression of neurological dysfunction. Because TCS is ultimately a clinical diagnosis, appropriate management should not be discouraged by inconclusive or borderline imaging findings.

Vesicoureteral Reflux Diagnosis After Hospitalization for Acute Cystitis and Pyelonephritis.

Children with recurrent fevers in a short period of time need to be worked up to identify the underlying cause. Fevers in children and infants can be from many different sources. Vesicoureteral reflux (VUR) is an anatomical and physiological anomaly in children that can lead to retrograde urine flow from the bladder back into the distal ureters. This retrograde flow can cause distention, scarring, and recurrent infections including urinary tract infections (UTIs) and pyelonephritis. Identification of multiple UTIs in a short period of time should raise suspicion for a more complex pathology such as VUR and requires a more thorough workup. This workup is needed for both diagnosis and treatment. The patient in this report was seen by physicians in the emergency department, pediatric intensive care unit, nephrology, and her pediatrician. If surgery is needed, a urologist would also be involved. This report will discuss the pathophysiology of VUR and associated pathologies, diagnostic approach, medical and surgical treatment modalities, as well as prognosis.

Evaluation of Pediatric Patients with a Diagnosis of Ureterocele.

Aim: The presence and clinical importance of vesicoureteric reflux in patients with a double collecting system are being questioned. Therefore, the role of voiding cystourethrography in the management of patients with ureterocele is unclear. This study aimed to evaluate patients with a ureterocele in terms of urinary tract infection (UTI) and vesicoureteral reflux (VUR). Material Methods: The cases who were admitted to the Pediatric Nephrology Clinic of Health Sciences University Tepecik Training and Research Hospital between 2012 and 2022 and were diagnosed with ureterocele were evaluated retrospectively. Demographic, clinical, and laboratory data were obtained from file records. Results: All patients diagnosed with ureterocele and voiding cystourethrography (VCUG) were evaluated. A total of 24 (female 13 (54.2%)) children were included. The reasons for admission were antenatal hydronephrosis in 13 (54.2%) patients, UTI in 9 (37.5%) patients, and incidentally diagnosed ureterocele in 2 (8.3%) patients. Urinary tract infection was observed in 20 patients at admission, recurrent UTI in 21 patients at follow-up, preoperative pyelonephritis in 12 patients. VUR was found in 11 patients, and severe VUR (≥stage 3) was found in 9 patients. Ten patients had ipsilateral hydronephrosis, and 14 patients had a double collecting system. The presence of VUR was found to be associated with female gender, UTI at admission, and recurrent UTI at follow-up (p < 0.05). However, there was no difference between groups with or without VUR in terms of ipsilateral hydronephrosis, scar formation, and the need for surgery (p > 0.05). Conclusions: We could not demonstrate any criteria to select patients to receive VCUG; on the other hand, VUR did not cause more kidney damage. Our study supports the need for more scientific data to determine management in patients with ureterocele.

Newer Insights into Prostatic Utricle in Proximal Hypospadias.

Introduction: Prostatic utricles (PUs) are the remnants of Mullerian ducts found in the male posterior urethra. Enlarged symptomatic utricles are known to be associated with hypospadias. There is a dearth of literature defining an enlarged utricle and also its clinical significance. Aims: The aim of this study was to describe anatomical difference of PUs of cases with severe hypospadias and also to find their clinical significance if any. Materials and Methods: A prospective study was carried out, and all patients with proximal hypospadias were enrolled. Cystoscopy was performed in all cases. Symptomatology, size, and location of PU were recorded. PU of >0.5 cm was considered enlarged. Results: In the present series, a total of 70 cases were included over a period of 2 years. Enlarged utricle was found in 47/70 (67.14%) on cystoscopy. They were wide-mouthed and negotiated 9 Fr/11 Fr cystoscope with ease. Recurrent epididymo-orchitis, recurrent urinary tract infection, and obstructive features were the most common complications requiring intervention. Conclusions: PUs in boys with hypospadias are enlarged as well as wide-mouthed. Most of these remain asymptomatic, but few of them carry the potential of complications. Cystoscopy helps in direct visualization of utricular anatomy, so it should be a preferred investigating modality for investigating a PU.

Culture-positive urinary tract infection following micturating cystourethrogram in children.

Objective: To determine the incidence of culture-positive urinary tract infection (UTI) after micturating cystourethrogram (MCUG). We further wanted to identify risk factors for developing a culture-positive UTI following MCUG. Methods: A retrospective review of the available medical records of 500 paediatric patients who underwent MCUG in Perth, Western Australia was performed. Results: Seven (1.4%) patients comprised of four females and three males developed a febrile, culture-positive UTI within 14 days following MCUG. Significant association was found for female patients, patients with neurogenic bladder, and patients with previous culture-positive UTI as developing a culture-positive UTI following MCUG. Multivariate logistic regression determined that patients were more likely to develop culture-positive UTI within 14 days following MCUG if they had a known history of UTI (odds ratio: 5.0, 95% confidence interval: 1.5-17.3, p=0.010) or had a neurogenic bladder (odds ratio: 4.2, 95% confidence interval: 1.0-17.9, p=0.049). Conclusion: The incidence of patients who developed a febrile, culture-positive UTI following MCUG was low at 1.4%. Statistically significant and independent associations for the development of culture positive UTI were found in patients with neurogenic bladder and patients with previous culture-positive UTI. Further prospective studies are necessary to determine necessity of prophylactic antibiotics for high-risk patients, e.g., patients with neurogenic bladder or previous culture-positive UTI.

Model for predicting high-grade vesicoureteral reflux in young children presenting with febrile urinary tract infection.

INTRODUCTION: High-grade vesicoureteral reflux (VUR) is associated with long-term renal outcome, and can be missed if voiding cystourethrogram (VCUG) is not performed. The current febrile urinary tract infection (UTI) guidelines have narrowed down the indications for VCUG. This study aimed to determine the predictors and develop a model to predict high-grade VUR (grade III-V) in young children presenting with febrile UTI. METHODS: We retrospectively reviewed 324 children aged 2-60 months who presented with first or recurrent febrile UTI and underwent both renal and bladder ultrasonography (RBUS) and VCUG during 2004-2013. Multivariate logistic regression was used to identify independent predictors of high-grade VUR, and a predictive model and scoring system were developed. Sensitivity and specificity of the predictors were evaluated. RESULTS: Sixty-two (67.4%) of 92 children with VUR were high-grade VUR. The independent risk factors for high-grade VUR were recurrent UTI (p < 0.001), non-Escherichia coli (non-E. coli) pathogen (p = 0.011), and abnormal RBUS (p < 0.001) including pelvicalyceal dilation only (p = 0.003), and with ureteric dilation (p < 0.001). Abnormal RBUS showed highest sensitivity (58.1%), while ureteric dilation had highest specificity (96.6%) to predict high-grade VUR. Combination of these predictors improved the specificity but decreased the sensitivity. The prediction score was calculated, as follows: recurrent UTI = 3 points + non-E. coli = 1 point + pelvicalyceal dilation only = 1 point + pelvicalyceal and ureteric dilation = 3 point. A cutoff score of 1 showed sensitivity of 82.3% and specificity of 63.7%. The specificity would increase (87.8, 92.7, 97.7, 100, 100, and 100%) for higher scores of 2, 3, 4, 5, 6 and 7, respectively. DISCUSSION: High-grade VUR could be predicted by simple model using single or combined predictors. Sensitivity and specificity varied according to each predictor. The specificity of ureteral dilation was as high as recurrent UTI. The weighing score for each presenting predictor and the summation of the scores provided more detailed in sensitivity and specificity. CONCLUSIONS: Children with febrile UTI who have the predictor(s) of high-grade VUR are recommended to undergo VCUG. The high-grade VUR prediction score may help for decision-making regarding whether to perform VCUG in a particular child.

Voiding cystourethrogram: Who gets a cyclic study and does it matter?

BACKGROUND: Voiding cystourethrogram (VCUG) images the urethra and bladder during both bladder filling and emptying, as well as the ureters and kidneys when vesicoureteral reflux (VUR) is present. Given the variation in VCUG technique and reporting, the American Academy of Pediatrics Sections on Urology and Radiology published a joint standardized VCUG protocol in 2016, which included the recommendation of at least 2 voiding cycles to identify intermittent VUR and/or ureteral ectopia. STUDY DESIGN: VCUG were assessed for adherence to performance of cyclic study. Children who underwent cyclic evaluation were compared to those who underwent a single cycle VCUG. Radiation dosage was also analyzed. Studies performed on patients >18 years of age and those obtained as part of a trauma evaluation were excluded from study. RESULTS: Two hundred and eighty-four VCUGs were analyzed, 97 (34.2%) were positive for VUR on the initial cycle. Of the remaining 187 studies, 116 (62%) had multiple filling-voiding cycles while in 71 (38%) only a single cycle was performed. One hundred and sixty-one (86.1%) were negative for vesicoureteral reflux. Twenty-six (13.9%) children were diagnosed with VUR after the initial filling-voiding cycle: 6 were diagnosed with grade I, 2 grade II, 11 grade III, 2 grade IV and 5 grade V. Of the 123 total children found to have VUR, 26 (21.2%) were diagnosed after an initial negative cycle. Younger children were significantly more likely to have a cyclic study performed; mean age of patients undergoing a cyclic study was 1.09 ± 2.16 years versus 3.86 ± 4.5 years (p ≤ 0.0001). Categorically, 74.1% of children less than 1 year of age underwent a cyclic study compared to 6.9% of children older than 5 years of age (p ≤ 0.0001). There was no difference based on sex with 49.1% of males and 50.9% of females (p = 0.667) undergoing cyclic evaluation. Children undergoing a cyclic study had lower median radiation dose 2.15 microGy m2 (range 0.09-111) compared to 4.41 (range 1.3-104) [p = 0.01]. DISCUSSION: Vesicoureteral reflux may occur intermittently and cyclic VCUG is thought to enhance the ability to detect reflux. In our cohort, 26 children (9.2%) were only diagnosed after an additional cycle - ie 21.1% of reflux would have been missed had a cyclic study not been performed. The majority of these patients (69.2%, 18 of 26) were found to have dilating, and thus perhaps more clinically significant, reflux. Our study highlights the importance of obtaining as much information as possible and adhering to the standardized VCUG protocol. CONCLUSION: Younger children are more likely to undergo cyclic VCUG. While most reflux is detected with the initial filling-voiding cycle, 26 (21.2%) patients were diagnosed after an initial negative cycle with the majority being dilating VUR.

Beyond reflux: the spectrum of voiding cystourethrogram findings in the pediatric population.

Voiding cystourethrography (VCUG) is a widely accepted radiographic imaging technique that has been traditionally used for identifying vesicoureteral reflux in children. Given the simultaneous evaluation of the lower urinary tract that is afforded by VCUG, many common and uncommon abnormalities of the ureters, bladder and urethra can also be elucidated. Knowledge of the appearance of these urological entities may facilitate their proper identification.

Contemporary Management of Urinary Tract Infections in Children.

Purpose of Review: Urinary tract infection (UTI) in children is a major source of office visits and healthcare expenditure. Research into the diagnosis, treatment, and prophylaxis of UTI has evolved over the past 10 years. The development of new imaging techniques and UTI screening tools has improved our diagnostic accuracy tremendously. Identifying who to treat is imperative as the increase in multi-drug-resistant organisms has emphasized the need for antibiotic stewardship. This review covers the contemporary management of children with UTI and the data-driven paradigm shifts that have been implemented into clinical practice. Recent Findings: With recent data illustrating the self-limiting nature and low prevalence of clinically significant vesicoureteral reflux (VUR), investigational imaging in children has become increasingly less frequent. Contrast-enhanced voiding urosonogram (CEVUS) has emerged as a useful diagnostic tool, as it can provide accurate detection of VUR without the need of radiation. The urinary and intestinal microbiomes are being investigated as potential therapeutic drug targets, as children with recurrent UTIs have significant alterations in bacterial proliferation. Use of adjunctive corticosteroids in children with pyelonephritis may decrease the risk of renal scarring and progressive renal insufficiency. The development of a vaccine against an antigen present on Escherichia coli may change the way we treat children with recurrent UTIs. Summary: The American Academy of Pediatrics defines a UTI as the presence of at least 50,000 CFU/mL of a single uropathogen obtained by bladder catheterization with a dipstick urinalysis positive for leukocyte esterase (LE) or WBC present on urine microscopy. UTIs are more common in females, with uncircumcised males having the highest risk in the first year of life. E. coli is the most frequently cultured organism in UTI diagnoses and multi-drug-resistant strains are becoming more common. Diagnosis should be confirmed with an uncontaminated urine specimen, obtained from mid-stream collection, bladder catheterization, or suprapubic aspiration. Patients meeting criteria for imaging should undergo a renal and bladder ultrasound, with further investigational imaging based on results of ultrasound or clinical history. Continuous antibiotic prophylaxis is controversial; however, evidence shows patients with high-grade VUR and bladder and bowel dysfunction retain the most benefit. Open surgical repair of reflux is the gold standard for patients who fail medical management with endoscopic approaches available for select populations.

A machine learning-based approach for quantitative grading of vesicoureteral reflux from voiding cystourethrograms: Methods and proof of concept.

INTRODUCTION: The objectivity of vesicoureteral reflux (VUR) grading has come into question for low inter-rater reliability. Using quantitative image features to aid in VUR grading may make it more consistent. OBJECTIVE: To develop a novel quantitative approach to the assignment of VUR from voiding cystourethrograms (VCUG) alone. STUDY DESIGN: An online dataset of VCUGs was abstracted and individual renal units were graded as low-grade (I-III) or high-grade (IV-V). We developed an image analysis and machine learning workflow to automatically calculate and normalize the ureteropelvic junction (UPJ) width, ureterovesical junction (UVJ) width, maximum ureter width, and tortuosity of the ureter based on three simple user annotations. A random forest classifier was trained to distinguish between low-vs high-grade VUR. An external validation cohort was generated from the institutional imaging repository. Discriminative capability was quantified using receiver-operating-characteristic and precision-recall curve analysis. We used Shapley Additive exPlanations to interpret the model's predictions. RESULTS: 41 renal units were abstracted from an online dataset, and 44 renal units were collected from the institutional imaging repository. Significant differences observed in UVJ width, UPJ width, maximum ureter width, and tortuosity between low- and high-grade VUR. A random-forest classifier performed favourably with an accuracy of 0.83, AUROC of 0.90 and AUPRC of 0.89 on leave-one-out cross-validation, and accuracy of 0.84, AUROC of 0.88 and AUPRC of 0.89 on external validation. Tortuosity had the highest feature importance, followed by maximum ureter width, UVJ width, and UPJ width. We deployed this tool as a web-application, qVUR (quantitative VUR), where users are able to upload any VCUG for automated grading using the model generated here (https://akhondker.shinyapps.io/qVUR/). DISCUSSION: This study provides the first step towards creating an automated and more objective standard for determining the significance of VUR features. Our findings suggest that tortuosity and ureter dilatation are predictors of high-grade VUR. Moreover, this proof-of-concept model was deployed in a simple-to-use web application. CONCLUSION: Grading of VUR using quantitative metrics is possible, even in non-standardized datasets of VCUG. Machine learning methods can be applied to objectively grade VUR in the future.