Top-Down versus Bottom-Up Approach in Children Presenting with Urinary Tract Infection: Comparative Effectiveness Analysis Using RIVUR and CUTIE Data.

PURPOSE: The initial imaging approach to children with urinary tract infection (UTI) is controversial. Along with renal/bladder ultrasound, some advocate voiding cystourethrogram (VCUG), ie a bottom-up approach, while others advocate dimercaptosuccinic acid (DMSA) scan, ie a top-down approach. Comparison of these approaches is challenging. In the RIVUR/CUTIE trials, however, all subjects underwent both VCUG and DMSA scan. Our objective was to perform a comparative effectiveness analysis of the bottom-up vs top-down approach. MATERIALS AND METHODS: We simulated 1,000 hypothetical sets of 500 children using RIVUR/CUTIE data. In the top-down approach, patients underwent initial DMSA scan, and only those with renal scarring underwent VCUG. In the bottom-up approach, the initial study was VCUG. We assumed all children with vesicoureteral reflux (VUR) received continuous antibiotic prophylaxis (CAP). Outcomes included recurrent UTI, number of VCUGs and CAP exposure. We assumed a 25% VUR prevalence in children with initial UTI with sensitivity analysis using 40% VUR prevalence. RESULTS: Median age of the original RIVUR/CUTIE cohort was 12 months. First DMSA scan was performed at a median of 8.2 weeks (IQR 5-11.8) after the index UTI. In the simulated cohort, slightly higher yet statistically significantly recurrent UTI was associated with the top-down compared with the bottom-up approach (24.4% vs 18.0%, p=0.045). On the other hand, the bottom-up approach resulted in more VCUG (100% vs 2.4%, p <0.001). Top-down resulted in fewer CAP-exposed patients (25% vs 0.4%, p <0.001) and lower overall CAP exposure (5 vs 162 days/person, p <0.001). Sensitivity analysis was performed with 40% VUR prevalence with similar results. CONCLUSIONS: The top-down approach was associated with slightly higher recurrent UTI. Compared to the bottom-up approach, it significantly reduced the need for VCUG and CAP.

Visualización de un divertículo pielocalicial con [99mTc]Tc-DTPA y gammagrafía con [99mTc]Tc-DMSA / Visualization of a pyelocaliceal diverticulum with [99mTc]Tc-DTPA and [99mTc]Tc-DMSA scintigraphy

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

OBJECTIVE: To assess the accuracy of renal ultrasound (RUS) in detecting renal scarring (RS). METHODS: All initial DMSA scans performed from 2006 to 2009 for history of urinary tract infection (UTI) or vesicoureteral reflux (VUR) in patients under 14 years old were identified, and clinical history obtained via chart review. Patients who had RUS within 4 months of DMSA scan and no documented UTI during that interval were included. Decreased uptake of tracer associated with loss of contours or cortical thinning defined a positive DMSA study. Increased echogenicity/dysplasia, cortical thinning, atrophic kidney and/or abnormal corticomedullary differentiation defined a positive RUS. The sensitivity and specificity of RUS in identifying RS were calculated using DMSA scan as the gold standard. RESULTS: A total of 144 patients had initial DMSA scans performed for UTI or VUR, with a RUS within 4 months, and no UTI between the 2 studies. Ninety-five of 144 (66%) had RS on DMSA and 49/144 (34%) did not. Patients with or without RS on DMSA were not different in gender (P = .073), age (P = .432), insurance (P = 1.000) or VUR grade (P = .132). Only 39/144 (27.1%) patients had positive RUS. The sensitivity of RUS for RS was 35.8% and the specificity was 89.8%, leading to an accuracy of 54.2% (95%CI; 45.7-62.5%, P = .999). CONCLUSION: RUS demonstrated poor sensitivity for RS visualized on DMSA scan. This suggests that RUS is a poor screening test for RS or indicators of future renal scar. A normal ultrasound does not rule out RS or risk of future renal scar. Specificity of RUS was excellent.

Preventive Effect of L-Carnitine on Scar Formation During Acute Pyelonephritis: A Randomized Placebo-Controlled Trial.

BACKGROUND: Urinary tract infection and pyelonephritis are clinical problems that frequently occur in children. Several factors are responsible for renal tissue injury, morbidity, and renal scarring after pyelonephritis. The aim of this study was to evaluate the preventive effect of L-carnitine on renal scarring in acute pyelonephritis. METHODS: A randomized double-blind clinical trial was conducted on 65 children aged 6 months to 10 years. Patients were randomized into 2 groups to receive 7-day treatment with only antibiotics without L-carnitine (control group; n = 32) and 7-day treatment with L-carnitine (case group; n = 33) during the acute phase of infection. Technetium-99m-labeled dimercaptosuccinic acid (DMSA) scintigraphy was performed for all children during the acute phase (in 2-7 days of hospitalization) and late phase. P-value less than 0.05 was statistically significant. RESULTS: We recruited 65 participants in the study: 32 children in control group and 33 children in case group. Three children in the control group and 2 children in the case group refused to perform the second DMSA scan. Overall, data analysis at the end of the study was done on 60 patients. Age distribution of girl patients with upper urinary infection was 6.5% in girl children aged between 6 months and 12 months, 41.1% aged between 1 and 5 years, 33.3% aged between 5 and 10 years, respectively. There was no significant difference between 2 groups in age and sex. There was no significant difference between 2 groups in systolic blood pressure, diastolic blood pressure, the lab data including urine white blood cells and serum erythrocyte sedimentation rate, and antibiogram profiles. Voiding dysfunction was detected in 10% of the participants. The baseline DMSA was not significantly difference in 2 groups, but worsening of kidney lesions was significantly higher in control group after 6 months (P = 0.012). CONCLUSION: Our study showed that L-carnitine significantly decreased renal scarring because of acute pyelonephritis.

Two-step treatment model for the adult patients with an obstructed kidney functioning below 10% of its capacity: a pilot study.

BACKGROUND: There is no written consensus as to when and in what conditions simple nephrectomy should be performed for hypo-functioning obstructed kidneys. We aimed to assess renal function and the requirement of nephrectomy in patients that underwent percutaneous nephrostomy (PCN) despite being indicated for nephrectomy due to a split renal function of less than 10% caused by ureteral obstruction. METHODS: This prospective study includes 18 patients with unilateral upper urinary tract obstruction and renal parenchymal loss on Technetium-99 m dimercaptosuccinic acid (DMSA) scintigraphy. Each patient underwent DMSA scan (DMSA-1) prior to PCN. After a 2-week follow-up period, a second DMSA scan was performed to assess renal function of each kidney (DMSA-2). Nephrectomy was performed in the kidneys functioning below 10% of their capacity, whereas kidneys functioning above 10% of their capacity were treated as appropriate to their etiologies. Renal functions and DMSA results were compared before and after nephrostomy with Paired-samples t-test and one-way ANOVA. RESULTS: Following nephrostomy, 8 (44.4%) patients had a kidney functioning above 10% of its capacity on DMSA scan and received etiology-based treatment. Glomerular filtration rates of these patients also improved significantly. A total of 9 patients who did not improve renal functions underwent nephrectomy. CONCLUSION: The results indicated that in obstructed kidneys functioning below 10% of their capacity, renal function can be recovered by using a diversion technique (such as PCN) that could alleviate the pressure within the renal pelvis and kidney parenchyma, instead of directly performing simple nephrectomy.

Current pediatric administered activity guidelines for 99m Tc-DMSA SPECT based on patient weight do not provide the same task-based image quality.

PURPOSE: In the current clinical practice, administered activity (AA) for pediatric molecular imaging is often based on the North American expert consensus guidelines or the European Association of Nuclear Medicine dosage card, both of which were developed based on the best clinical practice. These guidelines were not formulated using a rigorous evaluation of diagnostic image quality (IQ) relative to AA. In the guidelines, AA is determined by a weight-based scaling of the adult AA, along with minimum and maximum AA constraints. In this study, we use task-based IQ assessment methods to rigorously evaluate the efficacy of weight-based scaling in equalizing IQ using a population of pediatric patients of different ages and body weights. METHODS: A previously developed projection image database was used. We measured task-based IQ, with respect to the detection of a renal functional defect at six different AA levels (AA relative to the AA obtained from the guidelines). IQ was assessed using an anthropomorphic model observer. Receiver-operating characteristics (ROC) analysis was applied; the area under the ROC curve (AUC) served as a figure-of-merit for task performance. In addition, we investigated patient girth (circumference) as a potential improved predictor of the IQ. RESULTS: The data demonstrate a monotonic and modestly saturating increase in AUC with increasing AA, indicating that defect detectability was limited by quantum noise and the effects of object variability were modest over the range of AA levels studied. The AA for a given value of the AUC increased with increasing age. The AUC vs AA plots for all the patient ages indicate that, for the current guidelines, the newborn and 10- and 15-yr phantoms had similar IQ for the same AA suggested by the North American expert consensus guidelines, but the 5- and 1-yr phantoms had lower IQ. The results also showed that girth has a stronger correlation with the needed AA to provide a constant AUC for 99m Tc-DMSA renal SPECT. CONCLUSIONS: The results suggest that (a) weight-based scaling is not sufficient to equalize task-based IQ for patients of different weights in pediatric 99m Tc-DMSA renal SPECT; and (b) patient girth should be considered instead of weight in developing new administration guidelines for pediatric patients.

Asociación entre el reflujo vesicoureteral y la nefroesclerosis en las infecciones urinarias / Association of vesicoureteral reflux and renal scarring in urinary tract infections

Introducción. El objetivo del estudio fue investigar la relación entre reflujo vesicoureteral (RVU) y daño renal en pacientes con infección urinaria (IU) sin fiebre, primera IU febril e IU recurrente. El objetivo secundario, determinar si la proteína C-reactiva (PCR) actuaría como predictor de nefroesclerosis en las IU febriles. Población y métodos. Estudio prospectivo; pacientes pediátricos con IU sin fiebre, primera IU febril e IU recurrente. Los análisis de laboratorio de rutina incluyeron hemograma completo, urea, creatinina, análisis de orina completamente automatizado, urocultivo y PCR. Se realizó ecografía urológica luego del diagnóstico de IU, cistouretrografía miccional tras seis semanas y gammagrafía renal estática con ácido dimercaptosuccínico marcado con 99mTc tras seis meses a todos los participantes. Resultados. Participaron 47 niños con IU sin fiebre, 48 con primera IU febril y 61 con IU recurrente. Hubo una diferencia estadísticamente significativa entre los grupos respecto de RVU y nefroesclerosis (p= 0,001 y p= 0,011, respectivamente). También hubo una diferencia estadísticamente significativa respecto de nefroesclerosis entre los pacientes con y sin RVU (p= 0,001). Además, se estableció una diferencia estadísticamente significativa respecto de nefroesclerosis (p < 0,05) en los pacientes con PCR cinco veces mayor o menor que el valor de corte aceptado (5 mg/dl). Conclusión. La proporción de nefroesclerosis fue paralela a la frecuencia de RVU. Cuanto mayor era el grado de RVU, mayor era el daño renal. Se determinó una correlación positiva entre PCR elevada y nefroesclerosis, lo que señala esclerosis durante el diagnóstico de pielonefritis.

Introduction. The aim was to investigate the relationship between vesicoureteral reflux (VUR) and renal damage in non-febrile, febrile for the first time and recurrent urinary tract infection (UTI) patients. The secondary aim was to determine whether C-reactive protein (CRP) in febrile UTIs could be a predictor of renal scarring. Population and methods. This prospective study included non-febrile, febrile for the first time and recurrent pediatric UTI cases. The routine lab analyses comprised a complete blood count, urea, creatinine, fully automated urinalysis, urine culture and CRP analyses. All the participants were examined using urine ultrasonography subsequent to their UTI diagnosis, voiding cystourethrography (VCUG) after six weeks and Tc-99m dimercaptosuccinic acid (DMSA) static renal scintigraphy after six months. Results. There were included 47 children with non-febrile UTIs, 48 with first febrile UTIs and 61 with recurrent UTIs. A statistically significant difference was found among the groups in terms of VUR and renal scarring (p= 0.001 and p= 0.011, respectively). A statistically significant difference was also found in terms of renal scarring between patients with and without VUR (p= 0.001). Moreover, a statistically significant difference was also present in relation to renal scarring (p <0.05) in patients with five-fold lower or higher CRP values than the accepted cut-off value (5mg/dl). Conclusion. The ratio of renal scars detected was found to be parallel to the VUR frequency. The higher the VUR grade, the more renal damage was found. A positive correlation between elevated CRP and renal scarring was determined, indicating the presence of scarring during the diagnosis of pyelonephritis.

Association of vesicoureteral reflux and renal scarring in urinary tract infections. / Asociación entre el reflujo vesicoureteral y la nefroesclerosis en las infecciones urinarias.

INTRODUCTION: The aim was to investigate the relationship between vesicoureteral reflux (VUR) and renal damage in non-febrile, febrile for the first time and recurrent urinary tract infection (UTI) patients. The secondary aim was to determine whether C-reactive protein (CRP) in febrile UTIs could be a predictor of renal scarring. POPULATION AND METHODS: This prospective study included non-febrile, febrile for the first time and recurrent pediatric UTI cases. The routine lab analyses comprised a complete blood count, urea, creatinine, fully automated urinalysis, urine culture and CRP analyses. All the participants were examined using urine ultrasonography subsequent to their UTI diagnosis, voiding cystourethrography (VCUG) after six weeks and Tc-99m dimercaptosuccinic acid (DMSA) static renal scintigraphy after six months. RESULTS: There were included 47 children with non-febrile UTIs, 48 with first febrile UTIs and 61 with recurrent UTIs. A statistically significant difference was found among the groups in terms of VUR and renal scarring (p= 0.001 and p= 0.011, respectively). A statistically significant difference was also found in terms of renal scarring between patients with and without VUR (p= 0.001). Moreover, a statistically significant difference was also present in relation to renal scarring (p <0.05) in patients with five-fold lower or higher CRP values than the accepted cut-off value (5mg/dl). CONCLUSION: The ratio of renal scars detected was found to be parallel to the VUR frequency. The higher the VUR grade, the more renal damage was found. A positive correlation between elevated CRP and renal scarring was determined, indicating the presence of scarring during the diagnosis of pyelonephritis.

Introducción. El objetivo del estudio fue investigar la relación entre reflujo vesicoureteral (RVU) y daño renal en pacientes con infección urinaria (IU) sin fiebre, primera IU febril e IU recurrente. El objetivo secundario, determinar si la proteína C-reactiva (PCR) actuaría como predictor de nefroesclerosis en las IU febriles. Población y métodos. Estudio prospectivo; pacientes pediátricos con IU sin fiebre, primera IU febril e IU recurrente. Los análisis de laboratorio de rutina incluyeron hemograma completo, urea, creatinina, análisis de orina completamente automatizado, urocultivo y PCR. Se realizó ecografía urológica luego del diagnóstico de IU, cistouretrografía miccional tras seis semanas y gammagrafía renal estática con ácido dimercaptosuccínico marcado con 99mTc tras seis meses a todos los participantes. Resultados. Participaron 47 niños con IU sin fiebre, 48 con primera IU febril y 61 con IU recurrente. Hubo una diferencia estadísticamente significativa entre los grupos respecto de RVU y nefroesclerosis (p= 0,001 y p= 0,011, respectivamente). También hubo una diferencia estadísticamente significativa respecto de nefroesclerosis entre los pacientes con y sin RVU (p= 0,001). Además, se estableció una diferencia estadísticamente significativa respecto de nefroesclerosis (p < 0,05) en los pacientes con PCR cinco veces mayor o menor que el valor de corte aceptado (5 mg/dl). Conclusión. La proporción de nefroesclerosis fue paralela a la frecuencia de RVU. Cuanto mayor era el grado de RVU, mayor era el daño renal. Se determinó una correlación positiva entre PCR elevada y nefroesclerosis, lo que señala esclerosis durante el diagnóstico de pielonefritis.

Unenhanced MRI as an Alternative to 99mTc-Labeled Dimercaptosuccinic Acid Scintigraphy in the Detection of Pediatric Renal Scarring.

OBJECTIVE: The purpose of this study was to determine whether unenhanced MRI without sedation is a feasible substitute for dimercaptosuccinic acid (DMSA) scintigraphy in the detection of renal scars in pediatric patients. SUBJECTS AND METHODS: Patients scheduled for 99mTc-labeled DMSA scintigraphy for assessment of possible renal scars were recruited to undergo unenhanced MRI (free-breathing fat-suppressed T2-weighted single-shot turbo spin-echo and T1-weighted gradient-echo imaging, 13 minutes' total imaging time). Scintigraphic and MRI studies were evaluated by two independent blinded specialty-based radiologists. For each imaging examination, readers identified scars in upper, middle, and lower kidney zones and rated their diagnostic confidence and the quality of each study. The scintigraphic readers' consensus score opinion for the presence of scars was considered the reference standard. RESULTS: DMSA scintigraphy showed scarring in 19 of the 78 (24.4%) evaluated zones and MRI in 18 of the 78 (23.1%). The two MRI readers found mean sensitivities of 94.7% and 89.5%, identical specificities of 100%, and diagnostic accuracies of 98.7% and 97.4%. Interobserver agreement was 98.7% for MRI and 92.3% for DMSA scintigraphy. The MRI readers were significantly more confident in determining the absence rather than the presence of scars (p = 0.02). MRI readers were more likely to rate study quality as excellent (84.6%) than were the scintigraphic readers (57.7%) (p = 0.024). CONCLUSION: Unenhanced MRI has excellent sensitivity, specificity, diagnostic accuracy, and interobserver agreement for detecting renal scars in older children who do not need sedation. It may serve as a substitute modality, especially when DMSA is not available.

Urinary tract infection in small children: the evolution of renal damage over time.

BACKGROUND: Our objective was to analyze the evolution of kidney damage over time in small children with urinary tract infection (UTI) and factors associated with progression of renal damage. METHODS: From a cohort of 1003 children <2 years of age with first-time UTI, a retrospective analysis of 103 children was done. Children were selected because of renal damage at index 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy at least 3 months after UTI, and a late DMSA scan was performed after at least 2 years. Damage was classified as progression when there was a decline in differential renal function (DRF) by ≥4%, as regression when there was complete or partial resolution of uptake defects. RESULTS: Of 103 children, 20 showed progression, 20 regression, and 63 remained unchanged. There were no differences between groups regarding gender or age. In the progression group, 16/20 (80%) children had vesicoureteral reflux (VUR) grade III-V and 13 (65%) had recurrent UTI. In multivariable regression analysis, both VUR grade III-V and recurrent UTI were associated with progression. In the regression group, 16/20 (80%) had no VUR or grade I-II, and two (10%) had recurrent UTI. CONCLUSIONS: Most small children with febrile UTI do not develop renal damage and if they do the majority remain unchanged or regress over time. However, up to one-fifth of children with renal damage diagnosed after UTI are at risk of renal deterioration. These children are characterized by the presence of VUR grades III-V and recurrent febrile UTI and may benefit from follow-up.

Comparison of 99mTc-DMSA renal scintigraphy with biochemical and histopathological findings in animal models of acute kidney injury.

Biochemical and histological assays are currently used for the diagnosis and characterization of kidney injury. The purpose of this study was to compare technetium-99m-labeled dimercaptosuccinic acid (99mTc-DMSA) renal scintigraphy, as a non-invasive method, with common biochemical and histopathological methods in two animal models of acute kidney injury. Nephrotoxicity was induced either by gentamicin (100 mg/kg/day for one week) or unilateral ureteral ligation (UUO). Renal scintigraphy was performed 1 h after intravenous injection of 99mTc-DMSA (3 mCi). Furthermore, plasma levels of blood urea nitrogen (BUN), creatinine, sodium, and potassium were determined using an autoanalyzer. At the end of experiments, kidneys were excised for the measurement of activity uptake (mCi/gr) using a dose calibrator as well as histopathological examinations with hematoxylin and eosin (H&E) staining. There was a significant decrease in 99mTc-DMSA uptake in both gentamicin (P value = 0.049) and UUO (P value = 0.034) groups, and it was more significant in the former. The levels of BUN and creatinine increased in both gentamicin and UUO groups, while the levels of sodium and potassium remained unchanged. Furthermore, a strong correlation was found between DMSA uptake and histopathological findings. Scintigraphy with 99mTc-DMSA is capable of detection of kidney injury in both gentamicin and UUO groups. Moreover, a significant correlation was found between scintigraphy parameters and histopathological findings. This suggests 99mTc-DMSA as a non-invasive method for the evaluation of kidney injury induced by drugs or anatomical disorders.

Computing quantitative indicators of structural renal damage in pediatric DMSA scans / Cómputo de indicadores cuantitativos de daño renal estructural en imágenes DMSA pediátricas

Objectives. The proposal and implementation of a computational framework for the quantification of structural renal damage from 99mTc-dimercaptosuccinic acid (DMSA) scans. The aim of this work is to propose, implement, and validate a computational framework for the quantification of structural renal damage from DMSA scans and in an observer-independent manner. Materials and methods. From a set of 16 pediatric DMSA-positive scans and 16 matched controls and using both expert-guided and automatic approaches, a set of image-derived quantitative indicators was computed based on the relative size, intensity and histogram distribution of the lesion. A correlation analysis was conducted in order to investigate the association of these indicators with other clinical data of interest in this scenario, including C-reactive protein (CRP), white cell count, vesicoureteral reflux, fever, relative perfusion, and the presence of renal sequelae in a 6-month follow-up DMSA scan. Results. A fully automatic lesion detection and segmentation system was able to successfully classify DMSA-positive from negative scans (AUC=0.92, sensitivity=81% and specificity=94%). The image-computed relative size of the lesion correlated with the presence of fever and CRP levels (p<0.05), and a measurement derived from the distribution histogram of the lesion obtained significant performance results in the detection of permanent renal damage (AUC=0.86, sensitivity=100% and specificity=75%). Conclusions. The proposal and implementation of a computational framework for the quantification of structural renal damage from DMSA scans showed a promising potential to complement visual diagnosis and non-imaging indicators (AU)

Objetivos. En el presente trabajo se propone, implementa y valida un entorno computacional de cuantificación de imágenes con 99mTc-ácido dimercaptosuccínico (DMSA) con el objetivo de obtener indicadores cuantitativos del daño renal subyacente. Estos indicadores se validan en un contexto de imágenes DMSA pediátricas, dada su relevancia en el diagnóstico de pielonefritis aguda y cicatrices renales. Materiales y métodos. Partiendo de un conjunto de 16 imágenes DMSA positivas para daño renal y 16 controles apareados por edad y sexo, se proponen y calculan una serie de indicadores cuantitativos basados en el área relativa lesionada y la distribución de su histograma. Se implementan aproximaciones manuales y automáticas para dicho cómputo. Los indicadores obtenidos se correlacionan con otras variables clínicas de interés en este contexto, como la proteína C reactiva, la cuenta leucocitaria, el reflujo vesicouretral, la fiebre, la perfusión relativa, y la presencia de secuelas renales en la imagen DMSA a los 6 meses de seguimiento. Resultados. El sistema implementado de detección y cuantificación de lesiones renales obtuvo un rendimiento significativo discriminando las imágenes DMSA positivas de las negativas (AUC=0,92, sensibilidad=81% y especificidad=94%). El indicador de área relativa de la lesión correlacionó con los niveles de proteína C reactiva y la presencia de fiebre (p<0,05). Finalmente, un indicador derivado de las propiedades del histograma de la lesión obtuvo un rendimiento significativo en la detección de la presencia de secuelas renales (AUC=0,86, sensibilidad=100% y especificidad=75%). Conclusiones. La propuesta e implementación de un entorno computacional para la obtención de indicadores cuantitativos a partir de imágenes DMSA muestra un potencial prometedor para complementar el diagnóstico visual (AU)

Evaluation of a crossed fused renal ectopia in a paediatric patient using 99mTc-DMSA SPECT/CT / Ectopia renal cruzada con fusión en un paciente pediátrico evaluado con 99mTc-DMSA SPECT/TC

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Simple renal cyst and renal dysfunction: A pilot study using dimercaptosuccinic acid renal Scan.

AIM: Little is known about the association between renal cyst and renal dysfunction. We evaluated the deterioration of renal function in patients with unilateral, large, simple renal cysts. METHODS: Fifty patients with unilateral, simple renal cysts measuring ≥ 4 cm (cyst group) and 50 kidney donors (control group) were enrolled. Dimercaptosuccinic acid (DMSA) renal scans were performed to calculate split renal function. The differences between split renal function were calculated and compared. Clinical factors affecting decreased renal function in the cyst group were assessed. RESULTS: The mean age of the patients in the cyst group was higher than the control group (59.1 vs 39.2 years; P = 0.001). Patients with renal cysts tended to be diagnosed with hypertension (P = 0.001), However, the two groups did not significantly differ in terms of the other characteristics. The median cyst size was 7.2 cm (range, 4.5-14.2), and 31 of the 50 patients (60.2%) in the cyst group demonstrated decreased renal function in the cystic kidney units (median: 5.8%; range, 0.2-33). Although there were no differences in split renal function (50.1% vs 49.9%; P = 0.629) in the control group, the relative renal function of the cystic kidney units were significantly lower than the contralateral kidney units in the cyst group (48.3% vs 51.7%; P = 0.001). The decrease in relative renal function (>8%) in the cystic kidney units was associated with a higher serum uric acid levels and higher RENAL complexity (P = 0.035 and P = 0.007, respectively). CONCLUSION: A significant proportion of unilateral, large, simple renal cysts are associated with decreased relative renal function on DMSA renal scans.

Effect of percutaneous nephrolithotomy on renal functions in children: assessment by quantitative SPECT of (99m)Tc-DMSA uptake by the kidneys.

OBJECTIVE: To determine the impact of percutaneous nephrolithotomy (PNL) on global and regional renal function in children. METHODS: In total, 40 children (41 renal units) undergoing PNL were included in this prospective study. All patients were evaluated using quantitative single-photon emission computed tomography (QSPECT) with technetium-99 m-dimercaptosuccinic acid ((99m)Tc-DMSA) examinations before and 3 months after surgery. RESULTS: The mean age was 9.5 years (range, 3-16), and the mean stone size was 3.4 cm (range, 2-6.5). Of the cases, 39 (95%) were managed as being stone-free after a single session of PNL. After additional treatment procedures, 40 (97.5%) of the cases were managed as being stone-free. Of the 41 renal units, new focal cortical defects on (99m)Tc-DMSA scans were seen in 4 (9.7%) patients. Total relative uptake in the treated kidneys increased from 42.3% to 44.1%. The mean creatinine level before PNL was 1.18 ± 0.45 (0.8-1.6) mg/dL compared with 1.16 (0.7-1.5) mg/dL by the end of the follow-up period (not statistically significantly different, p > 0.05). CONCLUSIONS: PNL in children is a safe and feasible method for the maximal clearance of stones. QSPECT of (99m)Tc-DMSA confirmed that renal function is preserved or even improved after percutaneous stone removal.

¿Qué marcadores son útiles como predictores de cicatrices renales en niños con infección urinaria? / What markers are useful as predictors of renal scarring in children with urinary tract infection?

Tras una infección urinaria la aparición de cicatrices renales puede ocurrir entre el 10 y el 15% de los casos y tradicionalmente se ha relacionado con diferentes factores como alteraciones en la ecografía o con reflujo vesicoureteral significativo. El estudio que valoramos es un metaanálisis con datos de pacientes individuales, cuyo objetivo es analizar estos factores de riesgo y desarrollar un modelo de predicción clínica con una muestra significativa. Este estudio tiene algunas debilidades metodológicas, pero los resultados de la revisión sistemática evaluada están correctamente sintetizados y descritos. Las conclusiones están justificadas y son útiles. Con los datos del estudio, solo tres variables clínicas servirían como marcadores de cicatrices renales: las alteraciones en la ecografía, la presencia de fiebre > 39 °C y un germen diferente al Escherichia coli en el cultivo obtenido de forma apropiada. No obstante, por las mencionadas limitaciones, debería comprobarse en un estudio prospectivo. La cistouretrografía miccional seriada (CUMS), según este estudio y las recomendaciones de las guías de práctica clínica, solo debería realizarse en un pequeño subgrupo de pacientes, cuando esté indicado (AU)

After a urinary tract infection (UTI), the risk of renal scarring can occur from 10 to 15% of cases and has traditionally been related to different factors such as changes in the ultrasound or significant vesicoureteral reflux. The study we evaluate is a meta-analysis of individual patient data, which aims to analyze these risk factors and develop a clinical prediction model with a significant sample. This study has some methodological weaknesses, but the results of the systematic review evaluated are successfully synthesized and described. The conclusions are justified and useful. With the survey data only three clinical variables serve as markers of renal scarring: abnormal ultrasound, the presence of fever > 39 °C and a different seed to Escherichia coli culture obtained in an appropriate manner. Nevertheless, due to its limitations, these findings should be checked in a prospective study. The voiding cystourethrogram, according to this study and recommendations of clinical practice guidelines should only be performed on a small subset of patients, when indicated (AU)

Role of procalcitonin in predicting dilating vesicoureteral reflux in young children hospitalized with a first febrile urinary tract infection.

OBJECTIVE: The aim of this article was to assess the usefulness of procalcitonin (PCT) as a marker for predicting dilating (grades III-V) vesicoureteral reflux (VUR) in young children with a first febrile urinary tract infection. METHODS: Children ≤2 years of age with a first febrile urinary tract infection were prospectively evaluated. Serum samples were tested for PCT at the time of admission to a tertiary hospital. All children underwent renal ultrasonography (US), Tc-dimercaptosuccinic acid renal scan, and voiding cystourethrography. The diagnostic characteristics of PCT test for acute pyelonephritis and dilating VUR were calculated. RESULTS: Of 272 children analyzed (168 boys and 104 girls; median age, 5 months), 169 (62.1%) had acute pyelonephritis. There was VUR demonstrated in 97 (35.7%), including 70 (25.7%) with dilating VUR. The median PCT value was significantly higher in children with VUR than in those without (P < 0.001). Using a PCT cutoff value of ≥1.0 ng/mL, the sensitivity and negative predictive value for predicting dilating VUR were 94.3% and 95.4%, respectively, for PCT, and 97.1% and 97.8%, respectively, for the combined PCT and US studies, whereas the positive and negative likelihood ratios were 2.03 and 0.107, respectively, for PCT, and 1.72 and 0.067, respectively, for the combined studies. By multivariate analysis, high PCT values and abnormalities on US were independent predictors of dilating VUR. CONCLUSIONS: PCT is useful for diagnosing acute pyelonephritis and predicting dilating VUR in young children with a first febrile urinary tract infection. A voiding cystourethrography is indicated only in children with high PCT values (≥1.0 ng/mL) and/or abnormalities found on a US.

Rapid estimation of split renal function in kidney donors using software developed for computed tomographic renal volumetry.

PURPOSE: To evaluate the speed and precision of split renal volume (SRV) measurement, which is the ratio of unilateral renal volume to bilateral renal volume, using a newly developed software for computed tomographic (CT) volumetry and to investigate the usefulness of SRV for the estimation of split renal function (SRF) in kidney donors. METHOD: Both dynamic CT and renal scintigraphy in 28 adult potential living renal donors were the subjects of this study. We calculated SRV using the newly developed volumetric software built into a PACS viewer (n-SRV), and compared it with SRV calculated using a conventional workstation, ZIOSOFT (z-SRV). The correlation with split renal function (SRF) using (99m)Tc-DMSA scintigraphy was also investigated. RESULTS: The time required for volumetry of bilateral kidneys with the newly developed software (16.7±3.9s) was significantly shorter than that of the workstation (102.6±38.9s, p<0.0001). The results of n-SRV (49.7±4.0%) were highly consistent with those of z-SRV (49.9±3.6%), with a mean discrepancy of 0.12±0.84%. The SRF also agreed well with the n-SRV, with a mean discrepancy of 0.25±1.65%. The dominant side determined by SRF and n-SRV showed agreement in 26 of 28 cases (92.9%). CONCLUSION: The newly developed software for CT volumetry was more rapid than the conventional workstation volumetry and just as accurate, and was suggested to be useful for the estimation of SRF and thus the dominant side in kidney donors.

Renoprotective effect of erdosteine in rats against gentamicin nephrotoxicity: a comparison of 99mTc-DMSA uptake with biochemical studies.

Erdosteine is a mucolytic agent having antioxidant properties through its active metabolites in acute injuries induced by pharmacological drugs. This study was designed to investigate the renoprotective potential of Erdosteine against gentamicin (GM)-induced renal dysfunction by using Technetium-99 m dimercaptosuccinic acid (Tc-99 m DMSA) uptake and scintigraphy in rats. For this purpose, male Wistar rats were randomly allotted into one of the four experimental groups: Control, Erdosteine, GM, and GM + Erdosteine groups. GM and GM + Erdosteine groups received 100 mg/kg GM intramuscularly for 6 days. In addition, Erdosteine and GM + Erdosteine groups received 50 mg/kg Erdosteine orally for 6 days. Renal function tests were assessed by serum blood urea nitrogen (BUN), creatinine levels, as well as scintigraphic and tissue radioactivity measurements with Tc-99 m DMSA. Renal oxidative damage was determined by renal malondialdehyde (MDA) levels, by antioxidant enzyme activities; superoxide dismutase (SOD) and catalase (CAT) and activities of oxidant enzymes; xanthine oxidase (XO) and myeloperoxidase (MPO). GM administration resulted in marked renal lipid peroxidation, increased XO and MPO activities and decreased antioxidant enzyme activities. GM + Erdosteine group significantly had lower MDA levels, higher SOD and CAT activities and lower XO and MPO activities, when compared to GM. Also GM + Erdosteine had lower levels of serum BUN, creatinine and higher renal tissue Tc-99 m DMSA uptake and radioactivity with respect to GM. In conclusion, our results supported a protective role of Erdosteine in nephrotoxicity associated with GM treatment.