• Childhood Kidney Diseases
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• v.5 no.1
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• pp.30-35
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• 2001

Purpose : To evaluate tile frequency of urinary tract anomalies in male neonates less than 3 months old who presented with urinary tract infection(UTI) and to evaluate a appropriate imaging approach after first UTI. Materials and methods : During a period of 5 years from March 1994 to February 1999, 65 male infants less than 3months old(range: 4-92 days, mean: 43 days) with UTI were evaluated. Ultrasound(US) and Voiding cystourethrogram(VCUG) were done in 60 patients. Due to refusal and technological problem, 5 patients were missed. 99mTc-dimercaptosuccinic acid renal scan (99mTc-DMSA renal scan) was recommended to most patients but performed in 40 patients. Renal scan was performed at least 3 months later after urinary tract infection. Results : Urinary tract anomalies were found in 26 of 65 infants. Twenty-six had vesicoureteral reflux(VUR), two had both VUR and double ureter, two had both U and posterior urethral valve. In patients with VUR, eight had renal scar or renal atrophies. In case of renal scar or atrophy, grades of VUR were III or above. Conclusion : We suggest that US and VCUG should be routinely performed in infants(<3months)with first UTI. 99mTc-DMSA renal scan should be performed only when renal parenchymal damage was observed in US and VUR grade III or above in VCUG. (J. Korean Soc Pediatr Nephrol 5 : 30- 5, 2001)

• Childhood Kidney Diseases
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• v.23 no.1
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• pp.36-42
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• 2019

Purpose: We investigated whether a renal size discrepancy on a renal sonogram (US) in children with febrile urinary tract infection (UTI) was correlated with the presence of cortical defects on their dimercaptosuccinic acid (DMSA) renal scan. Methods: We examined 911 children who were admitted consecutively to our hospital with their first episode of febrile UTI from March 2001 to September 2014. All enrolled children underwent a US and DMSA scan during admission. According to the US findings, including the renal size discrepancy, data were compared between children with positive and negative DMSA scan results. A positive DMSA scan result was defined as reduced or absent tracer localization and indistinct margins that did not deform the renal contour. Results: Mean renal lengths of the right and left kidneys were larger in children with positive DMSA scan results than in children with negative DMSA scan results ($63.2{\pm}11.3mm$ vs. $58.4{\pm}7.8mm$, P<0.001; $64.9{\pm}11.2mm$ vs. $59.9{\pm}7.9mm$, P<0.001; respectively). A significant difference was observed in both renal lengths between children with positive and negative DMSA scan results ($4.6{\pm}3.8mm$ vs. $3.3{\pm}2.6mm$, P<0.001). A multiple logistic regression analysis, revealed that a small kidney, cortical thinning, and a renal length discrepancy on US findings were significant factors for predicting the presence of cortical defects on an acute DMSA scan [P=0.028, 95% confidence interval (CI) 1.054-2.547; P= 0.004, 95% CI 1.354- 4.810; P<0.001, 95% CI 1.077-1.190, respectively]. Conclusion: In conclusion, a renal size discrepancy on US findings in children with their first episode of febrile UTI was a helpful tool for predicting the presence of cortical defects on an acute DMSA scan.

• Childhood Kidney Diseases
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• v.21 no.2
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• pp.136-141
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• 2017

Purpose: This study aimed to investigate clinical and radiological factors that may predict high-grade vesicoureteral reflux (VUR) in patients with febrile urinary tract infection (UTI). Methods: We retrospectively analyzed medical records of 446 patients diagnosed with febrile UTI from March 2008 to February 2017. All patients underwent renal-bladder ultrasonography (RBUS), 99mTc dimercaptosuccinic acid (DMSA) renal scan, and voiding cystourethrography (VCUG), and were divided in to 3 groups: a high-grade VUR group (n=53), a low-grade VUR group (n=28), and a group without VUR (n=365). Results: The recurrence and non-Escherichia coli infection rates in febrile UTI were significantly higher in the high-grade VUR group than in the other two groups (P<0.05). RBUS showed that hydronephrosis and ureter dilatation were more frequent in the high-grade VUR group than in the other groups (P<0.05). In the high-grade VUR group, a renal cortical defect was more likely to appear as multiple defects, and the difference in bilateral renal scan uptake between both kidneys was larger than in the other two groups (P<0.001). Conclusion: Recurrent UTI, non-E. coli UTI, abnormal findings on RBUS such as hydronephrosis and ureter dilatation, and abnormal findings in the DMSA renal scan such as multiple renal cortical defects and greater uptake difference were associated with high-grade VUR. VCUG should be selectively performed when RBUS and/or DMSA renal scan reveal significant abnormalities.

• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.1
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• pp.15-20
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• 2021

Purpose This article studies the relationship between the length of a kidney measured by two scanning methods: Kidney Computed Tomography (CT) and ^99mTc-Dimercaptosuccinic acid (DMSA) renal scan. Kidney CT provides a better anatomic assessment, while ^99mTc-DMSA renal scan is superior in the kidney function test. Materials and Methods From January to December of 2019, two hundred patients who had Kidney CT and Tc^99m-DMSA renal scan were chosen for this study. SPSS17.0 was selected for statistical analysis. Results Due to the effect of the breathing and resolution of ^99mTc-DMSA renal scan, it showed the kidney's relatively longer length than the length of Kidney CT. For the same kidney, the length comparison among different brands' Gamma cameras was negligible. The length difference within the same age group did not show a noticeable discrepancy. However, there was a length difference between the radio technologists. Kidney CT and ^99mTc-DMSA renal scan indicated a strong positive correlation between the length of the left and right kidney. Conclusion It is necessary to establish a standardized measurement method for measuring kidney length using ^99mTc-DMSA renal scan. The kidney's functional changes and length changes are indications of Kidney diseases. Especially, pediatric patients tend to use ^99mTc-DMSA renal scan for assessing the kidney's shape and the function to avoid potential radiation exposure during the Kidney CT. Therefore, it is significant to provide not only the kidney's functional information but also an anatomic analysis, including the kidney's size, length, and location through the ^99mTc-DMSA renal scan.

• Childhood Kidney Diseases
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• v.20 no.2
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• pp.37-44
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• 2016

Although asymptomatic bacteriuria, cystitis, and acute pyelonephritis (APN) have been categorized as urinary tract infections (UTIs), the immunopathogenesis of each disease is different. APN shows an age predilection; the majority of children (over 70-80%) with APN are under 1-2 years of age, with a male predominance. After 1-2 years of age, female predominance has been reported. This finding suggests that the immature immune state of infancy may be associated with the pathogenesis of APN. Escherichia coli is the most common etiologic agent; other uropathogens associated with UTIs originate from the host and comprise normal flora that are continuously altered by environmental factors. Therefore, uropathogens may have characteristics different from those of extraneous bacterial pathogens. Although antibiotic-resistant uropathogens, including extended-spectrum beta-lactamase-producing strains, are increasing in Korea and worldwide, treatment failure is rare in immune-competent children. The immunopathogenesis of APN remains unknown. Intact bacteria may not be the causative substances in renal cell injury; rather, smaller substances produced during bacterial replication may be responsible for renal cell injury and scarring. Moreover, substances from host cells such as proinflammatory cytokines may be involved in renal cell injury. A dimercaptosuccinic acid scan is used to detect the site of bacterial replication in the renal parenchyma, and may be influenced by the size of the focus and the stage of APN. Traditional aggressive studies used to identify vesicoureteral reflux after the first episode of APN have been modified because of rare cases of chronic kidney disease in patients with recurrent UTI.

• Childhood Kidney Diseases
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• v.20 no.2
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• pp.57-62
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• 2016

Purpose: We used technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy to identify factors predictive of renal cortical defects in infants <3 months of age with urinary tract infections (UTIs). Methods: We retrospectively reviewed data on infants <3 months of age with culture-proven UTIs treated at a single center from March 2010 to February 2016. Blood samples were obtained for laboratory evaluation prior to commencement of antibiotic therapy. The therapeutic delay time (TDT) and therapeutic response time (TRT) were recorded. All patients were divided into two groups depending on features of their DMSA scans. We compared the demographic, clinical, and laboratory characteristics of the two groups. Results: A total of 119 infants (94 males and 25 females; mean age, $56.9{\pm}21.3days$) were included. Cortical defects were evident in the DMSA scans of 47 cases (39.5%). In infants with such defects, the peak temperatures ($38.9{\pm}0.57^{\circ}C$ vs. $38.4{\pm}0.81^{\circ}C$, P=0.001), the absolute neutrophil counts ($8,920{\pm}4,460/mm$ vs. $7,290{\pm}4,090/mm$, P=0.043), and the C-reactive protein (CRP) levels ($6.49{\pm}4.33mg/dL$ vs. $3.21{\pm}2.81mg/dL$, P=0.001) were significantly higher than those in infants without cortical defects. The TDT was also longer in those with cortical defects (P=0.037). Conclusion: We found that a TDT ${\geq}8.5hr$ (odds ratio [OR] 5.81), a peak temperature ${\geq}38.3^{\circ}C$ (OR 6.19), and a CRP level ${\geq}4.96mg/dL$ (OR 7.26) predicted abnormal DMSA scan results in infants <3 months of age with UTIs.

• Childhood Kidney Diseases
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• v.21 no.2
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• pp.114-120
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• 2017

Purpose: The aim of this study was to determine the clinical characteristics, frequency of renal abnormalities and benefits of a top-down approach in children with their first febrile urinary tract infection (UTI). Methods: We reviewed 308 patients retrospectively who were admitted to Yeungnam University Hospital and were treated for their first febrile UTI from February 2006 to December 2013. We performed a comparative analysis of laboratory findings and results of imaging techniques including a Tc-99m dimercaptosuccinic acid (DMSA) renal scan. Results: Among the patients, 69% (213/308) were males, and 90% (277/308) had their first UTI episode during infancy. A DMSA renal scan was performed on all patients, and showed positive findings in 60% (184/308) of cases. Laboratory indices of inflammation were significantly higher in the DMSA-positive group (P< 0.05). There was a statistically significant difference in the age distribution between the two groups. In the DMSA-positive group, 165 patients underwent voiding cystourethrography (VCUG), and 58 (35%) cases demonstrated vesicoureteral reflux. In total, 110 patients in the DMSA-positive group, underwent repeat scanning at 6 months; 33 children (30%) demonstrated static scarring, but 77 (70%) had improved completely. The concordance of the ultrasonography (US) and VCUG was low. Older patients had more renal scarring. Conclusion: DMSA is a sensitive method for assessing the severity of inflammation and kidney injury. However, the ability of US to predict renal parenchymal damage was limited. A top-down approach in children with their first febrile UTI showed significant value.

• Childhood Kidney Diseases
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• v.26 no.1
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• pp.52-57
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• 2022

Purpose: To determine predictive factors for detecting renal parenchymal damages (RPDs) in infants with recurrent febrile urinary tract infection (fUTI). Methods: From January 2015 to December 2021, 102 infants with recurrent fUTI and who underwent ^99mTc-dimercaptosuccinic acid (DMSA) renal scan in our hospital were included in this study. Controls included infants with normal DMSA results performed 3 months apart from the 2nd episode of fUTI. DMSA-positive group included infants with positive DMSA results performed 3 months apart from the 2nd episode of fUTI or at the 3rd episode of fUTI. The recurrence rate, causative bacteria, renal size discrepancy of both kidneys, and laboratory findings including C-reactive protein (CRP) and spot urine sodium-to-potassium ratio (uNa/K) were compared between both groups. Results: Only 3.8% of 79 infants with a 2nd episode of fUTI showed positive DMSA results. fUTI recurred more frequently within 12 months of follow-up in the DMSA-positive group than in the control group (69% vs. 13%, P<0.001). CRP values were significantly higher in the DMSA-positive group than in the control group (7.3 mg/dL vs. 3.7 mg/dL, P<0.001). Spot uNa/K were significantly lower in the DMSA-positive group than in the control group (0.6 vs. 1.1, P<0.001). Conclusions: Congenital renal scar and RPDs on the DMSA scan were more frequently found in infants with recurrent fUTI than those in the control group. High CRP values and low spot uNa/K in acute infections were helpful in predicting the presence of RPD in infants with recurrent fUTI.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.212-219
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• 2007

Purpose : It is difficult to diagnose acute pyelonephritis(APN) in young children, because of their nonspecific symptoms. The younger the age, the higher the risk of renal scars after APN, which can be prevented by early diagnosis and treatment. We compare the significance of renal imaging studies by age for diagnosis of APN in febrile urinary tract infection(UTI) in children. Methods : Fifty-three hospitalized children(34 patients under age 2 and 19 patients over age 2) with febrile UTI and who had undergone dimercaptosuccinic acid(DMSA) scan, renal ultra sonography(RUS) and voiding cystourethrography(VCUG) during the acute stage were re-viewed. We compared the renal imaging studies between the different age groups. Results : The DMSA scan showed cortical defects in 23.5% of patients under age 2, which was significantly lower than 63.2% of patents over age 2(P<0.05). The renal cortical defects on DMSA scan were associated only with a high peripheral leukocyte count, but not with fever duration, erythrocyte sedimentation rate(ESR), and C-reactive protein(CRP). And there was no correlation between the DMSA scan, VCUG or RUS findings. Conclusions : The DMSA scan is not sensitive for diagnosis of APN in children less than 2 years of age and the findings cannot predict the presence of vesicoureteral reflux(VUR). VCUG may be necessary for proper management in this age group.

• Childhood Kidney Diseases
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• v.22 no.2
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• pp.42-46
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• 2018

Purpose: We investigated whether the white blood cell (WBC) count to hemoglobin (Hgb) level ratio is correlated with the presence of cortical defects on dimercaptosuccinic acid (DMSA) renal scan in children with febrile urinary tract infection (UTI). Methods: We examined 95 children who were consecutively admitted to our hospital with their first episode of febrile UTI. Blood tests (C-reactive protein [CRP], WBC, Hgb] were performed. All enrolled children underwent DMSA scanning during admission. Data were compared between children with positive and negative DMSA results. The correlations between WBC to Hgb ratio and the presence of cortical defects on DMSA scan, and between WBC to Hgb ratio and CRP level were analyzed using the Pearson chi-squared test. Multiple logistic regression analysis was used to evaluate whether WBC to Hgb ratio could predict the cortical defects on DMSA scan in children with febrile UTI. Results: The WBC to Hgb ratio was significantly higher in children with positive DMSA results than in those with negative DMSA results; positively correlated with the presence of cortical defects on DMSA scan and CRP; and was a significant factor for predicting the presence of cortical defects on DMSA scan. Conclusion: The WBC to Hgb ratio may predict the presence of cortical defects on acute DMSA scans in children with febrile UTI.