• Childhood Kidney Diseases
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• v.11 no.2
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• pp.229-238
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• 2007

Purpose : Since the first febrile UTI(urinary tract infection) in infants is commonly associated with vesicoureteral reflux(VUR), imaging studies such as renal ultrasonography, dimercaptosuccinic acid(DMSA) scan, and voiding cystourethrography(VCUG) are recommended. How-ever, because of the invasiveness of VCUG, it is difficult to perform in all young infants with febrile UTI. The purpose of this study is to compare the clinical and laboratory characteristics, radiologic findings between the young infant group(1 to 6month, n=121) and the old infant group(7 to 24months, n=91), and to determine the clinical and radiologic risk factors that predict the presence of VUR before the VCUG in patients with their first febrile UTI under 2 years of age. Methods : We reviewed the medical records of 211 first febrile UTI patients under 2 years of age retrospectively, and compared clinical, laboratory, and radiologic findings between the two age groups. Results : The young infant group had a male preponderance and a higher incidence of Escherichia coli in their urine culture. The incidence of acute renal parenchymal defects on DMSA scans were significantly increased in the young infant group. The incidence of VUR was 29% in patients who had a VCUG, but there were no differences in the incidence of VUR between the two age groups. Abnormal findings on DMSA scan significantly correlated with higher incidence of VUR in the young infant group. Incidence of abnormal findings DMSA scan significantly increased with high grade VUR(garde III-V ). Conclusion : In treating first febrile UTI patients under 2 years, physicians have to consider such characteristics as age less than 6 months, male preponderance, E.coli in the urine culture, and increased incidence of abnormal findings on DMSA scans which correlated well with the presence of VUR. The results of the DMSA scan might help us to predict the presence of VUR before the VCUG in first febrile UTI and help us to reduce performing invasive radio-logic studies especially in the young infant group. (J Korean Soc Pediatr Nephrol 2007;11:229-238)

• Childhood Kidney Diseases
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• v.22 no.2
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• pp.47-51
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• 2018

Purpose: Urinary tract infection (UTI) is one of the common infectious diseases in children. Several imaging modalities can be used to confirm the presence of acute pyelonephritis (APN). Among them the 99mTcdimercaptosuccinic acid renal scan (DMSA scan) is used as a gold standard for diagnosis. Ultrasonography technology is evolving. Therefore, in this study, we investigated the sensitivity and specificity of Power Doppler ultrasonography (PDU) compared to the results from the previous study. Methods: There were 260 patients included in this study, aged between 1 and 12 months old. The patients were admitted to the Yeungnam University Medical Center between January 2008 and December 2015. All patients underwent both DMSA scan and PDU within 5days of admission. Voiding cystourethrography (VCUG) was performed in 195 patients with abnormal DMSA scan or PDU. Results: The diagnostic sensitivity of APN using PDU was 45.5% and specificity was 85.5% in 260 patients following detection of a defect on DMSA scan that was defined as APN. The diagnostic sensitivity and specificity of PDU for VUR were 65.5 % and 60.1%, respectively. The diagnostic sensitivity and specificity of DMSA scan for VUR were 95.7% and 14.1%, respectively. Conclusion: PDU has a high specificity but low sensitivity, so there are limitations in using it to replace a DMSA scan for the diagnosis of APN in children. DMSA scan and PDU have different sensitivity and specificity in diagnosis of VUR, respectively. Therefore, we suggest that the sensitivity and specificity of each test can be helpful in diagnosing APN and VUR when used in conjunction.

• Childhood Kidney Diseases
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• v.24 no.2
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• pp.98-106
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• 2020

Purpose: The aim of this study is to evaluate the clinical utility of late 6-month dimercapto-succinic acid (DMSA) renal scan in predicting vesicoureteral reflux (VUR) and long-lasting renal scars in children with first acute pyelonephritis (APN). Methods: A retrospective case study of children admitted with APN from January 2010 to July 2017 was performed. The study included patients with voiding cystourethrography (VCUG) and acute and late 6-month DMSA scan. We analyzed the clinical, laboratory and imaging findings of patients with and without late cortical defects at 6 months and those with or without VUR. Results: Among 145 children with APN, 50 (34.5%) had cortical defects on the late DMSA renal scan and 60 (41.4%) showed VUR. Thirteen of 38 (34.2%) children undergoing 18-month DMSA renal scan showed a long-lasting renal scars. Compared with children without late cortical defects, patients with late 6-month cortical defects had a higher incidence of VUR and long-lasting renal scars, and relapse of UTI (all P<0.05). In a multivariable analysis, both high-grade VUR and relapse of UTI were independently correlated with the presence of late 6-month cortical defects (P<0.05). Late cortical defects and relapse of UTI were also associated with the presence of VUR (P<0.05). Only the late 6-mo cortical defects was an independent predictor of long-lasting renal scars in children with APN (P<0.05). Conclusion: An abnormal late 6-month DMSA renal scan may be useful in identifying VUR and long-lasting renal scars in children diagnosed with APN.

• Childhood Kidney Diseases
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• v.10 no.2
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• pp.201-212
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• 2006

Purpose : Vesicoureteral reflux(VUR) is the major risk factor of urinary tract infection(UTI) in children and may result in serious complications such as renal scarring and chronic renal failure. The purpose of this study was to evaluate the relationship between VUR and renal scar formation, the usefulness and correlation of various imaging studies in reflux nephropathy, and the spontaneous resolution of VUR. Methods : We retrospectively reviewed 106 patients with VUR with no accompanying urogenital anomalies in the Department of Pediatrics, Bundang CHA Hospital during the period from Jan. 1996 to Mar. 2005. Ultrasonography and $^{99m}Tc$-dimercaptosuccinic acid(DMSA) scan were performed in the acute period of UTI. Voiding cystourethrography(VCUG) was performed 1 to 3 weeks after treatment with UTI. Follow-up DMSA scan was performed 4 to 6 months after treatment and a follow-up VCUG was performed every 12 months. Results : The mean age at detection of VUR was $13.8{\pm}22.2$ months and the male to female ratio was 2:1. The incidence of renal scarring showed a tendency of direct correlation between severity of VUR(P<0.001) and abnormal findings of renal ultrasonography(P<0.01). 63.2%(24 of 38 renal units) of renal parenchymal defects present in the first DMSA scan disappeared on follow-up DMSA scans. Follow-up DMSA scans detected renal scars in 7(14%) of 50 renal units with ultrasonographically normal kidneys. Meanwhile, ultrasonography did not show parenchymal defects in 7(36.8%) of 19 renal units where renal scarring was demonstrated on a follow-up DMSA scan. The spontaneous resolution rate of VUR was higher(75%) in cases with low grade(I to III) VUR(P<0.01). Conclusions : The presence and severity of VUR and abnormal findings of renal ultrasonography significantly correlated with renal scar formation. DMSA scan was useful in the diagnosis of renal defects. Meanwhile renal ultrasonography was an inadequate method for evaluating renal parenchymal damage. Therefore, follow-up DMSA scans should be performed to detect renal scars even in children with low-grade VUR and normal renal ultrasonography.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.222-227
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• 2010

Purpose : To evaluate the significance of clinical signs and laboratory findings as predictors of renal parenchymal lesions and vesicoureteral reflux (VUR) in childhood urinary tract infection (UTI). Methods : From July 2005 to July 2008, 180 patients admitted with a first febrile UTI at the Pediatric Department of Konkuk University Hospital were included in this study. The following were the clinical variables: leukocytosis, elevated C-reactive protein (CRP), positive urine nitrite, positive urine culture, and fever duration both before and after treatment. We evaluated the relationships between clinical variables and dimercaptosuccinic acid (DMSA) scan and voiding cystourethrography (VCUG) results. Results : VCUG was performed in 148 patients; of them, 37 (25.0%) had VUR: 18 (12.2%) had low-grade (I-II) VUR, and 19 (10.5%) had high-grade (III-V) VUR. Of the 95 patients who underwent DMSA scanning, 29 (30.5%) had cortical defects, of which 21 (63.6%) had VUR: 10 (30.3%), low-grade (I-II) VUR; and 11 (33.3%), high-grade VUR. Of the 57 patients who were normal on DMSA scan, 8 (14.0%) had low-grade VUR and 6 (10.5%) had high-grade VUR. The sensitivity, specificity, and positive and negative predictive values of the DMSA scan in predicting high-grade VUR were 64.7%, 69.9%, 33.3%, and 89.5%, respectively. Leukocytosis, elevated CRP, and prolonged fever ($36{\geq}$ hours) after treatment were significantly correlated with the cortical defects on DMSA scans and high-grade VUR. Conclusion : Clinical signs, including prolonged fever after treatment, elevated CRP, and leukocytosis, are positive predictors of acute pyelonephritis and high-grade VUR.

• Childhood Kidney Diseases
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• v.7 no.1
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• pp.38-43
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• 2003

Purpose : Accurate diagnosis of acute pyelonephritis(APN) using clinical and laboratory parameters is often difficult in children. Clinical and experimental studies have demonstrated that renal scarring can be prevented or diminished by early diagnosis and aggressive treatment of acute pyelonephritis. dimercaptosuccinic acid(DMSA) renal scan has been reported to be useful in children for confirmation of the diagnosis of acute pyelonephritis. An analysis was undertaken to correlate the clinical and laboratory manifestations of APN With the results of the DMSA renal scan in different age groups. Methods : We determined the sensitivity of DMSA renal scan in febrile urinary tract infections(UTI) in two groups according to age : group I in less than 2 years; group II in older than 2 years. During the period March 2001 through September 2002, 67 children presented with febrile UTIs. All patients had DMSA renal scan done in the acute period, 55 had voiding cystourethrography(VCUG) and 66 had renal ultrasonogram(RUS) done. Results : There were no significant difference between the two groups in DMSA renal scan (P>0.05). But, in group I sensitivity of DMSA renal scan was 47%; in group II sensitivity of DMSA renal scan was 70%. The grade of reflux correlated with a positive DMSA renal scan. Vesicoureteral reflux did not correlate with age. RUS did not correlate with a positive DMSA renal scan in any age group. Abnormality of RUS did not correlate with age. Conclusion : At present, we believe that DMSA renal scan is the prevailing method in differention of the APN. In addition, it is not invasive and less costly. Even though there is no statistical difference in the sensitivity of DMSA renal scan between young and older children, we can observe that in the younger group, the sensitivity of DMSA renal scan seemed to be lower(47%).

• Childhood Kidney Diseases
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• v.14 no.2
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• pp.195-202
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• 2010

Purpose : The purpose of this study is to determine if there are prognostic factors leading to permanent parenchymal damages to kidney in children after acute pyelonephritis. Methods : This study was conducted in 160 pediatric patients with acute pyelonephritis admitted to Ajou University Hospital from 2000 to 2005, whose renal cortical defects were confirmed by $^{99m}Tc$-dimercaptosuccinic acid scintigraphy (DMSA scan). Along with the follow-up DMSA scan after 6 months, they were classified into two groups; recovered group (106) and scarred group (54). The clinical characteristics of each group were compared. Results : Among the total of 160 patients, 106 (66.3%) showed recovery of the initial defect (the recovered group), while 54 (33.8%) showed permanent defects on the followup DMSA scan (scarred group). Recovery rate was poor for patients of 1 year and older, or patients with the duration of fever and pyuria longer than 7 days. The recovery rate was poor in the patients with history of frequent febrile episodes and abnormal results of imaging studies, such as voiding cystourethrography (VCUG), ultrasonography. Conclusion : The recovery rate of children with renal defects on DMSA scan with acute pyelonephritis was lower when the patient is older than 1 year, when the duration of fever and pyuria exceeded 7 days, and when the patients had the histories of frequent febrile episodes and had urinary tract abnormalities on imaging studies. These findings suggest that there may be under- or mis-diagnosis of acute pyelonephritis by pediatrician.

• Clinical and Experimental Pediatrics
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• v.48 no.9
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• pp.998-1003
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• 2005

Purpose : We evaluated the occurrence of renal scarring in children with unilateral vesicoureteral reflux(VUR), and the relationships between renal scar formation and risk factors such as VUR, duration of fever, acute-phase reactant, age, and sex. Methods : We retrospectively analyzed the data of 35 children newly diagnosed with unilateral vesicoureteral reflux after urinary tract infection(UTI) in Wallace Memorial Baptist Hospital between January 1996 and December 2004. Ultrasonography, Erythrocyte sedimentation rate(ESR), and C-reactive protein(CRP) were performed initially. Voiding cystourethrography(VCUG) was performed 1 to 3 weeks after treatment with UTI. $^{99m}Tc$-dimercaptosuccinic acid(DMSA) scan was performed 4 to 6 months after treatment. Results : Scintigraphic renal damage was present in 29 percent of the refluxing and in 3 percent of the nonrefluxing kidneys(P<0.05). The severity of VUR was significantly correlated with renal scar formation(P<0.05). The duration of fever before treatmen($5.0{\pm}1.3$ vs $2.6{\pm}1.3$) and prolonged fever of over 5 days were significantly different between renal scar group and non-renal scar group(P<0.05). ESR($56.3{\pm}23.8$ vs $27.9{\pm}18.1mm/hr$, P<0.05) and CRP($12.8{\pm}7.3$ vs $3.9{\pm}3.8mg/dL$, P<0.05) at the diagnosis of UTI in the renal scar group were higher, compared to those of the non-renal scar group. There were no significant differences in age and sex between the two groups. Conclusion : The presence and grade of VUR, the duration of fever before treatment, prolonged fever over 5 days, ESR, and CRP were risk factors for renal scarring, irrespective of age and sex. Diagnosis and management of VUR, in children with UTI, is important to prevent renal scars.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.977-982
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• 2003

Purpose : This study aimed to examine the excretion of various urinary proteins in children with a history of urinary tract infection(UTI), with or without vesicoureteral reflux(VUR) or reflux nephropathy, and to identify means of predicting the severity of VUR or the presence of reflux nephropathy as indicated by these markers, and to know how these markers are changed after resolution of VUR. Methods : We studied 30 children with previous UTI, without VUR and renal scarring(group I), 12 children with VUR, without evidence of renal scarring(group II), and 34 children with VUR and renal scarring(group III). 24-hour or 12-hour urine ${\beta}_2$ microglobulin(${\beta}_2$ MG), microalbumin and N-acetyl-${\beta}$-D-glucosaminidase(NAG) were measured in each child. Urinary protein excretions were analyzed according to the degree of VUR(mild VUR : a grade reflux I-III, severe VUR : a grade reflux IV-V). Cases of bilateral VUR were graded by the higher grade of reflux detected. A total of 46 children with primary VUR were followed. Among these patients, VUR was completely resolved in 16 children. Voiding cystourethrography(VCUG) and DMSA scan were performed every year. Values for urinary markers were estimated every year. Results : 24 or 12 hour urine microalbumin and NAG excretions were significantly increased in group III compared to group I(microalbumin : $27.7{\pm}26.0mg/gCr$ vs $15.0{\pm}10.7mg/gCr$, P<0.05, NAG : $15.2{\pm}18.7U/gCr$ vs $3.4{\pm}2.2U/gCr$, P<0.05). Urinary ${\beta}_2$ MG excretions were not significantly different between groups. Urinary NAG excretions were elevated in the group of children with severe VUR compared to mild VUR($26.8{\pm}27.1U/gCr$ vs $7.6{\pm}3.8U/gCr$, P<0.05). After resolution of VUR, urinary microalbumin and NAG excretions were decreased(P<0.05). Conclusion : Urinary microalbumin and NAG may be useful clinical indicators to predict the presence of reflux nephropathy and the resolution of VUR. Especially, urinary NAG excretions may be used as a possible method to predict the severity of VUR.

• Childhood Kidney Diseases
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• v.8 no.2
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• pp.223-228
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• 2004

Purpose and Methods: Urinary tract infection(UTI) is one of the most important diseases of childhood, especially for young infants. To characterize the patients diagnosed with febrile UTI in their first 6 months of life and to explore the risk factors of recurrent UTI, a retrospective study was performed. Results: Among the 90 patients studied, 77 were boys(86%). First episodes of UTI were diagnosed at the age of $2.5{\pm}1.4$ months. These patients underwent ultrasonographic evaluation of urinary tract(n=90) and voiding cystourethrography(n=81) where 53 and 35 studies showed abnormal findings respectively, and a total of 45 cases of urinary tract anomaly including vesicoureteral reflux(VUR, n=35) were diagnosed. Normal findings on ultrasonography indicated decreased risk of VUR in boys of 1-3 months of age(n=30). 53 patients were followed up more than 6 months and 45 episodes of subsequent UTI developed in 29 patients during the first 6-month period. Patients with relapse were older than patients without relapse at the diagnosis of first UTI, but other clinical parameters including abnormal findings on the imaging studies and prophylactic antibiotics prescription were not different between the two groups. Conclusion: UTI in early infancy occurred mainly in male infants and half of the patients had structural anomalies. USG was of clinical value in detecting anomalies requiring surgical intervention, and to rule out high grade VUR in 1-3 months old boys. Results of the imaging study or prophylactic antibiotics could not modify the risk of recurrent UTI. (J Korean Soc Pediatr Nephrol 2004;8:223-228)