• Childhood Kidney Diseases
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• v.21 no.2
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• pp.94-100
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• 2017

Purpose: The American Academy of Pediatrics provides guidelines for managing febrile urinary tract infection (UTI) in infants and children 2-24 months old, but little guidance is offered regarding UTIs in those younger than 8 weeks of age. The definition of UTI is unclear and whether to proceed with micturating cystourethrography (MCUG) or $^{99m}$technetium-dimercaptosuccinic acid (DMSA) scintigraphy scan in this age group is controversial. Methods: We retrospectively analyzed 29 neonates and infants younger than 2 months of age who underwent late DMSA scans 9 months following the first episode of febrile or symptomatic UTI between July 2009 and June 2016. Results: In total, 192 children aged 0-24 months underwent ultrasound and DMSA scans (MCUG in 174/192). Neonates and infants younger than 2 months of age were significantly less likely to develop fever, and had a lower fever peak, shorter duration of fever before admission and after starting antibiotics, longer hospitalization period, lower C-reactive protein, and greater incidence of nonEscherichia coli infection. There was no difference in pyuria response at diagnosis. The prevalence rates of an ultrasound abnormality (28%), vesicoureteral reflux (28%), UTI recurrence (38%), and renal scarring (10%) in infants younger than 8 weeks of age were similar to those in children 2-24 months old. Conclusion: Neonates and infants younger than 2 months of age with UTI warrant special consideration because the fever response used for diagnosis in older children may be absent or blunted. Clinical guideline is needed for the diagnosis and management of UTI in this age group.

• Childhood Kidney Diseases
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• v.12 no.2
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• pp.186-193
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• 2008

Purpose : Intrarenal reflux(IRR) is backflow of urine from the renal pelvis into the collecting ducts. IRR is the main cause of renal injury in children with vesicoureteral reflux (VUR) which leads to renal scars, hypertension, proteinuria, and chronic renal failure. The purpose of our study was to investigate the characteristics of intrarenal reflux. Method : We retrospectively reviewed the medical records of 80 patients who were diagnosed as having grades of III-V VUR from Jan. 2004 to Dec. 2006 in the department of pediatrics in Ajou University Hospital. The patients were divided into two groups according to the presence of IRR on voiding cystoureterogram and compared to each other for the possible factors associated with intrarenal reflux. Results : Among 80 VUR patients, IRR(＋) group comprised 17(21.3%) patients and 27 renal units(23.2%) and revealed younger age, higher grade of VUR, and more proteinuria compared to IRR(-) group. There were no significant difference in gender, laboratory findings and the rate of resolution in VUR or defects on renal scan between two groups. Also, intrarenal reflux mostly corresponded to the same site of photon defects on DMSA scan. Conclusion : We suggest that intrarenal reflux tends to be associated with younger age, higher grade of reflux, more proteinuria with no difference in resolution rate of VUR when compared to the VUR patients without IRR. From this study, we were able to understand the characteristics of intrarenal reflux in children with urinary tract infection.

• Childhood Kidney Diseases
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• v.14 no.1
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• pp.71-78
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• 2010

Purpose : Hydronephrosis is found about 30% of children with urinary tract infection (UTI). It can be caused by various conditions, although most childhood hydronephrosis is congenital. This study was performed to investigate the relationship between febrile UTI and hydronephrosis. Methods : We retrospectively reviewed the medical charts of 183 patients diagnosed as UTI between January 2007 and May 2009 at Korea University Guro Hospital. Inclusion criteria were as followings; 1) fever more than $37.5^{\circ}C$ measured in the axilla, 2) positive urine culture, 3) no history of urinary tract anomaly on antenatal sonography and urinary tract infection. We classified the enrolled children into two groups of patients with hydronephrosis (HN) and those without hydronephrosis (NHN). Results : The 80 patients were HN and 103 patients NHN. Hydronephrosis was found in 58 patients with left kidney, 8 right and 14 both kidneys. Most of hydronephrosis were of low grade. Compared with NHN group, initial renal cortical defects on DMSA scan significantly increased in HN group (HN 37.5%, NHN 16.5%, P<0.05). The incidence of VUR was not different between the two groups (HN 22%, NHN 12.1%). White blood cell counts and C-reactive protein were not different between the two groups. Follow-up DMSA scan (about 6 months later after UTI) showed no difference of renal scarring in both two groups. Conclusion : Our data suggests that hydronephrosis in febrile UTI patients is clinically useful for detecting renal cortical defects, but is not associated with follow-up renal scar.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.327-332
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• 1992

$^{99m}Tc-dimercaptosuccinic$ acid (DMSA) 주사후 일정시간에 측정한 절대적 신섭취량은 기능이 살아있는 신피질량과 관계있다. 소아의 신기능은 출생후 계속 성숙되어 생후 약 $1\sim2$년에 성인의 기능에 도달하는데 DMSA섭취도 성인과는 다른 양상을 보일 것으로 기대되며 신질환에서 절대적 신섭취율의 평가는 연령을 고려해야 할 것이다. 저자들은 DMSA 스캔을 시행한 소아 환자를 대상으로 스캔상 피질 결손이 없으며 양측신의 섭취율이 비슷하고 혈중 크레아티닌치가 정상인 경우를 대조군으로 하여 연령별 DMSA의 절대적 신섭취율을 구하였고 방광요관역류를 가진 환아를 대상으로 DMSA스캔을 시행하고 신섭취율을 조사하였다. 1) 대조군은 모두 65명으로 좌우측 신섭취율의 유의한 차이는 없었으며 연령에 따라 2세경에 플라토에 도달하였는데 한쪽 신장의 평균섭취율은 3개월 미만이 $14.5{\pm}3.1%$ ID, 3개월에서 6개월 미만이 $17.2{\pm}2.1%$ID, 6개월에서 1년 미만이 $18.4{\pm}1.3%$ID, 1년에서 1년6개월 미만이 $19.3{\pm}1.1%$ID, 1년 6개월에서 2년 미만이 $21.9{\pm}2.0%$ID, 2세이상 15세이하가 $20.1{\pm}0.6%$ID였으며 전체 평균섭취율은 $19.4{\pm}0.5%$ID (injected dose, $mean{\pm}S.E.$)였다. 2) 방광요관역류를 가진 환아는 55명 (일측성 56명, 양측성 29명)으로 109신장을 대상으로 하였다. 방광요관역류의 정도와 피질결손의 수와는 대체로 비례관계가 있었으나 방광요관역류가 없으면서 피질결손이 있는 경우가 25신장중 2예 (8%)였으며, 방광요관역류가 있는 84신장중 27예 (32.1%), 이중에서 방광요관역류가 3도 이상인 62신장중 13예 (21%)에서는 피질결손이 없었다. 3) 이환신의 DMSA 섭취율을 연령에 따른 대조군의 섭취율에 대한 비(섭취율비)로 나타내면 한쪽에 역류가 있을 때 이환신의 경우 $0.55{\pm}0.06$, 정상신의 경우 $1.34{\pm}0.05$이었으며, 양쪽에 역류가 있을 때는 평균 $0.82{\pm}0.08$ $(mean{\pm}S.E.)$ 이었다. 4) 피질결손이 있는 신장의 절대 DMSA 신섭취율은 감소되어 있었고 상대측 신장의 섭취율은 피질 결손이 있더라도 대상적인 증가의 경향을 보였다. 이상의 결과로 소아에서 DMSA 절대적 신섭취율의 연령에 따른 변화를 알 수 있었으며 방광요관역류의 정도와 피질결손의 정도가 반드시 비례하지만은 않아서 시간경과에 따른 추후 검사가 필요하리라 생각된다. 또한 방광요관역류가 있는 환아에서 DMSA 섭취율로 신기능을 평가할 때, 특히 영유아에서 연령에 따른 고려가 있어야 할 것으로 보인다.

• Childhood Kidney Diseases
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• v.8 no.2
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• pp.239-243
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• 2004

Acute poststreptococcal glomerulonephritis(APSGN) is the most common form of postinfectious glomerulonephritis, and acute pyelonephritis(APN) is the most severe form of urinary tract infection in childhood. However, the concurrence of two diseases is uncommon in the literature. We describe a case of APSGN accompanied with APN in a 5-year-old female who presented with fever, left flank pain, headache and facial edema. Urinalysis showed pyuria, microscopic hematuria, and mild proteinulra. Serial urine cultures grew Escherichia coli. ${^99m}$Tc-DMSA renal scan revealed a cortical defect in the upper pole of left kidney. She had a history of preceding pharyngitis, in addition, showed high blood pressure, high anti-streptolysin 0 titer, and low serum complement levels. The patient improved completely with supportive treatment, Including antibiotic and antihypertensive therapy. These findings suggested that APSGN and APN could be manifested simultaneously or be .superimposed on each other.

• Childhood Kidney Diseases
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• v.15 no.2
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• pp.179-183
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• 2011

Abrupt progression of renal scarring associated with vesicoureteral reflux (VUR) is rare in males over 2 years old of age. We report a 5 year old boy with sustained unilateral high grade VUR who experienced abrupt progression of renal scarring; he had a relative renal radionuclide uptake of 38% at 2 years of age that dropped to 8% after three years. Per his parent's wishes, he took prophylactic antibiotics for 25 months after his first febrile urinary tract infection (UTI) at 4 months old without surgical management. One episode of recurrent breakthrough infection occurred at the age of 2 years. This observation reminds us that a recommending surgical management for sustained high grade VUR associated with renal scarring might be needed. Close follow up of DMSA for renal scanning, and long term follow up of patients after the first febrile UTI are important.

• Childhood Kidney Diseases
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• v.24 no.1
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• pp.27-35
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• 2020

Purpose: Urinary tract infections (UTIs) are the most common and serious bacterial infections in children. Therefore, early diagnosis of vesicoureteral reflux (VUR) for treatment planning and the identification of noninvasive markers that can predict renal injury are important in patients with UTIs. We analyzed the clinical features of pediatric UTIs commonly encountered by general practitioners and reinterpreted the blood tests and imaging findings to identify the important clinical predictive markers of VUR in order to selectively perform VCUG. Methods: This retrospective study was performed among 183 children diagnosed with a UTI or acute pyelonephritis. Results: The most significant predictor of high grade and bilateral VUR identified using area under the curve analyses was hydronephrosis on kidney ultrasound images with renal cortical defects on dimercaptosuccinic acid (DMSA) kidney scan simultaneously, followed by hydronephrosis only on kidney ultrasound. Conclusion: The presence of hydronephrosis on kidney ultrasound images or cortical defects or asymmetric kidneys on the DMSA kidney scans can be predictive markers of VUR, reducing the need for VCUG. Our study can thus help minimize the exposure to radiation among patients through selective VCUG.

• Childhood Kidney Diseases
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• v.13 no.1
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• pp.40-48
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• 2009

Purpose : This study was performed to identify factors related to the resolution of primary vesicoureteral reflux (VUR) in infants. Methods : We reviewed 183 infants (M : F=149 : 34) diagnosed as urinary tract infection (UTI) between February 2002 and July 2007 at Sanggye Paik Hospital. The diagnosis of UTI was made by culture from a urine specimen obtained by suprapubic puncture (n=97), catheterization (n=83), or collection bag method (n=3, twice positive culture of same organism). All of the infants were performed renal ultrasonography, DMSA scan and voiding cystourethrography (VCUG) study. Follow-up imaging consisted of contrast VCUG or direct isotope VCUG at interval of 1 year. We evaluated the relationship of clinical and laboratory finding, radiologic finding in infants with VUR. Results : Among 51 VUR patients, 18 infants had grade I-II, 12 infants had grade III and the other 21 patients had grade IV-V. Abnormal findings including hydronephrosis on renal ultrasonography were not correlated with severity of VUR. However, the incidence of renal defect in the first DMSA scan showed a tendency of direct correlation with severity of VUR in female patients only (P<0.001). There was significant difference of resolution rate in three VUR groups (grade I-II, III, IV-V) in male patients only (P=0.025). Resolution rate was higher for male patients with unilateral VUR than bilateral (P<0.001). But unilaterality had not any affect on VUR resolution in female VUR patients (P=0.786). Resolution rate was higher for VUR patients without renal scar than VUR patients with renal scar (P<0.001). Conclusion : According to our findings, grade of VUR, laterality and renal scar are the factors that contribute to resolution of primary VUR in male and female infants differently.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.37-43
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• 2015

Purpose $^{99m}Tc-DMSA$ renal scintigraphy serves as location, size and shape of kidney, so it has been used for diagnosis and passage observation after the operation or treatment. There are 3 methods of calculating the relative renal uptake ratio such as geometric mean of the counts from the anterior and posterior views, arithmetical mean from the only posterior view and posterior view which applied the renal depths. In this study, we seek to correlation between the change of total relative uptake ratio according to different inspection methods of obtaining the renal count rate. Materials and Methods The phantom experiments proceeded 5 times depending on each renal depth with the kidney phantom and tissue equivalent materials. In the clinical research, we investigated 36 adult patients who had visited our hospital from february to october, 2014 and received $^{99m}Tc-DMSA$ renal scan. The equipment was used as a gamma camera named INFINIA (General Electric Healthcare, milwaukee, USA) and we drew the region of interests through semiautomatic method by using Xeleris Ver. 2.1220 of GE. In addition, we obtained the lateral view of kidney to measure the renal depth of each patient. Then the results were compared with 3 methods of calculating relative renal uptake ratio. Results The phantom studies show when the difference between the left ant right kidney depth were less than 1 cm, there were no statistically significant difference among values calculated through anterior and posterior views and only posterior view (P>0.05), while the excess of 1cm, the results showed a statistically significant change in the value (P<0.05). In case of clinical research, the correlation between total relative uptake ratio by obtaining both sides of image and posterior view applied the kidney depth (r=0.999) was higher than by obtaining only posterior view and applying the kidney depth to one side image (r=0.988). Conclusion This study has found that, the difference of calculating total relative uptake ratio compared with obtaining anterior and posterior views and only posterior view. In order to reduce the error, we recommend the method of obtaining anterior and posterior views and is considered to be useful, particularly the patients have similar uptake ratio of left and right kidney and difficulties of measurements of kidney depth.

• Childhood Kidney Diseases
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• v.9 no.2
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• pp.193-200
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• 2005

Purpose : An atrophic renal scar(RS) is one of the underlying causes for childhood hyper tension and chronic renal failure. The risk factors for atrophic renal scar were evaluated. Methods : 41 children, who presented with first febrile urinary tract Infection at the Ewha Womans University Hospital between 1995 and 2003 and had generalized atrophic RS on $^{99m}Tc-DMSA$ renal scan, were retrospectively studied. Atrophic RS was divided into severe atrophic RS(n=14) if relative uptake on renal scan was below 10$\%$, or mild atrophic RS(n=27) if relative uptake on renal scan was between 10-35$\%$. RS was defined as congenital if the scar was detected on the first renal scan, and as acquired if the scar developed on the follow-up renal scan from acute pyelonephritis of the first renal scan. The control group was consisted of randomly selected 41 children with segmental RS. The risk factors for atrophic RS such as the generation time, VUR, gender and ACE gene polymorphism were evaluated. Results : The age distribution of atrophic RS and segmental RS did not differ significantly (P>0.05). The rate of congenital RS in atrophic RS was 61.0$\%$(25/41), which was significantly higher than 9.8$\%$(4/41) of segmental RS(P<0.01). Atrophic RS developed mote frequently in male children(M:F 68.3$\%$ 31.7$\%$) than segmental RS(M:F 41.4$\%$ .58.5$\%$)(P<0.05). Vesicoureteral reflux(VUR) was found in 92.7$\%$(38/41) of 4he atrophic RS, which was significantly higher than 53.7$\%$(22/41) of segmental RS(P<0.05). In children without VUR, the male to female ratio did not differ between atrophic RS and segmental RS(P>0.05) But in children with VUR, there was a higher proportion of males with severe atrophic RS than segmental RS($85.7\%:45.5\%$) ACE gene polymorphism did not differ between the atrophic and segmental RS groups, irrespective of the presence of VUR(P>0.05). Conclusion : Most atrophic RSs were congenital which could not be preventable postnatally and the major risk factors were VUR and the male gender. ACE gene polymorphism was not the significant risk factor for an atrophic RS. (J Korean Soc Pedialr Nephrol 2005;9:193-200)