Comparison of 99mTc-DMSA Renal Scan and Power Doppler Ultrasonography for the Detection of Acute Pyelonephritis and Vesicoureteral Reflux

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.

Daño renal cortical en niños con primera infección del tracto urinario alto / Cortical renal damage in children with a first infection of the high urinary tract

Introducción: entre el 5 y 22 % de los niños que padecen pielonefritis aguda desarrollarán cicatriz renal. Objetivo: describir los aspectos clínico-epidemiológicos del daño renal cortical en niños con la primera infección del tracto urinario alto. Métodos: estudio observacional prospectivo y longitudinal sobre el daño renal cicatricial en niños con la primera infección urinaria alta, ingresados en el servicio de nefrología del Hospital Pediátrico Universitario "William Soler", entre el 1º de enero de 2008 y diciembre 31 de 2009. Se diagnosticaron 50 pacientes, y 38 reunieron criterios para incluirlos en el estudio. Los pacientes tenían una edad media de 18 meses. A los 38 pacientes se les realizó ultrasonido renal durante la fase aguda de la enfermedad, y gammagrafía renal estática entre 6 y 12 meses después del cuadro agudo, para precisar la lesión renal cortical. En los casos con cicatriz renal, ausencia o disminución de captación del radiofármaco (99mTc-DMSA), se les realizó uretrocistografía miccional para precisar la existencia de reflujo vesicoureteral. Resultados: 28 pacientes (73,7 %) son del sexo femenino, 17 (44,7 %) menores de 6 meses, 17 (44,7 %) tienen entre 6 y 36 meses, y 4 (10,6 %) > 3 años. La infección urinaria fue atípica en 23 (60,5 %), y el germen aislado, la Escherichia coli en 33 (86,8 %). El ultrasonido de la fase aguda demostró dilatación pélvica renal en 3 (7,9 %) y asimetría renal en 1 (2,6 %). En 2 pacientes (5,2 %) se demostró cicatriz renal y en 11 (28,4 %) hipofunción de la corteza renal. La uretrocistografía miccional demostró reflujo vesicoureteral grado III en una niña, que además, tenía cicatriz renal. No existió relación entre el inicio de los síntomas, comienzo de la terapeútica y lesión cortical. Conclusiones: los factores de riesgo para desarrollar cicatriz renal pospielonefrítica fueron: sexo femenino, edad menor de 3 años y reflujo vesicoureteral grado III.

Introduction: between the 5 and the 22 % of children suffering acute pyelonephritis will develop a renal scar. Objective: to describe the clinical-epidemiological features of the cortical renal damage in children with a first infection of high urinary tract. Methods: a longitudinal, prospective and observational study was conducted on the cicatricial renal damage admitted in the Nephrology services of the "William Soler" University Children Hospital from January 1, 2008 to December 31, 2009. Fifty patients were diagnosed and 38 fulfilled the inclusion criteria to study. Patients had a mean age of 18 months and underwent renal ultrasound during the acute phase of disease and static renal scintigraphy between 6 and 12 months after the acute picture, to specify exactly the cortical renal injury. In cases of renal scar, lack or decrease of the radioactive drug capture (99mTc-DMSA) authors carried out miction uretrocystography to specify exactly the presence of vesicoureteral reflux. Results: twenty six patients (73.7 %) are females, 17 (44.7 %) aged under 6 months, 17 (44.7 %) have between 6 and 36 months and 4 (10.6 %) > 3 years old. The urinary infection was atypical in 23 (60.5 %) and as a isolated germ the Escherichia coli in 33 (86.8 %). Ultrasound of acute phase demonstrated a renal pelvis dilation in 3 (7.9 %) and renal asymmetry in 1 (2.6 %). In 2 patients (5.2 %) there was renal scar and in 11 (28.4 %) an decreased function of the renal cortex. The miction uretrocystography demonstrated the presence of grade III vesicoureteral reflux in a girl, who also had a renal scar. There was not relation between the onset of symptoms, the onset of therapeutics and the cortical injury. Conclusions: the risk factors to develop a post-pyelonephritis renal scar were: female sex, be aged under 3 and grade III vesicoureteral reflux.

Función renal relativa normalizada por volumen en la gamagrafía con 99mTc-DMSA: estudio basado en una población pediátrica / Volume normalized relative renal function in 99mTc-DMSA scintigraphy: study in a paediatric population

Objetivo Evaluar las diferentes características diagnósticas de la función renal relativa (FRR) y de la función renal relativa normalizada por volumen renal relativo (FRRN), con el fin de analizar la posible mejora diagnóstica que implicaría su uso conjunto. Métodos Hemos estudiado con 99mTc-DMSA 952 unidades renales (riñones individuales), que pertenecían a 476 pacientes pediátricos (269 niñas) de edades comprendidas entre 0 y 11 años. De ellas, 355 unidades renales se consideraron patológicas a partir del análisis visual gammagráfico. Se determinaron los puntos de corte más apropiados para establecer los valores normales de las funciones FRR y FRRN, considerando como patrón de referencia al análisis visual gammagráfico. Se realizaron curvas ROC y se calculó el índice “J de Youden” y la exactitud para diferentes puntos de corte desde 42 por ciento hasta 50 por ciento, tanto para la FRR como para la FRRN. Se realizó también un análisis bayesiano (global y parcial clasificando las unidades renales por indicaciones clínicas) de la FRR y la FRRN. Resultados Para la FRR el mejor punto de corte fue 45 por ciento y para la FRRN fue 47 por ciento. El análisis bayesiano global mostró mejores resultados de los diferentes parámetros estadísticos para la FRRN. El análisis bayesiano parcial indicaba un importante incremento de la sensibilidad en pacientes con patología de dilatación de vía: de 10 por ciento (FRR) a 74.6 por ciento (FRRN); y con pielonefritis aguda: de 29.2 por ciento (FRR) a 66.2 por ciento (FRRN) mientras que en pacientes con nefropatías crónicas la sensibilidad fue similar (70.1 por ciento). Conclusión El cálculo de la FRRN (punto de corte 47 por ciento) proporciona información útil y complementaria a la FRR, ya que cuantifica la calidad relativa del riñón independientemente del volumen renal y refleja mejor los hallazgos gammagráficos.

Purpose To assess the different diagnostic features of relative renal function (RRF) and volume normalized relative renal function (NRRF) with the aim of analysing the possible diagnostic improvement that would imply their joint use. Methods We studied 952 kidneys with 99mTc-DMSA, belonging to 476 paediatric patients (269 girls) aged 0-11 years. 355 out of total were considered pathologic (visual analysis). The most appropriate cut-off points for establishing normality of RRF and NRRF were determined, considering as gold standard the visual scintigraphic analysis. R.O.C. curves were performed, J Youden index and accuracy were calculated for the different cut-off points from 42 percent to 50 percent for RRF and NRRF. A bayesian analysis (global and partial according to clinical indications) of RRF and NRRF was also performed. Results For RRF the better cut-off point was 45 percent and for NRRF 47 percent. The global bayesian analysis showed better values of the different statistical parameters for NRRF. Partial bayesian analysis indicated an important increment of sensitivity in patients with dilated pyelocalicial system: from 10 percent (RRF) to 74.6 percent (NRRF); and acute pyelonephritis: from 29.2 percent (RRF) to 66.2 percent (NRRF) while the sensitivity in patients with chronic nephropathy remained stable (70.1 percent). Conclusion NRRF calculation (cut-off 47 percent) provides useful and additional information to RRF, as it quantifies the relative quality of kidney tissue regardless of renal volume and better reflects better the scintigraphic findings.

Prevalence of Vesicoureteral Reflux According to the Timing of Voiding Cystourethrography in Infantile Urinary Tract Infection

PURPOSE: To evaluate the prevalence of vesicoureteral reflux (VUR) according to the timing of voiding cystourethrography (VCUG) in infantile urinary tract infection (UTI). METHODS: The data of 134 infants (1-12 months) with renal cortical defect in 99mTc-2, 3-dimercaptosuccinic acid (99mTc-DMSA) scan with a diagnosis of UTI in two hospitals from 2000 to 2010 were retrospectively analyzed. The VCUG was performed after 2 weeks from the diagnosis of UTI in Group I (n=68), and the VCUG was performed within 2 weeks from the diagnosis of UTI in Group II (n=66). RESULTS: There were no significant differences between the two groups in the duration of fever, white blood cell count, C-reactive protein levels, and abnormalities in ultrasonography (P>0.05). There was no significant difference between the two groups in the prevelence of VUR, bilateral VUR, and severe VUR. VCUG-induced UTI was detected 16 (23.5%) of patients in whom the procedure was performed 2 weeks after the diagnosis, and none of VCUG-induced UTI occurred in those in whom the procedure was performed 2 weeks within the diagnosis. CONCLUSION: We conclude that the prevalence of VUR according to the timing of VCUG did not differ between the two groups in infantile UTI with renal cortical defect in DMSA scan. We also found that performing VCUG with antibiotics can decrease risk of VCUG-induced UTI.

Prognostic Factors of Renal Defects on the Initial DMSA Scan in Children with Acute Pyelonephritis

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 99mTc-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 follow-up 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.

Limitations of 99mTc-DMSA scan in diagnosing acute pyelonephritis in children / 소아과

PURPOSE: We aimed to prove the relative limitation of 99mTc-DMSA scintigraphy (DMSA) compared to computed tomography (CT) in diagnosing acute pyelonephritis (APN) in children. METHODS: Since September 2006, after a 64-channel CT was imported, 10 DMSA false-negative patients have been identified: these patients underwent a CT scan for acute abdomen or acute febrile symptoms and were diagnosed as having APN; however, their DMSA scans were clear. We focused on these 10 DMSA false-negative patients and analyzed their clinical findings and CT results. We used Philips Brilliance Power 64-channel CT scanner for the CT scan and Siemens Orbitor Nuclear Camera 60 Hz for the DMSA scan. RESULTS: The 10 DMSA false-negative patients were mostly males (80%) and infants (80%). They had fever for a mean of 1.1-day duration before admission and showed increase in acute reactants: leukocyte, erythrocyte sedimentation rate, and C-reactive protein. The CT findings of renal lesions were focal in 6 (60%) cases and diffuse in 4 (40%) cases, and most of the lesions were unilateral in 80% of patients. CT proved that 22 renal lesions were neglected by DMSA. Differential renal function test by DMSA was also of no use in the evaluation of renal lesions. CONCLUSION: In this study, DMSA scan showed limitation in finding renal cortical lesions of CT-proven APN patients. DMSA false-negative results seem to occur at early-phase disease of infantile age, but more prospective studies are needed to determine the reasons and their prevalence.

Estimation of absolute renal uptake with technetium-99m dimercaptosuccinic acid: direct comparison with the radioactivity of nephrectomy specimens / Estimativa da captação renal absoluta com ácido dimercaptosuccínico marcado com tecnécio-99m: comparação direta com a radioatividade medida em peças de nefrectomi

CONTEXT AND OBJECTIVE: Studies using radionuclides are the most appropriate method for estimating renal function. Dimercaptosuccinic acid chelate labeled with technetium-99m (99mTc-DMSA) is the radiopharmaceutical of choice for high-resolution imaging of the renal cortex and estimation of the functional renal mass. The aim of this study was to evaluate a simplified method for determining the absolute renal uptake (ARU) of 99mTc-DMSA prior to nephrectomy, using the radioactivity counts of nephrectomy specimens as the gold standard. DESIGN AND SETTING: Prospective study at the Division of Nuclear Medicine, Department of Radiology, Universidade Estadual de Campinas. METHODS: Seventeen patients (12 females; range 22-82 years old; mean age 50.8 years old) underwent nephrectomy for various reasons. Renal scintigraphy was performed three to four hours after intravenous administration of a mean dose of 188.7 MBq (5.1 mCi) of 99mTc-DMSA, which was done six to 24 hours before surgery. The in vivo renal uptake of 99mTc-DMSA was determined using the radioactivity of the syringe before the injection (measured using a dose calibrator) and the images of the syringe and kidneys, obtained from a scintillation camera. After surgery, the reference value for renal uptake of 99mTc-DMSA was determined by measuring the radioactivity of the nephrectomy specimen using the same dose calibrator. RESULTS: The ARU measurements were very similar to those obtained using the reference method, as determined by linear regression (r-squared = 0.96). CONCLUSION: ARU estimation using the proposed method before nephrectomy seems to be accurate and feasible for routine use.

CONTEXTO E OBJETIVO: Os estudos com radionuclídeos são os mais adequados para se estimar a função renal. O ácido dimercaptosuccínico marcado com tecnécio-99m (DMSA-99mTc) é o radiofármaco de escolha para imagens de alta resolução dos rins, permitindo, também, estimar massa de parênquima renal funcionante. O objetivo deste estudo foi avaliar um método mais simples para determinar-se a captação renal absoluta (CRA) de DMSA-99mTc antes de nefrectomias e validá-lo utilizando-se as contagens radioativas das próprias peças de nefrectomia como padrão-ouro. TIPO DE ESTUDO E LOCAL: Estudo prospectivo, desenvolvido no Serviço de Medicina Nuclear do Departamento de Radiologia da Universidade Estadual de Campinas. MÉTODOS: Foram estudados 17 pacientes (12 pacientes do sexo feminino, média de idade de 50,8 anos), selecionados para a realização de nefrectomia. A cintilografia renal foi realizada três a quatro horas após a administração venosa de 188,7 MBq de DMSA-99mTc, seis a 24 horas antes da cirurgia. A CRA in vivo foi determinada utilizando-se a radioatividade da seringa antes da injeção (medida com um calibrador de dose) e as imagens da seringa e dos rins, obtidas em uma câmara de cintilação. Após a cirurgia, o valor de referência para a CRA foi determinado medindo-se a radioatividade da peça de nefrectomia com o mesmo calibrador de dose. RESULTADOS: Os valores de CRA foram muito semelhantes àqueles obtidos com o método de referência, conforme foi demonstrado pela análise de regressão linear (r-quadrado = 0,96). CONCLUSÃO: A estimativa da CRA com o método proposto antes de nefrectomiasparece ser acurado e aplicável ao uso rotineiro.

Risk Factors of Renal Scar After Acute Pyelonephritis in Children

PURPOSE: In this study we re-evaluated the known risk factors of pyelonephritic scarring in children. METHODS: A prospective study was performed on 36 acute pyelonephritis(APN) patients who were diagnosed as first acute pyelonephritis on 99mTc-DMSA scan between September 1998 and March 2000 in Masan Samsung Hospital. According to the prescence of remnant lesions on the 99mTc-DMSA scan performed 6 months after the first 99mTc-DMSA scan, the patients were divided into scar(Group A, N=15) and non-scar groups(Group B, N=21). We compared known risk factors of renal scarring between the two groups. RESULTS: There were no differences in age, sex, cultured organisms and CRP level between the two groups. Most of the initial 99mTc-DMSA scan results were not different but bilateral multiple lesions were much more common in group A(40.0% of Group A patients) compared with group B (9.5% of Group B patients). Moderate to high grade vesicoureteral reflux was also much more commonly observed in group A(46.6% of Group A patients) compared with group B(4.8% of Group B patients). CONCLUSION: Bilateral multiple lesion on initial 99mTc-DMSA scan and moderate to high grade vesicoureteral reflux at diagnosis of acute pyelonephritis may be risk factors associated with renal scarring after acute pyelonephritis in children.

The Diagnostic Value of 99mTc DMSA Renal Scan SPECT Images in Addition to Planar Image in Children with Urinary Tract Infection

PURPOSE : 99mTc DMSA renal scan have been widely used not only for the evaluation of renal scars but also for the diagnosis of acute pyelonephritis. Recent studies have shown SPECT images have higher accuracy than the planar images with some controversy. We evaluated the availability of the SPECT images adding to planar images for the diagnosis of acute pyelonephritis(APN) and renal scar in children with urinary tract infection (UTI). METHODS : 130 children with UTI (260 kidney units) and 22 follow-up children (44 kidney units) were included between January 1, 1997 and July 31, 1999 at Ewha University Mokdong Hospital. Planar Anterior and posterior images and SPECT axial and coronal images of 99mTc DMSA renal scan were obtained with Starcam 4000-i U.S.A. GE at 3 hours after 99mTc DMSA I.V. injection. The data were analyzed by Chi square test after Yates's correction. RESULTS : The detection rate of the acute pyelonephritis by SPECT images was 12.3% higher than that of planar images (47.7% vs 35.4%) by the patient and 6.9% higher also (31.9% vs 25.4%) by the kidney unit. 18 kidney units with negative planar images had focal defect in 10 kidney units (3.8%) and multifocal defect in 8 kidney units (3.1%) on SPECT images, but 1 kidney unit with positive planar image had negative SPECT image. SPECT images were superior to the planar images in 17.3%, identical in 82.3% and inferior in 0.4% to planar image. The detection rate of the renal scars by SPECT images was 13.7% higher than planar images by the patient (68.2% vs 54.5%) and 6.8% higher also (43.2% vs 36.4%) by the kidney unit. SPECT images were superior to the planar images in 17.3% and identical in 82.3% to planar image. CONCLUSION : SPECT images had shown higher detection rate and better image than planar images for the diagnosis of the acute pyelonephritis and the evaluation of the renal scars.

The Efficacy of 99mTc-DMSA SPECT in Diagnosis of Renal Scarringn of Vesicoureteral Reflux in Children / 대한비뇨기과학회지

PURPOSE: The diagnosis of renal scarring is very important for the pediatric patient because it has been associated with the later development of hypertension, renal failure, and end-stage kidney disease. Recent studies indicate that the sensitivity and specificity of the99mTc-DMSA single photon emission computerized tomography (SPECT) is better than IVP, USG, and 99mTC-DMSA Planar ThG Purpose Of this Study iS tO Compare 2 types Of 9%nTh DMSA renal scan(planar and SPECT) and IVP/USG in the diagnosis of renal scars. MATERIALS AND METHOD: We reviewed retrospectively the data of 49 children(72 renal units) with vesicoureteral reflux(VUR) who underwent renal cortical imaging with IVP/USG from January 1987 to August 1996. Patient ages ranged from 3 months to 14 years with a mean age 3.7 years. There were 17 boys and 12 girls(44 venal units) with 99mTc-DMSA planar with IVP/USG, and 12 boys and 8 girls(28 renal units) with 99mTc-DMSA SPECT with IVP/USG. RESULTS: The 99mTc-DMSA planar imaging identified 94.7% sensitivities while 99mTC-DMSA SPECT imaging identified 96.3% Sensitivities. And the IVP/USG identified 75.3% sensitivities. CONCLUSIONS: Recently, the 99mTc-DMSA renal scan has replaced IVP/USG in detecting renal scarring. And we show that 99mTc-DMSA SPECT studies are superior to IVP/USG, 99mTc-DMSA planar studies in detecting renal scarring. We believe that the role of 99mTc-DMSA SPECT will become increasingly important in detecting renal scarring of VUR.

Diagnostic Value of 99mTc-DMSA SPECT in Children with Urinary Tract Infection

PURPOSE: The accurate identification of renal cortical defects in children with urinary tract infection is essential in reducing subsequent morbidity. Imaging of the kidneys with 99mTc-dimercaptosuccinic acid (DMSA) has been demonstrated as the sensitive method available for identification of renal cortical defects. Single photon emission computerized tomography (SPECT) has been suggested as a method by which the accuracy of identification of renal cortical defects can be improved. The aim of this study was to assess the diagnostic value of the 99mTc-DMSA SPECT, comparing the detection rate of cortical defects identified from planar imaging and SPECT data. METHODS: 99mTc-DMSA SPECT, planar imaging and voiding cystourethrogram (VCUG) were performed in 76 patients diagnosed urinary tract infection at the department of pediatrics, Kyung Hee University Hospital, from March, 1994 to Feburary, 1995. Follow-up 99mTc-DMSA SPECT was done in 7 patients. RESULTS: 1) Overall detection rate of 99mTc-DMSA SPECT imaging was 32.9% (25/76), but, planar imaging showed cortical defects in 21.1% (16/76). 2) The patients with renal cortical defects in planar imaging showed all definite or more additional cortical defects in 99mTc-DMSA SPECT imaging. 3) Seven patients presented improvement in 4, no change in 2, and aggrevation in 1 on follow-up studies. 4) Incidence of renal cortical defects was higher in patients with vesicoureteral reflux (VUR); the detection rate was 83.3% (10/12). But, those of without VUR also presented high detection rate as 23.4% (19/60). 5) There is no correlation between renal cortical defects and urine culture findings. CONCLUSIONS: 99mTc-DMSA SPECT imaging is superior to planar imaging, thus 99mTc-DMSA SPECT is a useful initial diagnostic tool in children suggesting urinary tract infection, irrespective of VUR, to identify patients who need more extensive radiological studies and early treatment.

Diagnostic Value of 99mTc-DMSA Renal Scan for Early Diagnosis of Acute Pyelonephritis in Children with Febrile Urinary Tract Infection

PURPOSE: For prevention of renal scar, early diagnosis and treatement of acute pyelonephritis are important in children with febrile urinary tract infection. But it has been difficult to differentiate acute pyelonephritis from lower urinary tract infection. We have performed this study to evaluate the diagnostic value of 99mTc-DMSA renal scan and to clarify the relationship among acute pyelonephritis, vesico-ureteral reflux and renal scar. METHODS: We have studied 100 patients with febrile urinary tract infection, from September, 1993 to June, 1995 at the Pediatric department of Ewha Womans University, Mok-dong hospital. Acute phase reactants, causative organism, renal ultrasound, 99mTc- DMSA renal scan on the acute stage, voiding cystouretherogram after 1-2 weeks of treatement, and follow-up 99mTc-DMSA renal scan were evaluated. RESULTS: Ther results are as follows; 1) 57 patients (57%) had defect on 99mTc-DMSA renal scan and diagnosed as acute pyelonephritis. 2) Acute phase reactants, renal ultrasound had low accuracy. 3) VUR was found in 31 (56.1%) of 57 patients with defect which was significantly higher than the 4 (9.3%) of 43 patients without defect on 99mTc-DMSA renal scan. 4) On the follow up 99mTc-DMSA renal scan, 34.8% of defects recorvered, and 65.2% of defects developed renal scar. CONCLUSIONS: 99mTc-DMSA renal scan is a valuable method for early diagnosis of acute pyelonephritis in children with febrile urinary tract infection. It would contribute to evaluate the relationship between acute pyelonephritis, vesico-ureteral reflux and renal scar.

Evaluation of the renal function using 99mTc dimercaptosuccinic acid (DMSA) / 대한비뇨기과학회지

99mTc-DMSA is a new renal scanning agent that provides a good quality of renal image as a result of preferential cortical accumulation and also makes feasible a quantitative assessment of separate kidney functions. Using 99mTc-DMSA renal scan. we evaluated renal functions in 26 patients who had unilateral non-functioning obstructed kidneys on intravenous pyelogram (IVP) and normal contralateral kidneys for recent 2 years and decided whether to perform surgeries for relief of obstructions or nephrectomies. In the patients who undertook surgeries for relief of obstructions for the recovery of renal functions, we compared renal functions of preoperative and postoperative obstructed kidneys. The results were as follows: 1. Etiologic diseases in 26 patients were urinary stones in 13. ureteropelvic junction obstructions in 7 and renal tuberculosis in 6. 2. Nephrectomies were performed in 13 patients who showed less than 15% of the total renal functions as determined by a preoperative 99mTc-DMSA scans. 3. Surgeries for relief of obstructions were performed in the other 13 patients for the recovery of the renal functions. The functions of the obstructed kidneys as determined by preoperative 99m Tc-DMSA scans were from 23% to 42% (mean 29.3%) and by postoperative 99mTc-DMSA scans were from 24% to 47 % (mean 34.4 %). The functions of the obstructed kidneys were recovered from 1% to 12% (mean 43.5 %) after surgeries for relief of obstructions. The follow-up periods were from 1 to 13 months (mean 6.6 month).