Value of the Filtration Fraction Assessed by Dynamic ⁹⁹mTc-Diethylenetriaminepentaacetic Acid Renal Scintigraphy After Angiotensin-Converting Enzyme Inhibition for the Diagnosis of Renovascular Hypertension / 대한핵의학회잡지

PURPOSE: This study aimed to determine the diagnostic value of the relative filtration fraction (RFF) assessed by dynamic ⁹⁹mTc-diethylenetriaminepentaacetic acid (⁹⁹mTc-DTPA) renal scintigraphy after angiotensin-converting enzyme (ACE) inhibition for renovascular hypertension (RVHT) diagnosis.METHODS: ⁹⁹mTc-DTPA captopril renal scintigraphy performed in adolescents or adults (≥ 10 years) with suspected RVHT was retrospectively reviewed. The RFF of the affected kidney was qualitatively assessed as the relative glomerular filtration rate during the 2 to 3-min period compared with the relative perfusion during the first 60 s (qualitative RFF) and scored from 1 (definitely same) to 5 (definitely decreased). The quantitative RFF of the affected kidney was obtained by dividing the percentage of glomerular filtration rate by the percentage of renal perfusion.RESULTS: Overall, 173 patients (high probability, n = 15; and low probability, n = 158) were included based on conventional captopril renal scintigraphic criteria. An abnormal qualitative RFF was observed in 12 patients with high probability, and the diagnostic sensitivity was 80.0% (95% CI, 51.9–95.7). The RFF was normal in 152 patients with low probability, and the diagnostic specificity was 96.2% (95% CI, 91.9–98.6). The RFF was lower in patients with high probability than in those with low probability (0.79 ± 0.15 vs. 1.02 ± 0.11, P < 0.0001).CONCLUSIONS: The RFF assessed by dynamic ⁹⁹mTc-DTPA renal scintigraphy after ACE inhibition can detect patients with high probability for RVHT. The RFF after ACE inhibition might be a useful diagnostic criterion especially when baseline scintigraphy is not available for evaluating ACE inhibition-induced changes.

Nuclear Imaging in Pediatric Kidney Diseases

Renal scintigraphy is a useful tool in diagnosis and management of various nephro-urological conditions. Tc-99m dimercaptosuccinicacid renal scintigraphy (Tc-99m-DMSA), Tc-99m mercaptoacetyltriglycine (Tc-99m-MAG3) or Tc-99m diethylenetriaminepentaaceticacid (Tc-99m-DTPA) dynamic renal scintigraphy, and Radionuclide micturating cystography are the common scans used in children withkidney diseases. These studies are minimally invasive, easily available, and offer both anatomic details and functional informationrequired for thorough evaluation. At the same time, it is essential to have appropriate knowledge to interpret these studies and be awareof their limitations and pitfalls. The advent of Positron emission tomography-computed tomography/magnetic resonance imaging (PET-CT/MRI) has broadened the scope of nuclear medicine. This article focuses on the technique, interpretation, indication and recentpractice guidelines of renal scintigraphy in children with kidney diseases.

Incidencia de pielonefritis aguda en menores de 5 años hospitalizados con urocultivo positivo / Incidence of Acute Pyelonephritis in Hospitalized Children under 5 Years Old with Positive Urine Culture

Introducción: la infección de las vías urinarias es una causa importante de morbilidad infantil. Establecer si existe pielonefritis aguda es un factor importante para su tratamiento. Materiales y métodos: estudio observacional descriptivo. Se registraron los resultados de uroanálisis, gram de orina y urocultivo de niños entre 3 meses y 5 años de edad hospitalizados con sospecha de infección de las vías urinarias, entre enero de 2008 y diciembre de 2010. En pacientes con urocultivo positivo se evaluó el resultado de la gammagrafía renal, estimando la incidencia de pielonefritis aguda. Resultados: se recolectaron 1.463 historias clínicas y se solicitó urocultivo en 237. De estas, el 54,4% fueron positivas para pielonefritis. En 93 casos se tomaron gammagrafías renales, positivas en el 59,1% de los casos. Conclusiones: la incidencia de pielonefritis aguda en pacientes con infección de las vías urinarias se confirmó en el 59,1%.

Introduction: Urinary tract infection is a major cause of child morbidity. The diagnosis of acute pyelonephritis is important to decide the treatment. Methods: Retrospective observational study. We collected information of urinalysis, urine Gram and urine culture of hospitalized children between 3 months and 5 years old, with suspected urinary tract infection between January 2008 and December 2010. In patients with positive urine culture, the results of renal scintigraphy (Gamma scan) were evaluated to estimate the incidence of acute pyelonephritis. Results: We identified 1,463 medical records. Urinary culture was obtained in 237 patients, of whom 54.4% were positive. Renal scintigraphy was obtained in 93 of these patients and 59.1% were positive. Conclusions: The incidence of acute pyelonephritis in patients with confirmed urinary tract infection was 59.1%.

Influence of bladder fullness on the detection of urinary tract obstruction by dynamic renal scintigraphy / Influência da repleção vesical na pesquisa de obstrução do trato urinário utilizando cintilografia renal dinâmica

Abstract Objective: To investigate the influence of bladder fullness on the diagnosis of urinary tract obstruction during dynamic renal scintigraphy with a diuretic stimulator. Materials and methods: We studied 82 kidneys in 82 patients submitted to dynamic renal scintigraphy with a diuretic stimulator. We compared the proportional elimination of the radiopharmaceutical 99mTc-DTPA from the kidneys before and after bladder emptying in post-diuretic images, classifying each image as representing an obstructed, indeterminate, or unobstructed kidney. Results: The overall elimination of 99mTc-DTPA from the kidneys was 10.4% greater after bladder emptying than before. When the analysis was performed with a full bladder, we classified 40 kidneys as obstructed, 16 as indeterminate, and 26 as unobstructed. When the 40 kidneys classified as obstructed were analyzed after voiding, 11 were reclassified as indeterminate and 3 were reclassified as unobstructed. Of the 16 kidneys classified as indeterminate on the full-bladder images, 13 were reclassified as unobstructed after voiding. Conclusion: In dynamic renal scintigraphy with a diuretic stimulator, it is important to obtain images after voiding, in order to perform a reliable analysis of the proportional excretion of 99mTc-DTPA from the kidneys, avoiding possible false-positive results for urinary tract obstruction.

Resumo Objetivo: Verificar a influência da repleção vesical no diagnóstico da obstrução do trato urinário durante a cintilografia renal dinâmica com estímulo de diurético. Materiais e métodos: Foram estudados, retrospectivamente, 82 rins de 82 pacientes submetidos a cintilografia renal dinâmica. Compararam-se as porcentagens de excreção do radiofármaco DTPA-99mTc pelos rins antes e após o esvaziamento vesical nas imagens pós-diurético, classificando-os como obstruídos, indeterminados ou não obstruídos. Resultados: A avaliação da excreção do radiofármaco pelos rins mostrou que houve aumento de 10,4% na taxa de excreção global quando a bexiga foi esvaziada. Dos 82 rins estudados, 40 foram considerados obstruídos, 16 indeterminados e 26 como não obstruídos, na análise com a bexiga repleta. Na análise das imagens após micção, dos 40 classificados como obstruídos, 11 passaram a ser classificados como indeterminados e 3 como não obstruídos. Além disso, dos 16 rins apontados como indeterminados nas imagens com a bexiga repleta, 13 passaram a ser considerados não obstruídos com a bexiga vazia. Conclusão: É fundamental uma imagem após a micção na cintilografia renal dinâmica para uma análise fidedigna da porcentagem de excreção do radiofármaco pelo rim, evitando-se possíveis falso-positivos para obstrução do trato urinário.

Nuclear Medicine in Pediatric Urology

Renal scintigraphic methods, which are physiologic and minimally invasive, have played important role in the management of various renal diseases in children, providing sensitive tool for early detection of disease even before structural changes become prominent and giving valuable functional and anatomical information to aid medical decision makings in the treatment and follow-up of patients. This review article focuses on the concept and advantages of renal scintigraphy in pediatric patients with various urologic diseases.

Nuclear Medicine in Pediatric Urology

Renal scintigraphic methods, which are physiologic and minimally invasive, have played important role in the management of various renal diseases in children, providing sensitive tool for early detection of disease even before structural changes become prominent and giving valuable functional and anatomical information to aid medical decision makings in the treatment and follow-up of patients. This review article focuses on the concept and advantages of renal scintigraphy in pediatric patients with various urologic diseases.

Glomerular Filtration Rate Measurements Using 99mTechnetium-mercaptoacetyltriglycine Dynamic Renal Scintigraphy in Children with Renal Disease

PURPOSE: In children, 24-hour urine collections are unreliable for evaluating glomerular filtration rate (GFR) because of the difficulty of regulating voiding and the daily variation of urinary creatinine up to 25%. Additionally, creatinine clearance (Ccr) based on urinary creatinine is considered inaccurate. The purpose of this study was to compare estimated GFR determined using Ccr, formulas with serum cystatin C and creatinine, and 99mTc-mercaptoacetyltriglycine (MAG3) dynamic renal scintigraphy. METHODS: This retrospective study included 101 patients (age, <18 years) who visited Chung-Ang University Hospital between July 2011 and August 2012. GFR was estimated using 24-hour urinary creatinine, five formulas with serum creatinine and cystatin C, and 99mTc-MAG3 renal scan. RESULTS: Of the 101 patients, glomerular renal diseases were present in 60 patients (59.4%) and non-glomerular diseases were present in 41 patients (40.6%). There was a significant correlation between estimated GFR determined using 99mTc-MAG3 renal scan and Ccr (r=0.389, P<0.001). The correlation values between estimated GFR determined using 99mTc-MAG3 renal scan and each formula of Schwartz, Counahan-Barratt, Cockcroft-Gault, Filler and Lepage, and Bokencamp were 0.265 (P=0.007), 0.128 (P=0.044), 0.230 (P=0.021), 0.356 (P<0.001), and 0.355 (P<0.001), respectively. 99mTc-MAG3 renal scan was correlated with estimated-GFR by all formulas in decreased renal function. CONCLUSION: Estimated GFRs determined using serum creatinine and cystatin C, and 99mTc-MAG3 renal scan correlated well with estimated GFR determined using Ccr. 99mTc-MAG3 renal scan may be replaced for evaluation of renal function with convenience in patients with renal disease and decreased renal function in childhood.

Gammagrafía renal en niños con primera infección febril del tracto urinario / Renal scintigraphy in children with first febrile urinary tract infection

Introducción: la infección del tracto urinario es una de las infecciones bacterianas más frecuentes en la infancia. Objetivos: conocer las alteraciones renales en la fase aguda de la primera infección febril del tracto urinario, y relacionarlas con las variables estudiadas. Métodos: se estudiaron 211 niños con diagnóstico microbiológico de primera infección febril del tracto urinario, a los cuales se les realizó gammagrafía renal con Tc-DMSA en la fase aguda de la infección. Los resultados de la gammagrafía se correlacionaron con la duración e intensidad de la fiebre antes del diagnóstico, los reactantes de la fase aguda (hemograma, eritrosedimentación y proteína C reactiva) y los resultados de los estudios imaginológicos (ultrasonido renal y uretrocistografía miccional). Resultados: predominó el sexo femenino y el 82,4 % de los pacientes fueron menores de un año. El 54 % de los pacientes presentaron alteraciones gammagráficas, y el patrón de hipocaptación del radiofármaco fue el hallazgo que predominó en el 70 % de ellos. Se encontró asociación significativa al relacionar la duración e intensidad de la fiebre con las alteraciones renales. De los parámetros de laboratorio, la leucocitosis superior a 15 000, la eritrosedimentación acelerada y la proteína C reactiva elevada, tuvieron significación estadística con las alteraciones renales, y los hallazgos radiológicos detectados por el ultrasonido renal y uretrocistografía miccional se correlacionaron estadísticamente con la afectación renal detectada con la gammagrafía. Conclusiones: un porcentaje elevado de los pacientes presentó extensión de la infección al parénquima renal, y las variables clínicas, de laboratorio e imaginológicas estudiadas fueron parámetros orientadores de daño renal.

Introduction: the urinary tract infection is one of the most frequent bacterial infections in the childhood. Objectives: to learn about the acute renal alterations in the first febrile urinary tract infection, and to relate them to the studied variables. Methods: two hundred eleven children diagnosed as first febrile urinary tract infection patients were studied and performed Tc-DMSA renal scintigraphy in the acute phase of infection. The results were correlated to the duration and intensity of the fever before the diagnosis, to the acute phase reactants (hemogram, erythrosedimentation and reactive-C protein) and to the results of imaging studies (renal ultrasound and mictional uretrocystography). Results: females prevailed and 82.4 % of patients were under one year-old. In the study group, 54 % presented with scintigraphic alterations and the hypocapture pattern of the radiopharmaceutical was the predominant finding in 70 % of patients. There was significant association between the duration and intensity of the fever, and the renal alterations. Regarding the lab parameters, leukocytosis above 15 000, accelerated erythrosedimentation and raised reactive-C protein were statistically significant and related to the renal alterations, whereas the radiological findings observed in renal ultrasound and mictional urethrocystography were statistically correlated to the renal lesion detected in the scintigraphy. Conclusions: high percentage of patients suffered the spread of infection over the renal parenchyma; additionally the studied clinical, lab and imaging variables indicated renal injure.

Ecografía renal con Doppler en el diagnóstico de pielonefritis aguda en niños / Renal ultrasound with Doppler in the diagnosis of acute pyelonephritis in children

Objective: This study evaluates the diagnostic value of Renal Doppler Ultrasound (RDU) in the diagnosis of acute renal involvement among children admitted for a first febrile urinary tract infection (UTI), compared to a Renal Scintigraphy (RS). Methodology: All children admitted during 2009 for a first febrile UTI and positive urinary culture were prospectively studied. All received a RDU and RS with Tc99di-mercaptosuccinic acid during the first 72 hours of hospitalization. Image evaluation was performed blindly. RS was considered to be the gold standard to identify renal involvement. Results: The protocol was completed in 54 children (90 percent). RDU was altered in 36 (66 percent), and RS in 42 (78 percent) of children. Both exams coincided in 78 percent of the children, and in 81 percent of the kidneys. Sensitivity and specificity of RDU for these patients was 78,6 percent and 75 percent (72 percent and 89,6 percent per kidney), respectively. Negative predictive value was 50 percent. RDU detected significantly fewer defects in the left kidney, (p = 0,0026), especially if the defect was localized in the upper pole, and in absence of other associated scintigraphic abnormalities (p = 0,0001). Children with scintigraphic renal involvement showed significant more alterations during the acute phase. Conclusions: RDU is sensitive and specific to detect renal involvement in a child admitted for a febrile UTI, but has a low negative predictive value. Therefore, a negative ultrasound in a patient with inflammatory signs should be confirmed through a scintigraphy, since there are certain sites that are difficult to localize in a sonogram, such as the left superior pole.

Introducción: El objetivo del presente estudio fue evaluar las propiedades diagnósticas de la ecografía renal con Doppler (ERD) en la identificación del compromiso renal agudo, en una cohorte de niños hospitalizados con primera infección urinaria (ITU) febril y compararlas con el cintigrama renal estático (CR). Metodología: Durante el año 2009, en forma prospectiva, se estudiaron todos los niños hospitalizados con primera ITU febril y con urocultivo positivo. En todos ellos se realizó una ERD y un CR con ácido dimercapto succínico marcado con tecnecio 99, dentro de las primeras 72 horas de hospitalización. Los estudios de imágenes fueron realizados en forma ciega, por operadores independientes. El CR se consideró como gold standard para la identificación de compromiso renal. Resultados: En 54 niños (90 por ciento de los elegibles) hospitalizados por ITU febril se cumplió el protocolo de estudio imageneológico. La ERD estuvo alterada en 36 (66 por ciento) y el CR en 42 (78 por ciento) de los niños. Ambos exámenes fueron coincidentes en 78 por ciento de los niños y en 81 por ciento de los riñones estudiados. La sensibilidad y especificidad del la ERD para estos pacientes fueron de 78,6 por ciento y 75 por ciento (72 por ciento y 89,6 por ciento al analizarlo por unida renal), respectivamente, y el valor predictivo negativo de 50 por ciento. La ERD pesquisó significativamente menos defectos cuando éstos eran exclusivos del riñón izquierdo (p = 0,0026), especialmente si el defecto se localizó en el polo superior y en ausencia de otras alteraciones cintigráficas asociadas (p = 0,0001). Los niños con compromiso renal cintigráfico tenían significativamente más alterados los reactantes de fase aguda. Conclusiones: La ERD en un niño hospitalizado por una ITU febril tiene alta sensibilidad y especificidad para pesquisar el compromiso renal, pero un bajo valor predictivo negativo; por lo tanto, si la ERD es negativa y el paciente presenta parámetros inflamatorios alterados, el compromiso renal debe ser confirmado por un CR, ya que existe evidencia de ciertas localizaciones más difíciles de identificar por la ERD, como aquellas que afectan el polo superior izquierdo.

Hallazgos gammagráficos en niños con primera infección febril del tracto urinario / Scintigraphy findings in children presenting the first febrile infection of urinary tract

INTRODUCCIÓN. La infección del tracto urinario es una de las infecciones bacterianas más frecuentes en la infancia. El objetivo de esta investigación fue conocer las alteraciones renales en la fase aguda de la primera infección febril del tracto urinario. MÉTODOS. Se estudiaron 90 niños con diagnóstico microbiológico de primera infección febril del tracto urinario, a los cuales se les realizó gammagrafía renal con Tc DMSA en la fase aguda de la infección. Los resultados de la gammagrafía se correlacionaron con la duración e intensidad de la fiebre antes del diagnóstico, los reactantes de la fase aguda (hemograma, ritrosedimentación y proteína C reactiva [PCR]) y los resultados de los estudios radiológicos (ultrasonido renal y uretrocistografía miccional). RESULTADOS. Predominó el sexo femenino y el 84,4 por ciento de los pacientes fueron menores de 1 año. El 59 por ciento de los pacientes presentaron alteraciones gammagráficas y el patrón de hipocaptación del radiofármaco fue el hallazgo que predominó en el 75,5 por ciento de éstos. No se encontró asociación significativa al relacionar la duración e intensidad de la fiebre con las alteraciones renales. De los parámetros de laboratorio solo la PCR tuvo significación estadística con las alteraciones renales y los hallazgos radiológicos detectados por el ultrasonido renal y uretrocistografía miccional no se correlacionaron estadísticamente con la afectación renal detectada con la gammagrafía renal.CONCLUSIONES. Un porcentaje elevado de los pacientes presentó extensión de la infección al parénquima renal y la PCR fue el único parámetro orientador de daño renal

INTRODUCTION. Urinary tract infection (UTI) is one of the more frequent bacterial infections in childhood. The aim of present research was to know the acute phase renal alterations of the first febrile infection of urinary tract. METHODS. Ninety children with a microbiological diagnosis of first febrile infection of urinary tract were studied and a renal Tc DMSA scintigraphy was done in the acute phase of infection. Scintigraphy results were correlated with the fever length and intensity before diagnosis, acute phase reactants (hemogram, erythrosedimentation and C reactive protein (CRP) and the radiological studies results (renal US and urination urethrocystography). RESULTS. There was a female sex predominance and the 84,4 percent of patients were under 1 year. The 59 percent of patients had scintigraphy alterations and the radiodrug hypocaptation pattern was the predominant finding in the 75,5 percent of them. There was not a significant association between the fever length and intensity and the renal alterations. From the laboratory parameters only the RCP was statistically significant with renal alterations and the radiologic findings detected by renal US and urination urethrocystography had not statistic correlation with the renal affection detected by renal scintigraphy. CONCLUSIONS. A high percentage of patients had an extensive infection to renal parenchyma and the CRP was the only guiding parameter of renal damage

¿Es el cintigrama renal estático diferido mejor predictor de reflujo vesicoureteral que el cintigrama renal estático en etapa aguda en niños con infección urinaria febril? / Is late static renal scintigraphy a better predictor of vesicoureteral reflux than acute renal static scintigraphy? in children whit first episode of febrile urinary infection?

Objetivo: Comparar la utilidad del CRE en etapa aguda versus el CRE diferido para predecir la presencia y/o ausencia de RVU en niños con primer episodio de ITU febril. Material y métodos: Estudio retrospectivo donde se analizaron 95 pacientes con primer episodio deITU febril, a los cuales se les realizó dentro de los primeros 15 días de evolución del cuadro un CRE control y luego un CRE diferido después de 6 meses del primer episodio. Se correlacionó la presencia de alteración cintigráfica en el CRE agudo y en el CRE diferido con la existencia RVU diagnosticado mediante UCG. Resultados: La edad promedio fue de 17 meses, con 72 (75,8 por ciento) pacientes menores de 2 años de edad. Cuarenta y nueve pacientes eran de sexo femenino. Se encontró RVU en 41 de los 95 pacientes (43,2 por ciento). En la etapa aguda 93,7 por ciento de los pacientes tuvo un CRE alterado, 46,1 por ciento de los cuales tenía RVU. Ninguno de los 6 pacientes con CRE normal tuvo RVU (VPN de 100 por ciento). En el CRE diferido persistieron con alteraciones cintigráficas el 40,4 por ciento de los niños, de los cuales la mitad presentaba RVU. De los 59 niños sin alteraciones cintigráficas el 61 por ciento no tenía RVU (VPN 60 por ciento).Conclusión: El CRE diferido no es un buen predictor de RVU en niños con primer episodio de ITU febril, a diferencia del CRE realizado en etapa aguda, el cual tiene un excelente VPN para RVU.

Objective: To compare the usefulness of static renal scintigraphy done in the acute phase of febrile UTI versus late static renal scintigraphy to predicit the presence and/or absence of VUR in children with first episode of febrile UTI. Materials and methods: Retrospective study that analized 95 patients with first episode of febrile UTI, to whom a control static renal scintigraphy was done in the first 15 days of the UTI and then late static renal scintigraphy was performed after 6 months of the first episode of UTI. A correlation was made between the presence of scintigraphic abnormalities in the acute phase static renal scintigraphy and late static renal scintigraphy with the existence of VUR diagnosed by VUG. Results: The mean age was 17 months, with 72 (75.8 percent) patients younger than 2 years. Forty-nine patients were girls. VUR was found in 41 of the 95 patients (43.2 percent). In the acute phase 93.7 percent of the patients had an abnormal static renal scintigraphy, 46.1 percent of which had VUR. None of the 6 patients with a normal static renal scintigraphy had VUR (NVP de 100 percent). In the late static renal scintigraphy 40.4 percent of the patients persisted with scintigraphic alterations, the presence of VUR in this group of patients was of 50 percent. Of the 59 patients without scintigraphic abnormalities 61 percent did not have VUR (PPV 60 percent).Conclusion: The late static renal scintigraphy is not a good predictor of VUR in children with first episode of febrile UTI, unlike the static renal scintigraphy done in the acute phase of the illness, which has an excelent NPV for VUR.

GFRs Measured by Gates' Method According to 5 Background Sites: Comparison with GFR Measured by I-125-Iothalamate Method / 대한핵의학회잡지

PURPOSE: The aim was to assess how the background site affects the Gates' glomerular filtration rate (GFR) measurement using Tc-99m-DTPA in correlation with GFR by I-125-iothalamate method. MATERIAL AND METHODS: The study populations were 63 adults with 39 men and 24 women aged from 20 to 59 yrs (mean = 37.9 yrs). The following five background regions of interest were used in measurement of GFR using Gates' method: 1) lower side of each kidney (subrenal), 2) around each kidney (circumferential), 3) upper side of each kidney (suprarenal), 4) lateral side of each kidney (lateral), 5) between the two kidneys (inter-renal). We also measured GFR using I-125-iothalamate in each subject. The two studies were separated by 1 to 3 weeks. The subjects were divided into two groups by renal depth. Group 1 with renal depth> or=7cm and group 2 with renal depth or=7cm. CONCLUSION: GFRs measured with Gates' method showed higher correlation with the GFR measured by I-125-iothalamate when the regions of interest were placed over the suprarenal and inter-renal backgrounds. And GFRs measured with Gates method showed statistically significant correlation with the GFR measured by I-125-iothalamate in the group with renal depth < 7cm.

Diagnostic Criteria of 99mTc-diethylenetriaminepentaacetic acid Captopril Renal Scan for the Diagnosis of Renovascular Hypertension by Unilateral Renal Artery Stenosis / 대한핵의학회잡지

PURPOSE: We compared captopril renal scintigraphic criteria for the diagnosis of renovascular hypertension by unilateral renal artery stenosis. MATERIALS AND METHODS: The study group consisted of 24 patients (m/f =16/8, age: 39 +/- 18 years) with unilateral renal artery stenosis who underwent renal artery revascularization and captopril renal scintigraphy with 99mTc-diethylenetriaminepentaacetic acid between May 1995 and April 2004. The blood pressure response was classified as cure/improvement or failure. We evaluated captopril-induced changes in relative function (BCfun) and renogram grade (0 to 5: 0=normal, and 5=renal failure pattern without measurable uptake) (CBren) and the difference of renograms between the normal and stenotic kidney on captopril scan (CNren). RESULTS: Eight of 24 patients were cured and 11 improved and 5 patients were classified as failed revascularization. Significant predictors of a cure or improvement of blood pressure were younger age, stenosis by fibromuscular dysplasia or arteritis, BCfun, CBren and CNren. Areas under the receiver operating characteristic curve of age, BCfun, CBren and CNren were not significantly different. Positive and negative predictive values of predictors were 100% and 42% (age or= 1%) ; 92% and 75% (CBren > or= 1), and 90% and 60% (CNren > or= 1), respectively. CONCLUSION: Captopril induced changes in renal function and renogram can reliably predict hypertension response to revascularization. Renogram pattern on captopril scan can diagnose renovascular hypertension without baseline data in patients with unilateral renal artery stenosis.

Bowel Activity Caused by Free Tc-99m Pertechnetate Mimicking Urine Leaks during Tc-99m MAG3 Renal Scintigraphy / 대한핵의학회잡지

A 43-year-old woman with diabetic nephropathy underwent a Tc-99m MAG3 renal scintigraphy for the evaluation of renal function. Posterior images at 60 minutes demonstrated a migration of radiotracer activity beyond the lower pole of the left kidney, which might be incorrectly interpreted as urine leaks. However, the increased activities were moving along the bowel lumens over time. Another ring-like radioactivity was also seen in the suprasplenic region, and increased with time. These radioactivities were in the gastric fundus and gastrointestinal tract and caused by free Tc-99m pertechnetate.

Infarction of Renal Transplant with Extrarenal Excretion of Tc-99m MAG3 Demonstrated by Renal Scintigraphy / 대한핵의학회잡지

A 38-year-old woman with end stage renal disease received a living related donor-renal transplant to the right iliac fossa. She developed anuria a week later. Tc-99m MAG3 renal scintigraphy demonstrated no perfusion, uptake, or excretion of the radioactive tracer from the renal transplant. The expected area of the renal allograft appeared as a photopenic area with increased rim activity. The gallbladder and bowel activities were observed on delayed images at 24 hours. There was no blood flow within the renal artery on renal doppler examination. This case shows total absence of perfusion and function in the infarcted renal transplant with extrarenal excretion of Tc-99m MAG3 caused by acute renal artery thrombosis.

Development of Formulas for the Estimation of Renal Depth and Application in the Measurement of Glomerular Filtration Rate in Koreans / 대한핵의학회잡지

PURPOSE: There is no established formula for estimating renal depths in Korean. As a result, we undertook this study to develop a new formula, and to apply this formula in the calculation of glomerular filtration rate (GFR). MATERIALS AND METHODS: We measured the renal depth (RD) on the abdominal CT obtained in 300 adults (M:F=167:133, mean age 50.9 years) without known renal diseases. The RDs measured by CT were compared with the estimated RDs based on the Tonnesen and Taylor equations. New formulas were derived from the measured RDs in 200 out of 300 patients based on several variables such as sex, age, weight, and height by multiple regression analysis. The RDs estimated from the new formulas were compared with the measured RDs in the remaining 100 patients as a control. In 48 patients who underwent Tc-99m DTPA renal scintigraphy, GFR was measured with three equations (new formula, Tonnesen and Taylor equations), respectively, and compared with each other. RESULTS: The mean values of the RDs measured from CT were 6.9 cm for right kidney of the men (MRK), 6.7 cm for left kidney of the men (MLK), 6.7 cm for right kidney of the women (WRK), and 6.6 cm for left kidney of the women (WLK). The RDs estimated from Tonnesen equation were shorter than the ones measured from CT significantly. The newly derived formulas were 12.813 (weight/height)+0.002 (age)+ 2.264 for MRK, 15.344 (weight/height)+0.011 (age)+0.557 for MLK, 12.936 (weight/height)+ 0.014 (age)+1.462 for WRK and 13.488 (weight/height)+0.019 (age)+0.762 for WLK. The correlation coefficients of the RD measured from CT and estimated from the new formula were 0.529 in MRK, 0.729 in MLK, 0.601 in WRK, and 0.724 in WLK, respectively. The GFRs from the new formula were significantly higher than those from the Tonnesen equation significantly, which was the most similar to normal GFR values. CONCLUSION: We generated new formulas for estimating RD in Korean from the data by CT. By adopting these formulas, we expect that GFR can be measured by the Gates method accurately in Korean.