Clinical Significance of Uptake Difference on DMSA Scintigraphy in Pediatric Urinary Tract Infection

PURPOSE: Disruption of normal renal development can lead to congenital anomalies of the kidney and urinary tract, including renal hypodysplasia. We aimed to clarify whether small kidney size affects clinical manifestations in children with urinary tract infection (UTI). METHODS: One hundred fifty-four patients who had their first symptomatic UTI between January 2014 and June 2015 were enrolled in this study. Differences in kidney size were estimated based on percent uptake of (99m)Tc-dimercaptosuccinic acid (DMSA) in scintigraphy. The patients who showed more than 10% difference in kidney size on DMSA scintigraphy with none or minimal cortical defects were included in group A. (group A, n=17). Laboratory, clinical, and imaging results were compared with those of the other patients (group B, n=137). RESULTS: Group A had a relatively higher incidence of vesicoureteral reflux than group B (44% vs 20%, P<0.05). The levels of plasma neutrophil gelatinase-associated lipocalin (NGAL) and serum C-reactive protein were significantly higher in group A (193 [64-337] vs 91 [59-211] ng/mL and 4.1 [0.5-11.9] vs 2.1 [0.7-5.3] ng/mL, respectively; all P<0.05). Linear regression analysis revealed that plasma NGAL level strongly correlated with the difference in renal uptake in DMSA scintigraphy in group A (R²=0.505). CONCLUSION: The difference in kidney size could influence the clinical course and severity of pediatric UTI.

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.

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.

Nefrolitotomía anatrófica: ¿cuánto modifica la función renal? / To what extent can anatrophic nephrolithotomy modify renal function?

El estándar de oro en el manejo de la litiasis coraliforme es la Nefrolitotomía percutánea (NLP) asociada a la Litotricia extracorpórea (LEC), sin embargo estas técnicas de elección no están disponibles en todos los centros asistenciales de nuestro país. Considerando esto y el que la evolución natural de las Litiasis Coraliformes es a la exclusión renal, es que quisimos investigar cuanto se modifica la función renal con la Nefrolitotomía Anatrófica (NLA). Pacientes y Método: Se realizó estudio descriptivo prospectivo. Entre septiembre del 2005 y febrero del 2008, 14 pacientes fueron incluidos en protocolo, que contemplaba cintigrama DMSA pre-operatorioy un control post operatorio a los 3 meses. El promedio de edad de la serie fue de 38 años (23- 59) y esta estaba constituida por 11 mujeres y 3 varones. Todos los pacientes eran portadores de Litiasis Coraliformes Grado III ó IV, fueron estudiados con pielografía de eliminación y contaban con un clearence de creatinina normal. En todos los casos se realizó isquemia fría y se utilizó ecografía intraoperatoria. Resultados: El valor promedio del cintigrama renal DMSA preoperatorio fue de 38 por ciento (23-49).El tiempo operatorio promedio fue de 123 minutos (90-150); El tiempo promedio de isquemia fría fue de 50minutos (30-80); Se presentó un caso de lesión de vena renal, la cual se suturó satisfactoriamente; 1 paciente evolucionó con infección de herida operatoria; 1 paciente quedó con una litiasis residual de 8 mm, la cual migró al uréter distal al 8 día post operatorio, con lo cual presentó filtración de orina, que se manejó con catéter doble J y a los 21 días se resolvió realizando ureterolitotomía endoscópica. El resto de los pacientes de la serie quedó libre de litiasis. El cintigrama renal DMSA de control post op. disminuyó en un promedio de 7 puntos porcentuales (2-13). Conclusión: En nuestra serie la NLA disminuyó el porcentaje de función renal cintigráfica, pero presentó bajo porcentaje...

Percutaneous nephrolithotomy (PCNL), associated with extracorporeal lithotripsy (SWL) constitutes the gold standard in the treatment of staghorn calculi. However, these techniques are not available at all health care centres in our country. Considering that the natural course of staghorn calculi leads to renal exclusion, we decided to investigate and determine to what extent anatrophic nephrolithotomy (ANL) may modify renal function. Patients and Method: We carried out a prospective and descriptive study of 14 patients; 11 women and 3 men, mean age 38 years (range 23 to 59 years), that were treated between September 2005and February 2008. Protocol included a preoperative DMSA scintigraphy and a postoperative control at 3 months following the procedure. All patients had been diagnosed with Type III or IV stag-horn calculi, had undergone an excretory pyelogram and had normal creatinine levels. Cold ischemia within tra-operative sonography was performed in all cases. Results: Mean preoperative DMSA renal function was 38 percent (23 percent to 49 percent); average operating time was 123 minutes (90 to 150 minutes); average cold ischemic time was 50 minutes (30 to 80 minutes); a renal vein lesion occurred and was repaired satisfactorily; 1 patient developed an infection in the operative incision and 1 patient had a residual 8 mm calculi which passed into the distal ureter at the 8th postoperative day, causing urine filtration that was managed with a double J catheter and was extracted at postoperative day 21 by means of an ureteroscopy. Rest of the patients were stone free.Postoperative DMSA renal function decreased in an average of 7 percent (2 percent to 13 percent). Conclusion: In our study anatrophic nephrolithotomy (ANL) reduced the percentage of scintigraphic renal function, but generated a low incidence of complications as well as a high stone free rate. Therefore, we believe that ANL is a technique that should be performed when percutaneous renal...

Usefulness of serum procalcitonin test for the diagnosis of upper urinary tract infection in children / 소아과

PURPOSE: It is difficult to make a distinction between lower urinary tract infection(UTI) and acute pyelonephritis(APN) during the acute phase of febrile UTI due to nonspecific clinical symptoms and laboratory findings, especially among young children. We measured the serum procalcitonin(PCT) in children with UTI to distinguish between acute pyelonephritis and lower UTI, and to determine the accuracy of PCT measurement compared with other inflammatory markers. METHODS: Serum samples were taken from children who admitted with unexplained fever or were suspected of having UTI. 51 children(mean 12.2+/-11.4 months) were enrolled in this study. Leukocyte counts, erythrocyte sedimentation rates(ESR) and C-reactive protein(CRP) were also measured. Renal parenchymal involvement was assessed by (99m)Tc DMSA scintigraphy in the first 7 days after admission. PCT was measured by immunoluminometric assay. RESULTS: PCT values were significantly correlated with the presence of renal defects in children with UTI(n=16)(5.06+/-12.97 microgram/L, P<0.05). However, PCT values were not significantly different between children with UTI without renal damage(n=18) and children without UTI(n=17). Using a cutoff of 0.5 microgram/L for PCT and 20 mm/hr for ESR, 20 mg/L for CRP, sensitivity and specificity in distinguishing between UTI with and without renal involvement were 81.3 percent and 88.9 percent for PCT 87.5 percent and 72.2 percent for ESR, and 87.5 percent and 55.6 percent for CRP, respectively. Positive and negative predictive values were 86.7 percent and 84.2 percent for PCT and 60.9 percent and 81.8 percent for CRP, respectively. CONCLUSION: In febrile UTI, PCT values were more specific than CRP, ESR and leukocyte count for the identification of patients who might develop renal defects.