Top-Down versus Bottom-Up Approach in Children Presenting with Urinary Tract Infection: Comparative Effectiveness Analysis Using RIVUR and CUTIE Data.

PURPOSE: The initial imaging approach to children with urinary tract infection (UTI) is controversial. Along with renal/bladder ultrasound, some advocate voiding cystourethrogram (VCUG), ie a bottom-up approach, while others advocate dimercaptosuccinic acid (DMSA) scan, ie a top-down approach. Comparison of these approaches is challenging. In the RIVUR/CUTIE trials, however, all subjects underwent both VCUG and DMSA scan. Our objective was to perform a comparative effectiveness analysis of the bottom-up vs top-down approach. MATERIALS AND METHODS: We simulated 1,000 hypothetical sets of 500 children using RIVUR/CUTIE data. In the top-down approach, patients underwent initial DMSA scan, and only those with renal scarring underwent VCUG. In the bottom-up approach, the initial study was VCUG. We assumed all children with vesicoureteral reflux (VUR) received continuous antibiotic prophylaxis (CAP). Outcomes included recurrent UTI, number of VCUGs and CAP exposure. We assumed a 25% VUR prevalence in children with initial UTI with sensitivity analysis using 40% VUR prevalence. RESULTS: Median age of the original RIVUR/CUTIE cohort was 12 months. First DMSA scan was performed at a median of 8.2 weeks (IQR 5-11.8) after the index UTI. In the simulated cohort, slightly higher yet statistically significantly recurrent UTI was associated with the top-down compared with the bottom-up approach (24.4% vs 18.0%, p=0.045). On the other hand, the bottom-up approach resulted in more VCUG (100% vs 2.4%, p <0.001). Top-down resulted in fewer CAP-exposed patients (25% vs 0.4%, p <0.001) and lower overall CAP exposure (5 vs 162 days/person, p <0.001). Sensitivity analysis was performed with 40% VUR prevalence with similar results. CONCLUSIONS: The top-down approach was associated with slightly higher recurrent UTI. Compared to the bottom-up approach, it significantly reduced the need for VCUG and CAP.

Preventive Effect of L-Carnitine on Scar Formation During Acute Pyelonephritis: A Randomized Placebo-Controlled Trial.

BACKGROUND: Urinary tract infection and pyelonephritis are clinical problems that frequently occur in children. Several factors are responsible for renal tissue injury, morbidity, and renal scarring after pyelonephritis. The aim of this study was to evaluate the preventive effect of L-carnitine on renal scarring in acute pyelonephritis. METHODS: A randomized double-blind clinical trial was conducted on 65 children aged 6 months to 10 years. Patients were randomized into 2 groups to receive 7-day treatment with only antibiotics without L-carnitine (control group; n = 32) and 7-day treatment with L-carnitine (case group; n = 33) during the acute phase of infection. Technetium-99m-labeled dimercaptosuccinic acid (DMSA) scintigraphy was performed for all children during the acute phase (in 2-7 days of hospitalization) and late phase. P-value less than 0.05 was statistically significant. RESULTS: We recruited 65 participants in the study: 32 children in control group and 33 children in case group. Three children in the control group and 2 children in the case group refused to perform the second DMSA scan. Overall, data analysis at the end of the study was done on 60 patients. Age distribution of girl patients with upper urinary infection was 6.5% in girl children aged between 6 months and 12 months, 41.1% aged between 1 and 5 years, 33.3% aged between 5 and 10 years, respectively. There was no significant difference between 2 groups in age and sex. There was no significant difference between 2 groups in systolic blood pressure, diastolic blood pressure, the lab data including urine white blood cells and serum erythrocyte sedimentation rate, and antibiogram profiles. Voiding dysfunction was detected in 10% of the participants. The baseline DMSA was not significantly difference in 2 groups, but worsening of kidney lesions was significantly higher in control group after 6 months (P = 0.012). CONCLUSION: Our study showed that L-carnitine significantly decreased renal scarring because of acute pyelonephritis.

Two-step treatment model for the adult patients with an obstructed kidney functioning below 10% of its capacity: a pilot study.

BACKGROUND: There is no written consensus as to when and in what conditions simple nephrectomy should be performed for hypo-functioning obstructed kidneys. We aimed to assess renal function and the requirement of nephrectomy in patients that underwent percutaneous nephrostomy (PCN) despite being indicated for nephrectomy due to a split renal function of less than 10% caused by ureteral obstruction. METHODS: This prospective study includes 18 patients with unilateral upper urinary tract obstruction and renal parenchymal loss on Technetium-99 m dimercaptosuccinic acid (DMSA) scintigraphy. Each patient underwent DMSA scan (DMSA-1) prior to PCN. After a 2-week follow-up period, a second DMSA scan was performed to assess renal function of each kidney (DMSA-2). Nephrectomy was performed in the kidneys functioning below 10% of their capacity, whereas kidneys functioning above 10% of their capacity were treated as appropriate to their etiologies. Renal functions and DMSA results were compared before and after nephrostomy with Paired-samples t-test and one-way ANOVA. RESULTS: Following nephrostomy, 8 (44.4%) patients had a kidney functioning above 10% of its capacity on DMSA scan and received etiology-based treatment. Glomerular filtration rates of these patients also improved significantly. A total of 9 patients who did not improve renal functions underwent nephrectomy. CONCLUSION: The results indicated that in obstructed kidneys functioning below 10% of their capacity, renal function can be recovered by using a diversion technique (such as PCN) that could alleviate the pressure within the renal pelvis and kidney parenchyma, instead of directly performing simple nephrectomy.

Unenhanced MRI as an Alternative to 99mTc-Labeled Dimercaptosuccinic Acid Scintigraphy in the Detection of Pediatric Renal Scarring.

OBJECTIVE: The purpose of this study was to determine whether unenhanced MRI without sedation is a feasible substitute for dimercaptosuccinic acid (DMSA) scintigraphy in the detection of renal scars in pediatric patients. SUBJECTS AND METHODS: Patients scheduled for 99mTc-labeled DMSA scintigraphy for assessment of possible renal scars were recruited to undergo unenhanced MRI (free-breathing fat-suppressed T2-weighted single-shot turbo spin-echo and T1-weighted gradient-echo imaging, 13 minutes' total imaging time). Scintigraphic and MRI studies were evaluated by two independent blinded specialty-based radiologists. For each imaging examination, readers identified scars in upper, middle, and lower kidney zones and rated their diagnostic confidence and the quality of each study. The scintigraphic readers' consensus score opinion for the presence of scars was considered the reference standard. RESULTS: DMSA scintigraphy showed scarring in 19 of the 78 (24.4%) evaluated zones and MRI in 18 of the 78 (23.1%). The two MRI readers found mean sensitivities of 94.7% and 89.5%, identical specificities of 100%, and diagnostic accuracies of 98.7% and 97.4%. Interobserver agreement was 98.7% for MRI and 92.3% for DMSA scintigraphy. The MRI readers were significantly more confident in determining the absence rather than the presence of scars (p = 0.02). MRI readers were more likely to rate study quality as excellent (84.6%) than were the scintigraphic readers (57.7%) (p = 0.024). CONCLUSION: Unenhanced MRI has excellent sensitivity, specificity, diagnostic accuracy, and interobserver agreement for detecting renal scars in older children who do not need sedation. It may serve as a substitute modality, especially when DMSA is not available.

Comparison of 99mTc-DMSA renal scintigraphy with biochemical and histopathological findings in animal models of acute kidney injury.

Biochemical and histological assays are currently used for the diagnosis and characterization of kidney injury. The purpose of this study was to compare technetium-99m-labeled dimercaptosuccinic acid (99mTc-DMSA) renal scintigraphy, as a non-invasive method, with common biochemical and histopathological methods in two animal models of acute kidney injury. Nephrotoxicity was induced either by gentamicin (100 mg/kg/day for one week) or unilateral ureteral ligation (UUO). Renal scintigraphy was performed 1 h after intravenous injection of 99mTc-DMSA (3 mCi). Furthermore, plasma levels of blood urea nitrogen (BUN), creatinine, sodium, and potassium were determined using an autoanalyzer. At the end of experiments, kidneys were excised for the measurement of activity uptake (mCi/gr) using a dose calibrator as well as histopathological examinations with hematoxylin and eosin (H&E) staining. There was a significant decrease in 99mTc-DMSA uptake in both gentamicin (P value = 0.049) and UUO (P value = 0.034) groups, and it was more significant in the former. The levels of BUN and creatinine increased in both gentamicin and UUO groups, while the levels of sodium and potassium remained unchanged. Furthermore, a strong correlation was found between DMSA uptake and histopathological findings. Scintigraphy with 99mTc-DMSA is capable of detection of kidney injury in both gentamicin and UUO groups. Moreover, a significant correlation was found between scintigraphy parameters and histopathological findings. This suggests 99mTc-DMSA as a non-invasive method for the evaluation of kidney injury induced by drugs or anatomical disorders.

Urinary tract infection in small children: the evolution of renal damage over time.

BACKGROUND: Our objective was to analyze the evolution of kidney damage over time in small children with urinary tract infection (UTI) and factors associated with progression of renal damage. METHODS: From a cohort of 1003 children <2 years of age with first-time UTI, a retrospective analysis of 103 children was done. Children were selected because of renal damage at index 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy at least 3 months after UTI, and a late DMSA scan was performed after at least 2 years. Damage was classified as progression when there was a decline in differential renal function (DRF) by ≥4%, as regression when there was complete or partial resolution of uptake defects. RESULTS: Of 103 children, 20 showed progression, 20 regression, and 63 remained unchanged. There were no differences between groups regarding gender or age. In the progression group, 16/20 (80%) children had vesicoureteral reflux (VUR) grade III-V and 13 (65%) had recurrent UTI. In multivariable regression analysis, both VUR grade III-V and recurrent UTI were associated with progression. In the regression group, 16/20 (80%) had no VUR or grade I-II, and two (10%) had recurrent UTI. CONCLUSIONS: Most small children with febrile UTI do not develop renal damage and if they do the majority remain unchanged or regress over time. However, up to one-fifth of children with renal damage diagnosed after UTI are at risk of renal deterioration. These children are characterized by the presence of VUR grades III-V and recurrent febrile UTI and may benefit from follow-up.

Simple renal cyst and renal dysfunction: A pilot study using dimercaptosuccinic acid renal Scan.

AIM: Little is known about the association between renal cyst and renal dysfunction. We evaluated the deterioration of renal function in patients with unilateral, large, simple renal cysts. METHODS: Fifty patients with unilateral, simple renal cysts measuring ≥ 4 cm (cyst group) and 50 kidney donors (control group) were enrolled. Dimercaptosuccinic acid (DMSA) renal scans were performed to calculate split renal function. The differences between split renal function were calculated and compared. Clinical factors affecting decreased renal function in the cyst group were assessed. RESULTS: The mean age of the patients in the cyst group was higher than the control group (59.1 vs 39.2 years; P = 0.001). Patients with renal cysts tended to be diagnosed with hypertension (P = 0.001), However, the two groups did not significantly differ in terms of the other characteristics. The median cyst size was 7.2 cm (range, 4.5-14.2), and 31 of the 50 patients (60.2%) in the cyst group demonstrated decreased renal function in the cystic kidney units (median: 5.8%; range, 0.2-33). Although there were no differences in split renal function (50.1% vs 49.9%; P = 0.629) in the control group, the relative renal function of the cystic kidney units were significantly lower than the contralateral kidney units in the cyst group (48.3% vs 51.7%; P = 0.001). The decrease in relative renal function (>8%) in the cystic kidney units was associated with a higher serum uric acid levels and higher RENAL complexity (P = 0.035 and P = 0.007, respectively). CONCLUSION: A significant proportion of unilateral, large, simple renal cysts are associated with decreased relative renal function on DMSA renal scans.

Effect of percutaneous nephrolithotomy on renal functions in children: assessment by quantitative SPECT of (99m)Tc-DMSA uptake by the kidneys.

OBJECTIVE: To determine the impact of percutaneous nephrolithotomy (PNL) on global and regional renal function in children. METHODS: In total, 40 children (41 renal units) undergoing PNL were included in this prospective study. All patients were evaluated using quantitative single-photon emission computed tomography (QSPECT) with technetium-99 m-dimercaptosuccinic acid ((99m)Tc-DMSA) examinations before and 3 months after surgery. RESULTS: The mean age was 9.5 years (range, 3-16), and the mean stone size was 3.4 cm (range, 2-6.5). Of the cases, 39 (95%) were managed as being stone-free after a single session of PNL. After additional treatment procedures, 40 (97.5%) of the cases were managed as being stone-free. Of the 41 renal units, new focal cortical defects on (99m)Tc-DMSA scans were seen in 4 (9.7%) patients. Total relative uptake in the treated kidneys increased from 42.3% to 44.1%. The mean creatinine level before PNL was 1.18 ± 0.45 (0.8-1.6) mg/dL compared with 1.16 (0.7-1.5) mg/dL by the end of the follow-up period (not statistically significantly different, p > 0.05). CONCLUSIONS: PNL in children is a safe and feasible method for the maximal clearance of stones. QSPECT of (99m)Tc-DMSA confirmed that renal function is preserved or even improved after percutaneous stone removal.

Accuracy of Ultrasound in Identifying Renal Scarring as Compared to DMSA Scan.

OBJECTIVE: To assess the accuracy of renal ultrasound (RUS) in detecting renal scarring (RS). METHODS: All initial DMSA scans performed from 2006 to 2009 for history of urinary tract infection (UTI) or vesicoureteral reflux (VUR) in patients under 14 years old were identified, and clinical history obtained via chart review. Patients who had RUS within 4 months of DMSA scan and no documented UTI during that interval were included. Decreased uptake of tracer associated with loss of contours or cortical thinning defined a positive DMSA study. Increased echogenicity/dysplasia, cortical thinning, atrophic kidney and/or abnormal corticomedullary differentiation defined a positive RUS. The sensitivity and specificity of RUS in identifying RS were calculated using DMSA scan as the gold standard. RESULTS: A total of 144 patients had initial DMSA scans performed for UTI or VUR, with a RUS within 4 months, and no UTI between the 2 studies. Ninety-five of 144 (66%) had RS on DMSA and 49/144 (34%) did not. Patients with or without RS on DMSA were not different in gender (P = .073), age (P = .432), insurance (P = 1.000) or VUR grade (P = .132). Only 39/144 (27.1%) patients had positive RUS. The sensitivity of RUS for RS was 35.8% and the specificity was 89.8%, leading to an accuracy of 54.2% (95%CI; 45.7-62.5%, P = .999). CONCLUSION: RUS demonstrated poor sensitivity for RS visualized on DMSA scan. This suggests that RUS is a poor screening test for RS or indicators of future renal scar. A normal ultrasound does not rule out RS or risk of future renal scar. Specificity of RUS was excellent.

Current pediatric administered activity guidelines for 99m Tc-DMSA SPECT based on patient weight do not provide the same task-based image quality.

PURPOSE: In the current clinical practice, administered activity (AA) for pediatric molecular imaging is often based on the North American expert consensus guidelines or the European Association of Nuclear Medicine dosage card, both of which were developed based on the best clinical practice. These guidelines were not formulated using a rigorous evaluation of diagnostic image quality (IQ) relative to AA. In the guidelines, AA is determined by a weight-based scaling of the adult AA, along with minimum and maximum AA constraints. In this study, we use task-based IQ assessment methods to rigorously evaluate the efficacy of weight-based scaling in equalizing IQ using a population of pediatric patients of different ages and body weights. METHODS: A previously developed projection image database was used. We measured task-based IQ, with respect to the detection of a renal functional defect at six different AA levels (AA relative to the AA obtained from the guidelines). IQ was assessed using an anthropomorphic model observer. Receiver-operating characteristics (ROC) analysis was applied; the area under the ROC curve (AUC) served as a figure-of-merit for task performance. In addition, we investigated patient girth (circumference) as a potential improved predictor of the IQ. RESULTS: The data demonstrate a monotonic and modestly saturating increase in AUC with increasing AA, indicating that defect detectability was limited by quantum noise and the effects of object variability were modest over the range of AA levels studied. The AA for a given value of the AUC increased with increasing age. The AUC vs AA plots for all the patient ages indicate that, for the current guidelines, the newborn and 10- and 15-yr phantoms had similar IQ for the same AA suggested by the North American expert consensus guidelines, but the 5- and 1-yr phantoms had lower IQ. The results also showed that girth has a stronger correlation with the needed AA to provide a constant AUC for 99m Tc-DMSA renal SPECT. CONCLUSIONS: The results suggest that (a) weight-based scaling is not sufficient to equalize task-based IQ for patients of different weights in pediatric 99m Tc-DMSA renal SPECT; and (b) patient girth should be considered instead of weight in developing new administration guidelines for pediatric patients.

Association of vesicoureteral reflux and renal scarring in urinary tract infections. / Asociación entre el reflujo vesicoureteral y la nefroesclerosis en las infecciones urinarias.

INTRODUCTION: The aim was to investigate the relationship between vesicoureteral reflux (VUR) and renal damage in non-febrile, febrile for the first time and recurrent urinary tract infection (UTI) patients. The secondary aim was to determine whether C-reactive protein (CRP) in febrile UTIs could be a predictor of renal scarring. POPULATION AND METHODS: This prospective study included non-febrile, febrile for the first time and recurrent pediatric UTI cases. The routine lab analyses comprised a complete blood count, urea, creatinine, fully automated urinalysis, urine culture and CRP analyses. All the participants were examined using urine ultrasonography subsequent to their UTI diagnosis, voiding cystourethrography (VCUG) after six weeks and Tc-99m dimercaptosuccinic acid (DMSA) static renal scintigraphy after six months. RESULTS: There were included 47 children with non-febrile UTIs, 48 with first febrile UTIs and 61 with recurrent UTIs. A statistically significant difference was found among the groups in terms of VUR and renal scarring (p= 0.001 and p= 0.011, respectively). A statistically significant difference was also found in terms of renal scarring between patients with and without VUR (p= 0.001). Moreover, a statistically significant difference was also present in relation to renal scarring (p <0.05) in patients with five-fold lower or higher CRP values than the accepted cut-off value (5mg/dl). CONCLUSION: The ratio of renal scars detected was found to be parallel to the VUR frequency. The higher the VUR grade, the more renal damage was found. A positive correlation between elevated CRP and renal scarring was determined, indicating the presence of scarring during the diagnosis of pyelonephritis.

Introducción. El objetivo del estudio fue investigar la relación entre reflujo vesicoureteral (RVU) y daño renal en pacientes con infección urinaria (IU) sin fiebre, primera IU febril e IU recurrente. El objetivo secundario, determinar si la proteína C-reactiva (PCR) actuaría como predictor de nefroesclerosis en las IU febriles. Población y métodos. Estudio prospectivo; pacientes pediátricos con IU sin fiebre, primera IU febril e IU recurrente. Los análisis de laboratorio de rutina incluyeron hemograma completo, urea, creatinina, análisis de orina completamente automatizado, urocultivo y PCR. Se realizó ecografía urológica luego del diagnóstico de IU, cistouretrografía miccional tras seis semanas y gammagrafía renal estática con ácido dimercaptosuccínico marcado con 99mTc tras seis meses a todos los participantes. Resultados. Participaron 47 niños con IU sin fiebre, 48 con primera IU febril y 61 con IU recurrente. Hubo una diferencia estadísticamente significativa entre los grupos respecto de RVU y nefroesclerosis (p= 0,001 y p= 0,011, respectivamente). También hubo una diferencia estadísticamente significativa respecto de nefroesclerosis entre los pacientes con y sin RVU (p= 0,001). Además, se estableció una diferencia estadísticamente significativa respecto de nefroesclerosis (p < 0,05) en los pacientes con PCR cinco veces mayor o menor que el valor de corte aceptado (5 mg/dl). Conclusión. La proporción de nefroesclerosis fue paralela a la frecuencia de RVU. Cuanto mayor era el grado de RVU, mayor era el daño renal. Se determinó una correlación positiva entre PCR elevada y nefroesclerosis, lo que señala esclerosis durante el diagnóstico de pielonefritis.

Effect of percutaneous nephrolithotripsy on renal function: assessment with quantitative SPECT of (99m)Tc-DMSA renal scintigraphy.

PURPOSE: To measure the effect of PCNL on global and regional renal function using quantitative single-photon emission CT (SPECT) measurement of Tc-dimercaptosuccinic acid (DMSA) uptake by the kidneys (QDMSA). PATIENTS AND METHODS: A series of 47 male and 41 female patients with a mean age of 47 +/- 16 years were studied by sequential QDMSA examinations before and 1.5 to 24 months after PCNL. Among the 67 patients (76%) in whom PCNL was performed using upper- or lower-pole access, the function of the affected and nonaffected poles of the treated kidney was calculated separately. RESULTS: There was no statistically significant difference in the uptake by the treated kidneys before versus after PCNL (11.9% +/- 5% v 11.6% +/- 5%; t = 0.9; P = 0.368). The total functional volume of the treated kidney was slightly decreased, from 235 cc +/- 62 cc to 224 cc +/- 59 cc (t = 2.7; P = 0.011). The percent of the injected isotope dose per cubic centimeter of tissue of the treated kidney was not affected (0.051 +/- 0.02 v 0.053 +/- 0.02; t = 0.86; P = 0.296). Regional assessment revealed a statistically significant decrease in the functional volume at the PCNL port of entry (91 cc +/- 30 cc v 82 cc +/- 27 cc; t = 2.64; P = 0.013). Regarding the percent of the injected dose per cubic centimeter of renal tissue, no statistically significant difference was found between the area of the kidney that underwent PCNL and the untreated area of the same kidney (0.049 +/- 0.02 v 0.05 +/- 0.02; t = 0.693; P = 0.494). The function of the contralateral kidneys remained unchanged (13.4% +/- 5.2% v 13.6% +/- 4.8%; t = 0.68; P = 0.5). CONCLUSIONS: Despite the statistically significant decrease in the functional volume of the surgically treated region, neither total percent uptake nor percent of injected dose were reduced significantly. Further studies with long-term follow-up of treated kidneys are required.

Effectiveness of diuretic injection on the measurement of differential renal function using Tc-99m DMSA in patients with a dilated renal pelvis.

AIM: The aim of this study was to evaluate the effectiveness of diuretic injection for the measurement of differential renal function (DRF) with technetium-99m dimercaptosuccinic acid (Tc-99m DMSA) scintigraphy in patients with a dilated pelvis. MATERIALS AND METHODS: A total of 46 patients who were referred for both technetium-99m-L,L-ethylenedicysteine (Tc-99m L,L-EC) and Tc-99m DMSA imaging and found to have a dilated collecting system on Tc-99m EC scintigraphy were studied. Four to 5 hours after intravenous injection of Tc-99m DMSA, imaging was performed in the supine position, and posterior, anterior, left and right lateral, and left and right posterior oblique views were taken. After this study, furosemide was administered intravenously and 30 minutes later, additional images in the anterior and posterior views were obtained. RESULTS: The kidneys were evaluated into 2 groups. Group 1 comprised 12 kidneys that had an obstructive curve pattern on Tc-99m EC scans. Group 2 comprised 34 kidneys that had a nonobstructive dilated renogram curve pattern. DRF of the kidneys in each patient were calculated, and the values obtained from the standard and diuretic DMSA scans were compared with each other for all patients and each group. Considering all the patients, the values of mean DRF on both standard and diuretic DMSA images were 55.4%+/-21.2% and 55.4%+/-21.5%, respectively. There were no significant differences between DRF values of each kidney obtained by the 2 methods. When we compared the DRF values in groups 1 and 2, there were again no significant differences. In group 1, the values of mean DRF on standard and diuretic images were 51.7%+/-13.7% and 51.6%+/-13.9%, respectively, and in group 2, the values of mean DRF were 56.7%+/-23.4% and 56.7%+/-23.6%, respectively. CONCLUSION: In view of our study, diuretic administration seems to be an unnecessary intervention because it has no effect on the accuracy of DRF measurements using DMSA scintigraphy in patients with a dilated collecting system whether it is obstructed or not.

Consensus on renal cortical scintigraphy in children with urinary tract infection. Scientific Committee of Radionuclides in Nephrourology.

A questionnaire related to cortical scintigraphy in children with urinary tract infection was submitted to 30 experts. A wide consensus was reached on several issues related to planar images: 99mTc dimercapto succinic acid (DMSA) appears as the most appropriate tracer for renal imaging; dynamic tracers are considered to be inferior, in particular 99mTc diethylenetriaminepentaacetate, which is not recommended. The general opinion is that DMSA scintigraphy is not feasible with a minimal dose below 15 MBq, whereas the maximum dose should not be higher than 110 MBq. The dose schedule generally is based on body surface area, and sedation is only exceptionally given to children. Images are obtained 2 to 3 hours after injection, preferably with high resolution collimators; pinhole images are used by only half of the experts. Posterior and posterior oblique views are used by most of the experts, and the posterior view is acquired in supine positions. At least 200.000 kcounts or 5 minute acquisition is required for nonzoomed images. As a quality control, experts check the presence of blurred or double outlines on the DMSA images. Color images are not used and experts report on film or directly on the computer screen. As far as normal DMSA images are concerned, most experts agree on several normal variants. Hydronephrosis is not a contraindication for DMSA scintigraphy but constitutes a pitfall. Differential renal function generally is measured, but no consensus is reached whether or not background should be subtracted. Most of the experts consider 45% as the lowest normal value. A consensus is reached on some scintigraphic aspects that are likely to improve and on some others that probably represent persistent sequelae. There is a wide consensus for the systematic use of DMSA scintigraphy for detection of renal sequelae, whereas only 58% of the experts are systematically performing this examination during the acute phase of infection.

Evaluation of pentavalent Tc-99m DMSA scintigraphy in small cell and nonsmall cell lung cancers.

AIM: The purpose of this study was to evaluate the clinical usefulness of Tc-99m (V) DMSA in patients suspected of lung cancer and determine whether this agent may have value in differentiation between small cell (SCLC) and non-small cell (NSCLC) lung carcinoma. METHODS: Thirty-six patients with clinical and radiological suspicion of primary lung carcinoma were injected 450-600 MBq of Tc-99m (V) DMSA intravenously. Whole body and planar anterior, posterior thorax images were obtained 4-5 h after injection of the radioactive complex. RESULTS: Histopathological results confirmed 23 NSCLC, 10 SCLC and 1 metastatic lung carcinoma and 2 lung abscess. Nineteen of the 23 (82%) NSCLC and all of the 10 (100%) SCLC cases showed Tc-99m (V) DMSA uptake. Single metastatic lung cancer also accumulated radiotracer. Lung abscess did not show uptake. Lesion/Nonlesion (L/N) ratio of SCLC (1.59 +/- 0.32) and NSCLC (1.43 +/- 0.19) tumour types did not show statistical difference (p > 0.05). Tc-99m (V) DMSA whole body imaging also showed bone metastases. CONCLUSION: Tc-99m (V) DMSA is a noninvasive and cheap imaging method to detect malignant lung cancers and their bone metastases but, differentiation of SCLC and NSCLC is not possible.

Renal uptake rate measurement of 99m Tc-dimercaptosuccinic acid using spectral analysis.

We developed a new method for measuring the rate of renal uptake of 99mTc-dimercaptosuccinic acid (DMSA) using spectral analysis. The renal uptake rate (per minute) of DMSA (K) was calculated by averaging the tissue impulse response function values obtained by spectral analysis between 10 min and 15 min. The K values obtained by spectral analysis correlated well with the renal uptake rates (%) measured 2h after DMSA administration (r=0.921 with background correction; r=0.924 without background correction). There was a good agreement between the K values obtained by spectral analysis using the kidney time-activity curves with (x) and without (y) background correction (r=0.993, y=1.089x+0.004), suggesting that our method requires no background correction. There was excellent correlation between the K values obtained by spectral analysis using the kidney time-activity curves with (y) and without (x) kidney depth correction (r=0.992, y=1.721x+0.000 with background correction; r=0.990, y=1.720x+0.000 without background correction), suggesting that our method requires no kidney depth correction. These results indicate that spectral analysis is appropriate and useful for the quantification of renal uptake rate of DMSA. We believe that this method will facilitate even more widespread utilization of the quantitative assessment of DMSA uptake by planar scintigraphy, since it needs only 10-15 min for imaging, and background and kidney depth correction and blood sampling are not required.

99mTc-DMSA absolute uptake: normal pediatric values at 2-4 hours.

OBJECTIVE: This study aims to determine if normal absolute uptake values of dimercaptosuccinic acid (DMSA) can be predicted accurately over the optimal time for imaging. METHODS: Eighty-eight normal kidneys were analyzed from 44 children with a median age of 4 y. The mean time between injection and scan was 171.7 min. The absolute uptake of DMSA in milligrams was calculated for each kidney. RESULTS: A strong positive linear relationship was found between the absolute uptake of DMSA and the amount of DMSA injected in milligrams (corr = 0.940 [P< 0.0005]), and the age of the child (corr = 0.770 (P<0.0005)). Multiple linear regression showed that these 2 factors accounted for 92.2% of the change in absolute DMSA uptake. CONCLUSION: The absolute uptake of DMSA can be accurately predicted using a linear regression equation incorporating the amount of DMSA injected in milligrams and the patient's age. Time between injection and scan appears to play little role in the absolute uptake of DMSA over 2-4 h.

Role of procalcitonin in predicting dilating vesicoureteral reflux in young children hospitalized with a first febrile urinary tract infection.

OBJECTIVE: The aim of this article was to assess the usefulness of procalcitonin (PCT) as a marker for predicting dilating (grades III-V) vesicoureteral reflux (VUR) in young children with a first febrile urinary tract infection. METHODS: Children ≤2 years of age with a first febrile urinary tract infection were prospectively evaluated. Serum samples were tested for PCT at the time of admission to a tertiary hospital. All children underwent renal ultrasonography (US), Tc-dimercaptosuccinic acid renal scan, and voiding cystourethrography. The diagnostic characteristics of PCT test for acute pyelonephritis and dilating VUR were calculated. RESULTS: Of 272 children analyzed (168 boys and 104 girls; median age, 5 months), 169 (62.1%) had acute pyelonephritis. There was VUR demonstrated in 97 (35.7%), including 70 (25.7%) with dilating VUR. The median PCT value was significantly higher in children with VUR than in those without (P < 0.001). Using a PCT cutoff value of ≥1.0 ng/mL, the sensitivity and negative predictive value for predicting dilating VUR were 94.3% and 95.4%, respectively, for PCT, and 97.1% and 97.8%, respectively, for the combined PCT and US studies, whereas the positive and negative likelihood ratios were 2.03 and 0.107, respectively, for PCT, and 1.72 and 0.067, respectively, for the combined studies. By multivariate analysis, high PCT values and abnormalities on US were independent predictors of dilating VUR. CONCLUSIONS: PCT is useful for diagnosing acute pyelonephritis and predicting dilating VUR in young children with a first febrile urinary tract infection. A voiding cystourethrography is indicated only in children with high PCT values (≥1.0 ng/mL) and/or abnormalities found on a US.

Asociación entre el reflujo vesicoureteral y la nefroesclerosis en las infecciones urinarias / Association of vesicoureteral reflux and renal scarring in urinary tract infections

Introducción. El objetivo del estudio fue investigar la relación entre reflujo vesicoureteral (RVU) y daño renal en pacientes con infección urinaria (IU) sin fiebre, primera IU febril e IU recurrente. El objetivo secundario, determinar si la proteína C-reactiva (PCR) actuaría como predictor de nefroesclerosis en las IU febriles. Población y métodos. Estudio prospectivo; pacientes pediátricos con IU sin fiebre, primera IU febril e IU recurrente. Los análisis de laboratorio de rutina incluyeron hemograma completo, urea, creatinina, análisis de orina completamente automatizado, urocultivo y PCR. Se realizó ecografía urológica luego del diagnóstico de IU, cistouretrografía miccional tras seis semanas y gammagrafía renal estática con ácido dimercaptosuccínico marcado con 99mTc tras seis meses a todos los participantes. Resultados. Participaron 47 niños con IU sin fiebre, 48 con primera IU febril y 61 con IU recurrente. Hubo una diferencia estadísticamente significativa entre los grupos respecto de RVU y nefroesclerosis (p= 0,001 y p= 0,011, respectivamente). También hubo una diferencia estadísticamente significativa respecto de nefroesclerosis entre los pacientes con y sin RVU (p= 0,001). Además, se estableció una diferencia estadísticamente significativa respecto de nefroesclerosis (p < 0,05) en los pacientes con PCR cinco veces mayor o menor que el valor de corte aceptado (5 mg/dl). Conclusión. La proporción de nefroesclerosis fue paralela a la frecuencia de RVU. Cuanto mayor era el grado de RVU, mayor era el daño renal. Se determinó una correlación positiva entre PCR elevada y nefroesclerosis, lo que señala esclerosis durante el diagnóstico de pielonefritis.

Introduction. The aim was to investigate the relationship between vesicoureteral reflux (VUR) and renal damage in non-febrile, febrile for the first time and recurrent urinary tract infection (UTI) patients. The secondary aim was to determine whether C-reactive protein (CRP) in febrile UTIs could be a predictor of renal scarring. Population and methods. This prospective study included non-febrile, febrile for the first time and recurrent pediatric UTI cases. The routine lab analyses comprised a complete blood count, urea, creatinine, fully automated urinalysis, urine culture and CRP analyses. All the participants were examined using urine ultrasonography subsequent to their UTI diagnosis, voiding cystourethrography (VCUG) after six weeks and Tc-99m dimercaptosuccinic acid (DMSA) static renal scintigraphy after six months. Results. There were included 47 children with non-febrile UTIs, 48 with first febrile UTIs and 61 with recurrent UTIs. A statistically significant difference was found among the groups in terms of VUR and renal scarring (p= 0.001 and p= 0.011, respectively). A statistically significant difference was also found in terms of renal scarring between patients with and without VUR (p= 0.001). Moreover, a statistically significant difference was also present in relation to renal scarring (p <0.05) in patients with five-fold lower or higher CRP values than the accepted cut-off value (5mg/dl). Conclusion. The ratio of renal scars detected was found to be parallel to the VUR frequency. The higher the VUR grade, the more renal damage was found. A positive correlation between elevated CRP and renal scarring was determined, indicating the presence of scarring during the diagnosis of pyelonephritis.