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Because loss of functional renal mass is compensated by hyperfiltration of remaining tissue, one could hypothesize that a damaged kidney might not have the same rate of maturation as the contralateral one. To verify this, maturation was evaluated in children with asymmetrical renal function during early life. Twenty-five children were selected having had 2 99mTc-MAG3 renograms combined with 51Cr-EDTA clearance measurement, enabling estimation of glomerular filtration rate (GFR), split renal function (SRF), and single kidney GFR (SKGFR). The first test had to be performed before the age of 18 months and SRF on the affected side had to be ≤40%. Moreover, GFR had to increase between the 2 tests by ≥10 mL-1 min/1.73 m2, reflecting maturation due to age. For 18 children SRF changed by between -5% and +5%. For 4 children an increase of ≥5% was observed whereas for the remaining 3 a decrease of ≥5% occurred. For the first 22 kidneys, mean increase of SKGFR was +6.3 mL-1 min/1.73 m2(SD: 6). For the 3 kidneys with ≥5% SRF decrease, SKGFR remained unchanged in 2 (+0.3 and -3 mL min-1/1.73 m2) and increased in the third patient (+15 mL min-1/1.73 m2). In conclusion, renal maturation is comparable in both the malfunctioning kidney and the contralateral normal functioning side. © IPNA 2005., SCOPUS: ar.j, info:eu-repo/semantics/published

Objective: To quantify the influence of overall renal function on normalized residual activity (NORA) and to evaluate the modifying factors. Methods: A computer simulation model generated renograms by convolution of plasma disappearance curves with artificially created retention functions. From a database, 1099mTc-MAG3 plasma curves were selected, corresponding to renal clearances ranging from 33 to 405 ml·min -1. The retention functions had three properties: (1) until the minimal transit time (MinTT), no output and a linear increase in transit time after MinTT; (2) a ratio of MinTT to mean transit time (MTT) equal to 0.3 or 0.8; and (3) a MTT between 3 and 60 min, increasing in steps of 1 min. The model generated 1160 renograms and for each of them the NORA was calculated at 20, 40 and 60 min. For each value of MTT, the coefficient of variation (CV) of the NORA was calculated at 20, 40 and 60 min. Results: For the same retention function, different clearances resulted in different values of NORA. The degree of variability of NORA depended on several factors, including the time of measurement, the MTT and the MinTT to MTT ratio. For clearances between 100 and 400 ml·min-1, the CV of the NORA ranged from 15% to 30%, whilst for clearances below 100 ml·min-1, the CV of the NORA ranged from 22% to 67%. Little influence of the MinTT to MTT ratio was observed. Conclusion: NORA is influenced by overall renal function. The influence is limited for 99mTc mercaptoacetyltriglycine (99mTc-MAG 3) renal clearances over 100 ml·min-1, whilst for clearances less than 100 ml·min-1, the NORA is influenced much more. © 2004 Lippincott Williams & Wilkins., SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: le.j, info:eu-repo/semantics/published

Introduction: It has been suggested that renal retention function can be estimated by differentiation of the Patlak-Rutland plot. Aim: To evaluate the error resulting from this method. Methods: A total of 5800 renograms were generated by convolving real input functions with artificial retention functions. Ten bi-exponential plasma disappearance curves of 99mTc mercaptoacetyltriglycine (99mTc-MAG3) with varying renal clearances served as input functions and 580 retention functions with mean transit time between 3 and 60 min, and variable ratios of minimal to mean transit time served as original retention functions. The retention function was estimated by differentiation of the Patlak-Rutland plot of each renogram. A variant of this retention function was calculated by setting negative values to zero. Results: Minimal transit time was estimated correctly in all cases but the recovered retention function systematically underestimated the original, and negative values were observed. Mean transit time was underestimated with a difference ranging from -22.05 to -0.06 min. By setting the negative values to zero a less important underestimation was observed which ranged from -13.37 to 0.00 min. Maximal transit time was underestimated systematically with a difference ranging from -22.05 to 0.00 min. All differences were influenced by mean transit time, renal clearance and ratio of minimal to mean transit time. Conclusion: Estimation of the renal retention function by differentiation of the Patlak-Rutland plot results in systematic and sometimes important underestimations. By setting the negative values of the recovered retention function equal to zero, important but still partial improvement can be obtained. © 2004 Lippincott Williams & Wilkins., SCOPUS: ar.j, info:eu-repo/semantics/published

Single blood sample methods are widely used for the estimation of the glomerular filtration rate, but the methods recommended for adults are not the same as those for children. The question arises, therefore, as to which method should be used in an adolescent or young adult The aim of this study was to compare the performance of two methods, a specific paediatric converting equation and an adult algorithm, in a group of adolescent and young adult patients. From a large database of 51Cr-ethylenediaminetetraacetic acid (51Cr-EDTA) renal clearance determinations using the two blood sample method, 598 patients, aged 1 week to 90 years, were selected. The results of the 51Cr-EDTA slope intercept clearance of the two blood sample method were used as reference. Using the paediatric algorithm, no bias was observed until the age of 40 years. Then, an increasing positive bias occurred. The standard deviation of the difference was generally less than 4 ml/min until the age of 25 years and increased gradually to reach 7 ml/min at the age of 80 years. Using the Christensen and Groth adult algorithm, the best results were observed in patients older than 50 years. With the exception of children aged less than 5 years, no systematic bias was observed. The standard deviation, however, increased gradually and reached a value of around 8 ml/min in young children. For individuals aged 15-25 years, the mean of the difference between the paediatric algorithm and the slope intercept method was -1.1 ml/min, with a standard deviation of the difference of 3.3 ml/min. For the adult algorithm, the mean of the difference was 0.3 ml/ min, with a standard deviation of the difference of 7.7 ml/ min. It can be concluded that, for individuals aged 15-25 years, both methods performed correctly. In this series, the paediatric method gave better results than the adult algorithm, and its use is therefore recommended. © 2004 Lippincott Williams & Wilkins., SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: le.j, SCOPUS: le.j, info:eu-repo/semantics/published

Renal transit estimation using renography has been employed for decades. A variety of methods have been developed, ranging from simple quantitative to more sophisticated techniques. In this review, the methods are discussed in perspective of their advantages and drawbacks. Finally, the most robust methods for estimation of renal transit are proposed. © 2004 Lippincott Williams & Wilkins., SCOPUS: re.j, info:eu-repo/semantics/published

SCOPUS: le.j, info:eu-repo/semantics/published

To analyze the current management recommendations among French-speaking physicians treating infants with antenatal renal pelvis dilatation, we surveyed 83 pediatric nephrologists and 68 pediatric urologists by questionnaire. A total of 45 (54%) pediatric nephrologists and 38 (56%) pediatric urologists responded. The threshold for the diagnosis of abnormal fetal renal pelvis dilatation was significantly higher among pediatric urologists than nephrologists. All responders perform renal ultrasound examinations after birth. Postnatal renal pelvis dilatation was considered abnormal if the anteroposterior diameter was ≥11±1.9 mm by the pediatric urologists and ≥9±2.9 mm by the pediatric nephrologists (P=0.003). Pediatric urologists were more likely than nephrologists to recommend routine voiding cystourethrography [41% versus 20% (P=0.04)]. Mercaptoacetyl-triglycine renography was the most routinely used tool to achieve functional evaluation during follow-up among the responders. Pediatric urologists were more likely to recommend surgical treatment in dilated kidneys with initial function <40%. In conclusion, pediatric urologists had significantly higher thresholds for the detection of prenatal and neonatal renal pelvis dilatation. They also more frequently recommended routine voiding cystourethrography and surgical therapy of dilated kidneys with low function than pediatric nephrologists. The variability in attitudes is most probably due to the absence of clear guidelines based on prospective and controlled trials. © IPNA 2004., SCOPUS: ar.j, info:eu-repo/semantics/published

Purpose: The purpose of this study was to evaluate whether some parameters of the basic renogram allow one to omit the administration of furosemide in cases of hydronephrosis. Materials and Methods: One hundred thirty-seven children (274 kidneys) referred for uni- or bilateral hydronephrosis were evaluated retrospectively. In all children additional furosemide challenges followed by postmicturition views were acquired because of unsatisfactory renal emptying. The patients were categorized into 2 groups according to the residual renal activity on the postmicturition view: those with good emptying (R-) of both kidneys, for which the administration of furosemide was considered of no influence, and those with partial or no emptying of at least 1 kidney (R+). The renogram parameters chosen for predicting R+ and R- were time to maximum (T max), output efficiency at 20 minutes (OE20), and normalized residual activity at 20 minutes (NORA20). For each parameter, the number of children was then calculated, for whom the administration of furosemide could have been omitted. Results: A total of 112 children were categorized as R- and 25 as R+. The cutoff values for 100% negative predictive value of Tmax, OE20, and NORA 20 were 4.5 minutes, 66%, and 1.45 respectively. Application of these cutoff values for the parameters yields, in retrospect, 6 (4%), 29 (21%), and 22 (16%) children respectively for whom administration of furosemide could have been omitted. Conclusion: On the basis of OE20 and NORA 20, the administration of furosemide could have been omitted in a substantial number of patients, despite unsatisfactory renal emptying on the basic renogram., SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: le.j, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published