New tubular injury markers in children with a solitary functioning kidney

Background

The present study aimed to assess whether the urinary profiles of the lysosomal exoglycosidases N?acetyl?β?hexosaminidase (HEX) and its isoenzymes A (HEX A) and B (HEX B), α-fucosidase (FUC), β-galactosidase (GAL), α-mannosidase (MAN), and β- glucuronidase (GLU) are useful biomarkers of tubular dysfunction in children with a solitary functioning kidney (SFK).

Methods

We measured the urinary activity of HEX, its isoenzymes HEX A, HEX B, and FUC, GAL, MAN, and GLU in 52 patients with SFK. Patients were subdivided into two groups: congenital SFK (cSFK)—unilateral renal agenesis and acquired SFK (aSFK)—unilateral nephrectomy. The reference group (RG) contained 60 healthy sex- and age-matched children.

Results

Urinary activity of all exoglycosidases in SFK was significantly higher than in RG (p?p?>?0.05). HEX and its isoenzymes HEX A and HEX B correlated negatively with estimated glomerular filtration rate (eGFR), and all estimated parameters correlated positively with albumin/creatinine ratio (p?Conclusion Urinary activity of HEX, its isoenzymes HEX A and HEX B, and FUC, GAL, MAN, and GLU is elevated in children with SFK. Long-term follow-up studies in larger groups of children with SFK may help us to better understand their clinical significance.     

Normal kidney size and its influencing factors - a 64-slice MDCT study of 1.040 asymptomatic patients

Background

Normal ultrasound values for pole-to-pole kidney length (LPP) are well established for children, but very little is known about normal kidney size and its influencing factors in adults. The objectives of this study were thus to establish normal CT values for kidney dimensions from a group of unselected patients, identify potential influencing factors, and to estimate their significance.

Methods

In multiphase thin-slice MDCTs of 2.068 kidneys in 1.040 adults, the kidney length pole to pole (LPP), parenchymal (PW) and cortical width (CW), position and rotation status of the kidneys, number of renal arteries, pyelon width and possible influencing factors that can be visualized, were recorded from a volume data set. For length measurements, axes were adjusted individually in double oblique planes using a 3D-software. Analyses of distribution, T-tests, ANOVA, correlation and multivariate regression analyses were performed.

Results

LPP was 108.5 ± 12.2 mm for the right, and 111.3 ± 12.6 mm for the left kidney (p < 0.0001 each). PW on the right side was 15.4 ± 2.8 mm, slightly less than 15.9 ± 2.7 mm on the left side (p < 0.0001), the CW was the same (6.6 ± 1.9 mm). The most significant independent predictors for LPP, CW, and PW were body size, BMI, age, and gender (p < 0.001 each). In men, the LPP increases up to the fifth decade of life (p < 0.01). It is also influenced by the position of the kidneys, stenoses and number of renal arteries (SRA/NRA), infarctions suffered, parapelvic cysts, and absence of the contralateral kidney; CW is influenced by age, position, parapelvic cysts, NRA and SRA, and the PW is influenced in addition by rotation status (p < 0.05 each). Depending on the most important factors, gender-specific normal values were indicated for these dimensions, the length and width in cross section, width of the renal pelvis, and parenchyma-renal pyelon ratio.

Conclusions

Due to the complex influences on kidney size, assessment should be made individually. The most important influencing factors are BMI, height, gender, age, position of the kidneys, stenoses and number of renal arteries.     

Long-term follow-up of blood pressure and glomerular filtration rate in patients with a solitary functioning kidney: a comparison between Wilms tumor survivors and nephrectomy for other reasons

Background

Children with unilateral Wilms tumor (WT) treated with chemotherapy and/or radiotherapy and nephrectomy have excellent survival rates. A solitary functioning kidney (SFK) is associated with progressive renal injury. This study aims to investigate the additional effect of Wilms tumor treatment on renal function compared with children with an SFK for non-oncological reasons.

Methods

A single-center retrospective cohort study on the renal injury markers of 79 survivors of unilateral WT was performed and compared with a matched group of children with an SFK for non-oncological reasons. Mean age at follow-up was 12.4 (SD 5.9) years.

Results

During follow-up, mean estimated glomerular filtration rate (eGFR) and blood pressure z-scores remained stable at an acceptable level. However, in the group of 31 WT patients with a follow-up of 15 years, 23 % showed signs of renal injury. This proportion was smaller than the 54 % in a group of SFK patients based on non-oncological causes (p?=?0.004).

Conclusions

A significant proportion of WT survivors develop renal injury during follow-up. Our data may be an underestimation of the true frequency of progressive renal injury, due to a lack of information on proteinuria. As with patients with a non-oncological SFK, long-term follow-up is essential to monitor WT survivors.

     

Small renal size in newborns with spina bifida: possible causes

Background

Previous studies reported that children with neural tube defects, but without any history of intrinsic renal diseases, have small kidneys when compared with age-matched standard renal growth. The aim of this study was to investigate the possible causes of small renal size in children with spina bifida by comparing growth hormone deficiency, physical limitations and hyperhomocysteinemia.

Methods

The sample included 187 newborns with spina bifida. Renal sizes in the patients were assessed by using maximum measurement of renal length and the measurements were compared by using the Sutherland monogram. According to the results, the sample was divided into two groups—a group of 120 patients with small kidneys (under the third percentile) and a control group of 67 newborns with normal kidney size. Plasma total homocysteine was investigated in mothers and in their children. Serum insulin-like growth factor-1 (IGF-1) levels were measured.

Results

Serum IGF-1 levels were normal in both groups. Children and mothers with homocysteine levels >10 μmol/l were more than twice as likely to have small kidneys and to give to birth children with small kidneys, respectively, compared with newborns and mothers with homocysteine levels <10 μmol/l. An inverse correlation was also found between the homocysteine levels of mothers and kidney sizes of children (r = ? 0.6109 P ≤ 0.01).

Conclusions

It is highly important for mothers with hyperhomocysteinemia to be educated about benefits of folate supplementation in order to reduce the risk of small renal size and lower renal function in children.     

Ambulatory blood pressure monitoring is recommended in the clinical management of children with a solitary functioning kidney

Background

Children with a solitary functioning kidney are at increased risk of developing chronic kidney disease. Hypertension may be an early indicator of renal dysfunction in these patients. We determined blood pressure (BP) profiles of children with a solitary functioning kidney by using ambulatory BP monitoring (ABPM).

Methods

To assess the occurrence with (pre)hypertension, we compared ABPM to office BP measurement in 47 children with a solitary functioning kidney. None of the subjects used antihypertensive agents or had been hypertensive during previous clinical visits.

Results

Mean age of study subjects was 12.7 (±3.3) years. Hypertension was identified in ten (21 %) subjects with ABPM, whereas only two (4 %) children were hypertensive during office BP measurement (p?p?=?0.051). Although 24-h ABPM SD scores were higher in the congenital type than in the acquired type of solitary functioning kidney (p?≤?0.01), the proportions of subjects with 24-h ABPM hypertension were similar between groups (congenital 25 % versus acquired 16 %; p?=?NS).

Conclusions

Based on ABPM, one in five children with a solitary functioning kidney has hypertension. As the majority of these subjects were not hypertensive during office BP measurements, ABPM should be considered in the clinical management of solitary functioning kidney patients.     

Likelihood of children with end-stage kidney disease in Europe to live with a functioning kidney transplant is mainly explained by nonmedical factors

Background

Registry data can be used to assess associations between medical and health-policy factors and the likelihood of children on renal replacement therapy (RRT) to live with a functioning kidney transplant in Europe.

Methods

A survey questionnaire was distributed among renal registry representatives in 38 European countries, and additional data was obtained from the European Society for Pediatric Nephrology/European Renal Association–European Dialysis and Transplant Association (ESPN/ERA-EDTA) registry.

Results

Thirty-two countries with a pediatric RRT program responded. The median percentage of children by country on RRT with a functioning transplant was 62 % (interquartile range 39–77). One per million population increase in donation rate from deceased donors was associated with a 5 % increase in the percentage of functioning transplants; the existence of an intermediate and high pediatric priority policy doubled and tripled this percentage, respectively, compared with no priority, whereas an increase in living donor pediatric kidney transplant rate of one per million children was associated with a 14 % higher percentage of functioning transplants. The percentage of functioning transplants was also strongly associated with the gross domestic product (GDP).

Conclusion

Considerable variations exist in the percentages of prevalent pediatric RRT populations with functioning renal transplants across Europe. A macroeconomic indicator such as GDP is the most important determinant of these international differences. Efforts should be made for living donation programs and pediatric allocation priority to increase access to kidney transplantation for children.     

Renal artery revascularisation can restore kidney function with absent radiotracer uptake

Background

Children with renovascular hypertension often present with severe hypertension. Some children have severe obstruction of their renal arteries resulting in <10% relative function on [^99mTc]dimercaptosuccinic acid (DMSA) scan. Conventional treatment of these children has been nephrectomy of the poorly functioning kidney to normalise their blood pressure (BP).

Case-Diagnosis/treatment

We describe three children aged 20 months to 9 years with severe renal artery stenosis and severe hypertension who had radionucleotide uptake of 0% in one kidney. In one case, no renal perfusion was demonstrated by duplex ultrasound scan. Significant recovery of relative renal function of 18 to 52% was achieved after revascularisation by percutaneous angioplasty or open surgery of the obstructed renal artery.

Conclusion

These cases illustrate that scintigraphy alone cannot be used to predict salvageable function in children with renovascular disease.     

Race-specific relationship of birth weight and renal function among healthy young children

Background

Low birth weight is associated with diminished renal function. However, despite African Americans being at increased risk of low birth weight and chronic kidney disease, little is known about the association between birth weight and renal function in diverse groups. We examined racial differences in the relationship of birth weight and renal function among healthy young children.

Methods

Birth weight and serum creatinine data were available on 152 children (61.8% African American; 47.4% female) from a birth cohort. Estimated glomerular filtration rate (eGFR) was calculated using the bedside Schwartz equation and gender- and gestational-age-adjusted birth weight Z-scores using the US population as a reference. Race-specific linear regression models were fit to estimate the association between birth weight Z-score and eGFR.

Results

Mean age was 1.5?±?1.3?years at first eGFR measurement. African Americans had lower eGFR than non-African Americans (median eGFR?=?82 vs. 95?ml/min per 1.73?m²; p?=?0.06). Birth weight was significantly and positively associated with eGFR among African American (p?=?0.012) but not non-African American children (p?=?0.33).

Conclusions

We provide, for the first time, evidence suggesting that birth weight is associated with renal function in African American children. Future work is needed to determine if prenatal programming helps explain racial disparities in adult health.     

Birth parameters and parental height predict growth outcome in children with chronic kidney disease

Background

We analyzed the impact of birth parameters and parental height on long-term growth outcome in children with chronic kidney disease (CKD) stage 3–5.

Methods

Linear growth was prospectively investigated in 509 children, with a mean follow-up of 4.1 years. Growth outcome was categorized in (i) poor growth (PG): height standard deviation score (SDS) during follow-up <??2.0 and/or actual or previous growth hormone (GH) treatment, and (ii) good growth (GG): height SDS ≥??2.0 and no need for GH. A multivariate binary logistic regression model was constructed for predictors of PG outcome.

Results

PG was observed in 55 % of patients. The rate of pre-term and small for gestational age birth was significantly higher in children with PG compared to GG (43.2 vs. 25.6 % and 36.8 vs. 18.9 %; p?<?0.001). Children with PG had significantly lower average values for gestational age, birth weight, length, and head circumference, umbilical cord pH, Apgar scores, and parental height than children with GG. Birth length, umbilical cord pH, and parental height were significant independent predictors of PG outcome (sensitivity 72.8 %, specificity 69.3 %).

Conclusions

Birth parameters and parental height are independent predictors of growth outcome in children with CKD.     

The association of adult kidney size with childhood vesicoureteral reflux

Background

We used ultrasound to measure kidney volumes in adults with a history of childhood vesicoureteral reflux (VUR) and assessed whether total renal volume, small kidney size or the thickness of the upper pole correlated with renal function or hypertension.

Methods

The kidneys of 123 adults were studied by ultrasound, calculating their volumes using an ellipsoid formula normalised to body surface area (Vol_N). The thickness of the upper pole parenchyma and the number of small kidneys (<80% of normal volume) were recorded. Blood pressure measurements and laboratory tests were also performed.

Results

Kidneys with a history of VUR were 12% smaller than those without known VUR (p?<?0.05), and those with prior dilating VUR were 16% smaller than those with non-dilating VUR (p?<?0.05). There was a moderate correlation (r?=?0.42, p?<?0.05) between total Vol_N and GFR values in the total patient series. Thirteen percent of the patients had a moderate decrease in kidney function. The occurrence of hypertension and proteinuria was not affected by either kidney size or a thin upper pole.

Conclusions

Total Vol_N in ultrasound in early adulthood could probably predict possible renal deterioration in later life. The occurrence of one small kidney was a common finding and seemed not to affect the prevalence of proteinuria or hypertension.     

Growth in children with chronic kidney disease: a report from the Chronic Kidney Disease in Children Study

Background

Growth failure is common among children with chronic kidney disease (CKD). We examined the relationship of growth parameters with glomerular filtration rate (GFR), CKD diagnosis, sex and laboratory results in children with CKD.

Methods

Baseline data from 799 children (median age 11.0 years, median GFR 49.9 mL/min/1.73 m²) participating in the Chronic Kidney Disease in Children Study were examined. Growth was quantified by age–sex-specific height, weight, body mass index (BMI–age), and height–age–sex-specific BMI (BMI-height-age) standard deviation scores (SDS).

Results

Median height and weight SDS were ?0.55 [interquartile range (IQR) ?1.35 to 0.19] and 0.03 (IQR ?0.82 to 0.97), respectively. Girls with non-glomerular CKD were the shortest (median height SDS ?0.83; IQR ?1.62 to ?0.02). Compared to those with a serum bicarbonate (CO₂) level of ≥22 mEq/L, children with CO₂ of <18 mEq/L had a height SDS that was on average 0.67 lower [95 % confidence interval (CI) ?0.31 to ?1.03]. Only 23 % of children with a height SDS of ≤?1.88 were prescribed growth hormone therapy. Forty-six percent of children with glomerular CKD were overweight or obese (BMI-height-age ≥85th percentile).

Conclusions

Growth outcomes in a contemporary cohort of children with CKD remain suboptimal. Interventions targeting metabolic acidosis and overcoming barriers to recombinant human growth hormone usage may improve growth in this population.     

Long-term follow-up of renal transplantation in children: A 20-year experience at one kidney center in Japan

Background

We reviewed the results of renal transplantation in children who has received transplants between October 1973 and January 1984 at our center.

Methods

Twenty-six children, 4 to 15 years of age, underwent renal transplantation from livingrelated donors and were treated using conventional immunosuppressive drugs.

Results

Patient survival rates were 96% at 5 years and 88% at 10 years. Graft survival rates were 69% at 5 years and 45% at 10 years. Four patients died. The main cause of graft loss was chronic rejection. One patient lost the graft due to recurrence of the original disease. Henoch-Schönlein purpura nephritis. The graft was functioning at the end of follow-up in 7 patients, and their serum creatinine levels were all below 1.6 mg/dL at the last follow-up. Noncompliance with medication was confirmed in 4 patients. There was no uncontrollable hypertension observed in any case. Children younger than 5 years showed catch-up growth, but overal growth in these children with renal transplants without growth hormone therapy was not good.

Conclusion

The long-term prognosis of children who underwent living-related renal transplantation using conventional immunosuppressive drugs was favorable, compared to that of adults.     

Development of lymphatic vasculature and morphological characterization in rat kidney

Background

The mechanisms and morphological characteristics of lymphatic vascular development in embryonic kidneys remain uncertain.

Methods

We examined the distribution and characteristics of lymphatic vessels in developing rat kidneys using immunostaining for podoplanin, prox-1, Ki-67, type IV collagen (basement membrane: BM), and ??-smooth muscle actin (??SMA: pericytes or mural cells). We also examined the expression of VEGF-C.

Results

At embryonic day 17 (E17), podoplanin-positive lymphatic vessels were observed mainly in the kidney hilus. At E20, lymphatic vessels extended further into the developing kidneys along the interlobar vasculature. In 1-day-old pups (P1) to P20, lymphatic vessels appeared around the arcuate arteries and veins of the kidneys, with some reaching the developing cortex via interlobular vessels. In 8-week-old adult rats, lymphatic vessels were extensively distributed around the blood vasculature from the renal hilus to cortex. Only lymphatic capillaries lacking continuous BM and ??SMA-positive cells were present within adult kidneys, with none observed in renal medulla. VEGF-C was upregulated in the developing kidneys and expressed mainly in tubules. Importantly, the developing lymphatic vessels were characterized by endothelial cells immunopositive for podoplanin, prox-1, and Ki-67, with no surrounding BM or ??SMA-positive cells.

Conclusion

During nephrogenesis, lymphatic vessels extend from the renal hilus into the renal cortex along the renal blood vasculature. Podoplanin, prox-1, Ki-67, type IV collagen, and ??SMA immunostaining can detect lymphatic vessels during lymphangiogenesis.     

Histological response to injected gluteraldehyde cross-linked bovine collagen based implant in a rat model

Background-

Neglected renal stones remain a major cause of morbidity in developing countries. They not only result in functional impairment of affected kidney, but also act as an important predisposing factor for development of urothelial neoplasms. It is not uncommon to miss an associated urothelial tumor in a patient of nephrolithiasis preoperatively.

Case presentation-

In last 3 years, we came across two patients with giant staghorn calculus and poorly functioning kidneys who underwent laparoscopic nephrectomy. In view of significant perirenal adhesions & loss of normal tissue planes both these patients were electively converted to open surgery. The pathological examination of specimen revealed an unsuspected urothelial carcinoma in both these patients. The summary of our cases and review of literature is presented.

Conclusion-

It is important to keep a differential diagnosis of associated urothelial malignancy in mind in patient presenting with long standing renal calculi. The exact role of a computerized tomography and cytology in preoperative workup for detection of possible associated malignancy in such condition is yet to be defined. Similarly if laparoscopic dissection appears difficult during nephrectomy for a renal calculus with non-functional kidney, keeping a possibility of associated urothelial malignancy in mind it is advisable to dissect in a plane outside gerotas fascia as for radical nephrectomy.     

Roma ethnicity and clinical outcomes in kidney transplant recipients

Background

Racial and ethnic disparities among North American patients with chronic kidney disease have received significant attention. In contrast, little is known about health-related outcomes of patients with end-stage renal disease among the Roma minority, also known as gypsies, compared to Caucasian individuals. We prospectively assessed the association between Roma ethnicity and long-term clinical outcomes in kidney transplant recipients.

Methods

In a prevalent cohort of renal transplant recipients, followed up over a median of 94?months, we prospectively collected socio-demographic, medical (and transplant related) characteristics and laboratory data at baseline from 60 Roma and 1,003 Caucasian patients (mean age 45 (SD?=?11) and 49 (SD?=?13) years, 33 and 41% women, 18 and 17% with diabetes mellitus, respectively). Survival analyses examined the associations between Roma ethnicity and all-cause mortality and death-censored graft loss or death with functioning renal allograft.

Results:

During the follow-up period, 341 patients (32%) died. Two-hundred eighty (26%) patients died with a functioning graft and 201 patients (19%) returned to dialysis. After multivariable adjustments, Roma ethnicity was associated with 77% higher risk of all-cause mortality (Hazard Ratio (HR): 1.77; 95% confidence interval (CI): 1.02, 3.07), two times higher risk of mortality with functioning graft (2.04 [1.17?C3.55]) and 77% higher risk of graft loss (1.77 [1.01?C3.13]), respectively.

Conclusions

Roma ethnicity is independently associated with increased mortality risk and worse graft outcome in kidney transplant recipients. Further studies should identify the factors contributing to worse outcomes among Roma patients.     

Establishment of a normal reference value for serum β2 microglobulin in Japanese children: reevaluation of its clinical usefulness

Objective

Serum β2 microglobulin (β2MG) is considered to be a marker of renal function, which is independently associated with age. However, only a few studies have reported the reference values for β2MG in children thus far, particularly in young children. In this study, we evaluated the distribution of serum β2MG values in healthy Japanese children and assessed its clinical usefulness.

Method

The normal reference value of serum β2MG was assessed in serum samples from 1131 normal Japanese children (504 boys and 627 girls; age 0–17 years). To test the validity of the reference value, serum samples from children with various kidney diseases were also examined retrospectively.

Results

The mean values for β2MG were significantly negatively correlated with age (r = ?0.47, P < 0.001). No significant difference was observed between the values of boys and girls in any age group. The established β2MG reference range covered 99.7 % of patients with decreased kidney function below 75 % based on their serum creatinine (Cr) value and body length.

Conclusion

The newly established β2MG reference value in children can be used to detect kidney impairment in children. Serum β2MG in combination with serum Cr used as markers for predicting glomerular function can provide an accurate detection of kidney dysfunction in children.     

Long-term graft outcome after renal arterial reconstruction during living related kidney transplantation

Background/objectives

The aim of this retrospective study was to evaluate the repair of vascular variations/pathologies in living donor kidney transplantations in a single centre over a 15-year period.

Methods

Between 01/1997 and 05/2012, 338 living donor renal transplantations were performed in the Department for Endovascular and Vascular Surgery, University of Düsseldorf, Germany. Twenty-four of them showed disorders, like multiple renal arteries (MRA), atherosclerotic stenosis or fibromuscular dysplasia (FMD) needing vascular repair before transplantation.

Results

Mean age of donors was 51?±?11.2, in recipient’s 44?±?13.9 years. In seven transplantations, renal artery (RA) repair was performed because of MRA. Atherosclerotic stenosis of the RA was apparent in 12 cases needing a repair with disobliteration. FMD was the reason in five transplantations for vascular repair. Complications like renal vessel thrombosis, lymphocele, heamorrhage, distal urinary leakage and ureteral obstruction was not significantly associated with RA reconstruction. Comparison of renal function in kidneys with reconstructed RA compared with kidneys without vascular repair showed no significant difference in primary function and serum creatinine up to the first year after transplantation. Mean follow-up was 75.6?±?48.1 months. The 5-year graft survival rate for kidneys with RA repair was 88.5 vs. 93.4 % without reconstruction.

Conclusions

We could show that RA pathologies, suitable repaired, are not a contraindication for transplantation with acceptable 5-year-graft-survival rates.     

Prevalence of genetic renal disease in children

Background

Genetic etiology comprises a significant proportion of renal disease in childhood. Completion of the Human Genome Project and increased genetic testing has assisted with the increased recognition of a genetic basis to many renal disorders. Australia and New Zealand have a relatively stable but diverse population, with eight major pediatric nephrology referral centers, which allow ascertainment of disease frequency.

Methods

To determine prevalence, pediatric nephrologists at the eight centers in Australia and New Zealand were surveyed on their estimated number of patients with renal disease of genetic etiology over a 10-year period. Disease prevalence was calculated using combined national population data.

Results

The overall prevalence of genetic kidney disease in children in Australia and New Zealand is 70.6 children per million age-representative population. Congenital anomalies of the kidney and urinary tract (CAKUT) and steroid-resistant nephrotic syndrome (SRNS) are the most frequent, with a prevalence of 16.3 and 10.7, respectively, per million children.

Conclusion

We find a similar prevalence of genetic renal disorders in Australia and New Zealand to those reported in other countries. This is likely to be due to inclusion of children with all forms of renal disease rather than being limited to those with renal impairment.     

Renal impairment in children with posterior urethral valves

Background

Posterior urethral valves (PUV) are a common cause of end-stage renal failure in childhood. Our aim was to describe a cohort of patients with PUV and to investigate the predictors of renal impairment.

Methods

We performed a retrospective chart review of children with PUV who were followed at King Abdulaziz University hospital between 2002 and 2011.

Results

The cohort comprised 68 boys. There was a significant difference in the duration of follow-up (p?=?0.024), nadir serum creatinine (p?<?0.001), and last known serum creatinine level (p?=?0.001) between the patients with and without renal impairment. The duration of follow-up appeared to be a significant predictor for serum creatinine doubling (p?=?0.003; odds ratio, 1.8). There was no difference in the age of presentation, age at the time of the study, and first or last serum creatinine between children who initially had vesicostomy and children who had ablation.

Conclusions

Ablation of PUV or vesicostomy did not influence kidney function in our study cohort. Children with a normal nadir serum creatinine who presented early had a better outcome.     

Efficacy of magnetic resonance urography in detecting renal scars in children with vesicoureteral reflux

Background

The detection of renal scars is of paramount importance for optimal clinical management of patients with urinary tract infection (UTI) and vesicoureteral reflux (VUR). The aim of our study was to compare the efficacy of unenhanced magnetic resonance urography (MRU) and Tc-99^m dimercaptosuccinic acid (Tc-DMSA) scintigraphy to dectect renal scars.

Methods

Unenhanced MRU and Tc-DMSA scintigraphy were performed in 49 children (10 boys, 39 girls; mean age 7.4?±?4.2 years, range 1–15 years) with documented VUR. MR imaging scans were obtained within 7 days after voiding cystourethrogram (VCUG) and Tc-DMSA scintigraphy. The diagnostic performance of MRU in renal scar detection was calculated relative to that of the Tc-DMSA scan.

Results

The renal scar detection rate of Tc-DMSA scintigraphy and unenhanced MRU in kidneys with VUR was 32.4 and 25.9 %, respectively. The sensitivity and specificity of MRU in the detection of renal scars was 80 and 82.6 % in kidneys with VUR, respectively. There was no statistically significant difference in lesion detection between MRU and Tc-DMSA scintigraphy (P?>?0.05). MRU and Tc-DMSA scintigraphy showed good agreement (κ?=?0.60).

Conclusions

Unenhanced MRU is a robust technique for the morphologic assessment of the urinary system and detection of renal scars. The lack of radiation and contrast material makes this technique a much safer alternative to scintigraphy in children with VUR, particularly in those who require follow-up scanning and, consequently, considerable radiation exposure.