Acid Renal Scan Research Articles

Deep learning-based measurement of split glomerular filtration rate with 99mTc-diethylenetriamine pentaacetic acid renal scan

PurposeTo develop a deep learning (DL) model for generating automated regions of interest (ROIs) on 99mTc-diethylenetriamine pentaacetic acid (DTPA) renal scans for glomerular filtration rate (GFR) measurement.MethodsManually-drawn ROIs retrieved from a Picture Archiving and Communications System were used as ground-truth (GT) labels. A two-dimensional U-Net convolutional neural network architecture with multichannel input was trained to generate DL ROIs. The agreement between GFR values from GT and DL ROIs was evaluated using Lin’s concordance correlation coefficient (CCC) and slope coefficients for linear regression analyses. Bias and 95% limits of agreement (LOA) were assessed using Bland-Altman plots.ResultsA total of 24,364 scans (12,822 patients) were included. Excellent concordance between GT and DL GFR was found for left (CCC 0.982, 95% confidence interval [CI] 0.981–0.982; slope 1.004, 95% CI 1.003–1.004), right (CCC 0.969, 95% CI 0.968–0.969; slope 0.954, 95% CI 0.953–0.955) and both kidneys (CCC 0.978, 95% CI 0.978–0.979; slope 0.979, 95% CI 0.978–0.979). Bland-Altman analysis revealed minimal bias between GT and DL GFR, with mean differences of − 0.2 (95% LOA − 4.4–4.0), 1.4 (95% LOA − 3.5–6.3) and 1.2 (95% LOA − 6.5–8.8) mL/min/1.73 m² for left, right and both kidneys, respectively. Notably, 19,960 scans (81.9%) showed an absolute difference in GFR of less than 5 mL/min/1.73 m².ConclusionOur DL model exhibited excellent performance in the generation of ROIs on 99mTc-DTPA renal scans. This automated approach could potentially reduce manual effort and enhance the precision of GFR measurement in clinical practice.

Investigation of the Effects of N-acetylcysteine and Selenium on Vesicoureteral Reflux Nephropathy: An Experimental Study

IntroductionThis study aimed to investigate the effects of N-acetylcysteine (NAC) and selenium (Se) on vesicoureteral reflux (VUR) nephropathy. MethodsA total of 44 rabbits in 7 groups, namely group 1 (Control), group 2 (VUR + sterile urine), group 3 (VUR + sterile urine + NAC), group 4 (VUR + sterile urine + Se), group 5 (VUR + infected urine), group 6 (VUR + infected urine + NAC) and group 7 (VUR + infected urine + Se), were used. 99mTc Dimercaptosuccinic acid renal scan (DMSA), cystogram and urine culture were performed both at the beginning and end of the study. Left VUR was created surgically, and E. coli was inoculated in infected urine groups. NAC and Se were administered daily for 21 days. Malondialdehyde (MDA) measurement, inflammatory response scores (IRSs), and cicatrization response scores (CRSs) in renal tissues were evaluated. ResultsVUR did not reduce left renal uptake values in neither group 2 nor group 5. MDA levels of the left kidney were significantly higher in group 5 compared to group 1 (p = 0.001). There was no significant difference in MDA levels between group 5 and group 6, and between group 5 and group 7. Left kidney IRSs were found to be higher in all other groups except group 2 compared to the control group (p < 0.001). Left kidney CRSs were significantly higher in group 5 compared to group 2 (p = 0.026), group 6 (p < 0.001) and group 7 (p = 0.006). ConclusionA decrease in renal functions was not observed in VUR, even if there was infection. When CRSs were evaluated, NAC and Se had protective effects in terms of scar formation in VUR nephropathy. Type of StudyExperimental animal study. Levels of EvidenceN/A.

Multicystic renal dysplasia, a histomorphological spectrum: Seven years experience from a tertiary care hospital.

Multicystic dysplastic kidney (MCDK) is defined as the presence of multiple noncommunicating cysts of various sizes, detected sonographically, without evidence of functioning renal parenchyma on dimercaptosuccinic acid renal scan. It has an incidence of 1:4000 live births. They are more commonly diagnosed in boys, usually on the left side, but may also be bilateral. There is the presence of primitive ducts surrounded by fibromuscular connective tissue. These are because of the disturbed connection of the ureteric bud with renal blastema and abnormal division at the stage of metanephros, resulting in an abnormal metanephros differentiation. Thirty cases of MCDK were included to study their histomorphology along with their clinical features. Cases were retrieved from the last seven years (2015-2021) from the Department of Pathology, Maulana Azad Medical College. Age ranged from 10 days to 18 years. The cases were between 1 years and 5 years of age. Six out of 30 cases (20%) were infants with three of them being neonates. Twenty-one cases were males. All the cases had unilateral kidney involvement with the left kidney being involved in 20 out of 30 cases. Twenty-eight cases underwent nephrectomy in view of small contracted nonfunctional kidneys with one of them being horseshoe shaped. Five cases had associated hydronephrosis (two ipsilateral and three bilateral). One case had Hirshprung's disease, four had anorectal malformation, two had posterior urethral valves with vesicourethral reflux, one had duplex moiety, and one had undescended testes. On histopathological examination, all of them showed the presence of immature disorganized tubules surrounded by a collarette of immature mesenchymal stroma. One of the cases showed osteoid formation and four had areas of immature cartilage. Normal kidney parenchyma was seen at the periphery in four cases. This series has been presented to highlight the various histomorphological features of MCDK. MCDK can be managed conservatively in most of cases due to autoinvolution and, hence, needs to be differentiated from other close differentials like polycystic kidney disease, cystic nephroma, and cystic partially differentiated nephroblastoma in order to avoid unnecessary surgical intervention.

Posterior urethral valve in thai boys

BackgroundPosterior urethral valve (PUV) is the most common congenital bladder outlet obstruction in boys, causing renal damage beginning in utero. There are scarce data from Thailand regarding the long-term outcomes of PUV in boys, thus the aim of this study was to examine the presentation, clinical course, complications, outcomes and renal survival in PUV boys.MethodsWe reviewed the medical records of PUV boys treated at the Pediatric Nephrology Clinic, Prince of Songkla University, Thailand, over a 30-year-period.ResultsSeventy-seven PUV boys were identified, with a median age at diagnosis of 4.8 months. The most common presentations were urinary tract infection (UTI), poor urine stream and urinary dribbling in 26 (33.8%), 19 (24.7%) and 11 (14.3%) boys, respectively. Renal ultrasound results in 70 boys showed 8 (11.4%) unilateral and 56 (80%) bilateral hydronephroses. Of 72 voiding cystourethrograms, 18 (25.0%) showed unilateral and 22 (30.6%) bilateral vesicoureteral refluxes. 99mTc dimercaptosuccinic acid renal scans in 30 boys showed 12 (40%) unilateral and 8 (26.7%) bilateral renal damage. Fifty-nine (76.6%) boys had 149 UTIs; 42 (54.4%) had recurrent UTI. Forty-eight boys had valve ablation at the median age of 30.3 months. 22 boys (28.6%) developed chronic kidney disease (CKD) at a median age of 15.0 years.ConclusionOf 77 PUV Thai boys, UTI was the most common presentation. Recurrence of UTI and CKD was the most common consequence. Lifelong follow-up for renal and bladder functions is essential for all PUV patients.

Clinical and etiological profile of Complicated Urinary Tract Infection in Children: A health facility-based cross-sectional study

Background: Urinary tract infection (UTI) is known to be the most frequent bacterial infection in the paediatric population. Objective: To determine the clinical profile and etiology of complicated urinary tract infection (UTI) in children. Methods: This cross-sectional study was done at the Department of Nephrology and Neonatology, National Institute of Child Health, Karachi from 1st January 2022 to 30th June 2022. In 241 children of either gender, (male and female) aged up to 15 years having structural or functional anomalies of the kidney and urinary tract or recurrent infection due to underlying kidney or urinary tract abnormalities were enrolled. Demographic and clinical characteristics along with laboratory parameters and etiological agents of complicated UTI were noted. Ultrasonography examination and dimercaptosuccinic acid (DMSA) renal scan (where indicated) were performed. Results: Of 241 children, 179 (74.3%) were male. The mean age was 3.08±3.63 years. Capillary refill time was prolonged in 78 (32.4%) children. Fever/chills, nausea/vomiting, urinary urgency, and dehydration were the most frequently noted clinical presentations reported in 232 (96.2%), 109 (45.2%), 91 (37.8%), and 89 (36.9%) children respectively. Ultrasonography findings were evident of bilateral moderative hydronephrosis in 60 (24.9%) children. E. coli followed by Pseudomonas and Klebsiella species were the most commonly found etiological agents noted in 98 (40.7%), 50 (20.7%), and 40 (16.6%) children respectively. Conclusion: The majority of the children with complicated UTIs were male. Fever/chills, nausea/vomiting, urinary urgency, and dehydration were the most frequently noted clinical presentations. The most commonly observed ultrasonography findings were bilateral moderative hydronephrosis

Clinical Profiles and Outcomes of Renal Scarring in Children Underwent Dimercaptosuccinic Acid (DMSA) Renal Scan in A Tertiary Hospital

Introduction: Renal scarring, which can be detected by DMSA renal scan, has been demonstrated to cause hypertension, proteinuria and chronic kidney disease (CKD). We reviewed the proportion of renal scarring, risk factors and outcomes among children who were referred for DMSA scan in a tertiary teaching hospital. Methods: All records of children less than 18 years old who underwent DMSA scan over a ten-year period, were reviewed. Among children whose renal cortical defects were confirmed by DMSA scan, data of their risk factors and its outcome were collected manually. Results: Out of 92 children referred for DMSA scan, half were detected to have renal scarring. Vesico-ureteric reflux (VUR) was significantly associated with the development of renal scarring. CKD (27.1%) and hypertension (12.5%) were the commonest complications. The median duration between diagnosis of the complications and detection of renal scarring was 1 year. Conclusion: A high proportion of children undergoing DMSA scans had renal scarring and early development of serious complications was common.

Predictors of renal scars in infants with recurrent febrile urinary tract infection: a retrospective, single-center study

Purpose: To determine predictive factors for detecting renal parenchymal damages (RPDs) in infants with recurrent febrile urinary tract infection (fUTI).Methods: From January 2015 to December 2021, 102 infants with recurrent fUTI and who underwent 99mTc-dimercaptosuccinic acid (DMSA) renal scan in our hospital were included in this study. Controls included infants with normal DMSA results performed 3 months apart from the 2nd episode of fUTI. DMSA-positive group included infants with positive DMSA results performed 3 months apart from the 2nd episode of fUTI or at the 3rd episode of fUTI. The recurrence rate, causative bacteria, renal size discrepancy of both kidneys, and laboratory findings including C-reactive protein (CRP) and spot urine sodium-to-potassium ratio (uNa/K) were compared between both groups.Results: Only 3.8% of 79 infants with a 2nd episode of fUTI showed positive DMSA results. fUTI recurred more frequently within 12 months of follow-up in the DMSA-positive group than in the control group (69% vs. 13%, P=0.00). CRP values were significantly higher in the DMSA-positive group than in the control group (7.3 mg/dL vs. 3.7 mg/dL, P=0.00). Spot uNa/K were significantly lower in the DMSA-positive group than in the control group (0.6 vs. 1.1, P=0.00). Conclusions: Congenital renal scar and RPDs on the DMSA scan were more frequently found in infants with recurrent fUTI than those in the control group. High CRP values and low spot uNa/K in acute infections were helpful in predicting the presence of RPD in infants with recurrent fUTI.

Correlation of Renal Scarring to Urinary Tract Infections and Vesicoureteral Reflux in Children.

Objective To study the association of the grade of vesicoureteral reflux (VUR) and urinary tract infections (UTI) with renal scarring at the first clinical presentation of patients who underwent antireflux surgery. Materials and methods. Between 2015 and 2020, 150 patients (194 units) who underwent antireflux surgery had dimercaptosuccinic acid (DMSA) renal scans preoperatively. Patients were classified into the nonscar and scar groups according to DMSA scan results. Moreover, cases were classified into afebrile UTI, febrile UTI, and antenatal hydronephrosis (ANH) according to the mode of presentation. We correlated the mode of presentation and the grade of VUR to the presence/absence of renal scars in both groups. Results The mean follow-up was 45 months preoperatively. The mode of presentation was afebrile, febrile UTIs, and antenatal hydronephrosis in (50, 14), (20, 46), and (10, 10) patients in the nonscar and scar groups, respectively. Of the 20 patients who presented ANH, 10 (50%) had scars. Clinical presentation was correlated to the presence of renal scarring and its degree. The scar group had significantly higher grades of VUR than the nonscar group (grades I–II (50 units versus 10 units), grade III (28 units versus 40 units), and grade IV–V (22 units versus 44 units) for the nonscar versus scar groups, respectively (pvalue <0.001). Conclusion Renal scarring is associated with higher grades of reflux and urinary tract infections. We advocate further research investigating infants who had UTIs with or without fever for early detection of reflux.

Prediction of Recurrent Urinary Tract Infection in Paediatric Patients by Deep Learning Analysis of 99mTc-DMSA Renal Scan.

Purpose: Tc-99m dimercaptosuccinic acid (99mTc-DMSA) renal scan is an important tool for the assessment of childhood urinary tract infection (UTI), vesicoureteral reflux (VUR), and renal scarring. We evaluated whether a deep learning (DL) analysis of 99mTc-DMSA renal scans could predict the recurrence of UTI better than conventional clinical factors. Methods: the subjects were 180 paediatric patients diagnosed with UTI, who underwent immediate post-therapeutic 99mTc-DMSA renal scans. The primary outcome was the recurrence of UTI during the follow-up period. For the DL analysis, a convolutional neural network (CNN) model was used. Age, sex, the presence of VUR, the presence of cortical defects on the 99mTc-DMSA renal scan, split renal function (SRF), and DL prediction results were used as independent factors for predicting recurrent UTI. The diagnostic accuracy for predicting recurrent UTI was statistically compared between independent factors. Results: The sensitivity, specificity and accuracy for predicting recurrent UTI were 44.4%, 88.9%, and 82.2% by the presence of VUR; 44.4%, 76.5%, and 71.7% by the presence of cortical defect; 74.1%, 80.4%, and 79.4% by SRF (optimal cut-off = 45.93%); and 70.4%, 94.8%, and 91.1% by the DL prediction results. There were no significant differences in sensitivity between all independent factors (p > 0.05, for all). The specificity and accuracy of the DL prediction results were significantly higher than those of the other factors. Conclusion: DL analysis of 99mTc-DMSA renal scans may be useful for predicting recurrent UTI in paediatric patients. It is an efficient supportive tool to predict poor prognosis without visually demonstrable cortical defects in 99mTc-DMSA renal scans.

Protective Effects of Omega-3 Fatty Acids Supplementation Against Renal Parenchymal Scarring in Children with Acute Pyelonephritis: Results of a Pilot Clinical Trial.

This trial aimed to determine if supplementation with omega-3 fatty acids as an adjunct therapy to antibiotic treatment can have protective effects against renal scar formation after acute pyelonephritis (APN) in pediatric patients. Current evidence points out that besides antibiotic treatment, early administration of antioxidant and anti-inflammatory compounds may be effective in reducing the occurrence of renal damage following APN in children. The main endpoint of the trial was the comparison of the development of renal scarring formation after APN in an omega-3 fatty acids-treated group and in a control-treated group. This prospective randomized, controlled trial study was conducted from March 2016 to May 2018 on 60 children with a diagnosis APN in a tertiary hospital in Iran. After the diagnosis of APN based on the clinical signs and symptoms, urine analysis, urine culture, and dimercaptosuccinic acid renal scan (DMSA scan), the patients were randomly allocated into either the control group (n=30 patients: received standard antibiotic treatment only) or the intervention group (n=30 patients: received standard antibiotic-treatment in combination with oral omega-3 fatty acids based on the children's weight for three consecutive days). A second DMSA scan was performed for the patients at a minimum of six months after treatment. The development of renal scars was evaluated by comparing the baseline DMSA scan lesions with the follow-up DMSA scan lesions. Fifty patients, including 26 and 24 individuals in the control and intervention groups, respectively, completed the entire course of the study. Renal parenchymal involvement based on the baseline DMSA scan was similar in the two groups (p-value =0.85, 0.90, and 0.53 regarding the right, left, and both kidney units together, respectively). Although comparison of the follow-up DMSA scan lesions to the baseline DMSA scan lesions considering the right and left kidneys as separate units between two groups did not reach the significant level, when considering both left and right kidney units together, results showed a statistically significant difference between groups in favor of the intervention group (p-value =0.04). Although preliminary, the results of this study showed that administration of omega-3 fatty acids, a natural supplement with well-known anti-inflammatory and antioxidant properties, as an adjunct therapy to standard antibiotic treatment might significantly reduce the incidence of the occurrence renal scarring following APN in children. Confirmation of these results requires further studies.

Evaluation of the Relationship of the Time of Vesicoureteral Reflux Between Renal Scar Development and Endoscopic Treatment Success in Early Childhood

INTRODUCTION: Vesicoureteral reflux (VUR) is an important cause of urinary tract infection and chronic renal disease. Voiding cystourethrography (VCUG) is the gold standard diagnostic test in the diagnosis of VUR. In recent years, new parameters related to VCUG have been more objectively studied to evaluate the clinical prognosis. It is aimed to evaluate the effect of reflux time in primary VUR in terms of predicting endoscopic treatment success and treatment timing in VUR management. METHOD: In our study, the records and imaging findings of children with primary VUR who underwent VCUG examination between 2012 and 2019, who were treated with endoscopic injections, were retrospectively reviewed. Forty one children (67 renal units) were included in our study. Patients with preoperative VCUG, urinary ultrasonography, dimercaptosuccinic acid (DMSA) renal scan, and post-operative control VCUG were included in this study. RESULTS: Patients with preoperative VUR grade 1-2 were divided into two groups as “low grade” and patients with stage 3-4-5 as “high grade”. In the general patient population, endoscopic success rates in terms of renal unit deficit were found to be 46.3% (31/67). When the subgroup was analyzed, the endoscopic treatment success rate was 72.2% (13/18) in the low-grade group, versus 36.7% (18/49) in the high-grade group (p = 0.010). In the multivariate logistic regression analysis performed to identify independent predictors of scarring, reflux degree and reflux time were found to be independent predictors of scarring. CONCLUSION: In our study, we found that in VCUG evaluated preoperatively, VUR time as well as VUR grade were effective on endoscopic success rate and scar development. Based on these results, it could be thought that VUR time may be effective in selecting the best candidates for surgery and in the management and timing of treatment of VUR patients.

Prediction of renal function improvement in azotemic patients using glomerular filtration rate from 99mTc-DTPA renal scan: An observational study.

This study aimed to evaluate the ratio of glomerular filtration rate (GFR) from 99mTc-diethylenetriamine-pentaacetic acid dynamic renal scan (GFRSCAN) to estimated GFR (eGFR) as a predictor of renal function improvement in patients with azotemia.A retrospective review of medical records was conducted to identify consecutive patients with newly discovered or aggravated azotemia who underwent 99mTc-diethylenetriamine-pentaacetic acid renal scan. Significant renal function improvement was defined as ≥100% and ≥10 mL/min improvement of eGFR at 12 weeks compared to eGFR on the day of renal scan (eGFR0). The GFRSCAN/eGFR0 ratio was evaluated as a predictor of significant renal function improvement using logistic regression and receiver operating characteristic (ROC) curve analyses. Added value of the GFRSCAN/eGFR0 ratio in the prediction of significant renal function improvement were demonstrated by adjusting for best clinical predictor variables.The eligibility criteria were met by 224 patients, among whom 22 patients (9.8%) showed significant renal function improvement. The odds ratios of the GFRSCAN/eGFR0 ratio for predicting significant renal function improvement were 1.76 (95% confidence interval [CI]: 1.26–2.45, P < .001) in the univariable analysis and 1.70 (95% CI: 1.19–2.42, P = .003) after adjusting for clinical variables. The area under the ROC curve of the GFRSCAN/eGFR0 ratio for predicting significant renal function improvement was 0.762 (95% CI: 0.648–0.871). The addition of the GFRSCAN/eGFR0 ratio to the best clinical prediction model raised the area under the ROC curve from 0.726 to 0.794, and this increment was statistically significant (P = .02).The GFRSCAN/eGFR ratio can predict renal function improvement in patients with azotemia. Future prospective studies are necessary to validate its potential clinical utilities.

Contrast-enhanced voiding ultrasonography to detect intrarenal reflux in children: comparison with 99mTc-DMSA renal scans.

PurposeThis study evaluated the diagnostic performance of contrast-enhanced voiding ultrasonography (CeVUS) for detecting intrarenal reflux (IRR) and the correlation between CeVUS-detected IRR sites and photon defect sites in acute 99mTc-dimercaptosuccinic acid (DMSA) renal scans in pediatric patients.MethodsFifty-four kidneys from 27 patients (20 males and seven females; mean age, 5.6±4.1 months) who underwent CeVUS and acute DMSA renal scans for recurrent urinary tract infection (UTIs) or pyelonephritis were included. Pediatric experts compared the results of CeVUS with acute DMSA renal scans.ResultsThirteen renal units (13/54, 24.1%) in 10 patients (nine males and one female; mean age, 6.3±3.7 months; age range, 0 to 13 months) showed vesicoureteral reflux and eight renal units (8/54, 14.8%) demonstrated IRR on CeVUS. Ten renal units in eight patients (six males and two females; mean age, 6.9±1.4 months; age range, 2 to 13 months) showed 19 photon defects on acute DMSA renal scans. Fifty-two renal units (96.3%) showed concordant results, and two renal units (3.7%) showed discordant results between CeVUS and acute DMSA renal scans. IRR accounted for 15/19 (78.9%) photon defects in eight renal units of seven patients using CeVUS. In a per-renal-unit analysis, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CeVUS were 80%, 100%, 100%, 95.7%, and 96.3%, respectively.ConclusionCeVUS showed good performance in detecting IRR, and the IRR sites detected by CeVUS closely correlated with photon defect sites in acute DMSA scans. CeVUS may play an important role in managing patients with recurrent UTIs or pyelonephritis with reduced radiation exposure.

Glomerular Filtration Rate Estimation With Commonly Used Methods Among Healthy Live Kidney Donors of South Punjab, Pakistan.

BackgroundAccurate estimation of the donor’s glomerular filtration rate (GFR) is crucial for not only ensuring the medical appropriateness of the donor but also for the prediction of future allograft performance. The aim of this study was to compare the GFR estimation formulas and 24-hour urine creatinine clearance with diethylene triamine pentaacetic acid (DTPA) renal scan GFR.MethodsThis cross-sectional study was done at the Department of Nephro Urology Dialysis & Renal Transplantation, Bahawal Victoria Hospital, Quaid e Azam Medical College, Bahawalpur, Pakistan from September 2018 to September 2021. A total of 92 potential healthy live-related kidney donors of both genders, aged 18 to 60 years having body mass index below 35 kg/m2 were included. GFR was calculated with modification of diet in renal disease (MDRD), Cockcroft-Gault (CG), chronic kidney disease epidemiology (CKD-EPI) equations as well as by 24-hour urine creatinine clearance. DTPA renal scan was done to record GFR findings. GFR was compared using analysis of variance (ANOVA) among different methods.ResultsOut of a total of 92 individuals, 49 (53.3%) were male and 43 (46.7%) female. Mean age and BMI were noted to be 34.62±10.57 years and 24.40±2.71 kg/m2, respectively. Statistically significant differences existed between various methods of GFR estimation (p<0.001). Mean GFR as per DTPA renal scan findings was noted to be 97.32±9.39 ml/min/1.73 m2. Difference of 31.48±20.81, 27.37±21.1, 23.38±6.38, 15.52±37.52 was noted in estimated GFR (ml/min/1.73 m2) with CG formula, MDRD formula, EPI-CKD formula and 24-hour urine creatinine clearance respectively when compared with DTPA renal scan findings. The highest proportion of patients was seen with normal GFR with DTPA renal scan findings as 83 (90.2%) individuals while 24-hour urine creatinine clearance observed these to be 59 (64.1%), CG EPI-CKD formula 44 (47.8%), MDRD formula 39 (42.4%) and 40 (43.5%) with CG formula.ConclusionNone of the GFR estimation methods resulted in similar findings. With reference to the DTPA renal scan, 24-hour urine creatinine clearance was the closest GFR estimation followed by CKD-EPI and MDRD equations.

Modified Schwartz formula and 99mTc-DTPA plasma clearance methods to calculate glomerular filtration rate in critically ill children.

Studies comparing the modified Schwartz formula with measured GFR (m-GFR) are lacking in critically ill children. This prospective cohort study enrolled children aged 1 month to 12 years, within 24 h of admission. m-GFR measured by technetium-99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA) and calculated by Russell's two-sample slope-intercept method. Serum creatinine was estimated by modified Jaffe method and estimated GFR (e-GFR) calculated by modified Schwartz formula. The primary outcome was to find agreement between the two methods. Bias, precision, and accuracy were calculated. Secondary outcomes were the incidence of AKI (by p-RIFLE criteria) and the difference between the two methods to diagnose AKI. A total of 208 pairs were analyzed. e-GFR showed good agreement with m-GFR with a mean bias of -4.37 ml/min/1.73 m2 and precision (SD of bias) of 33.07, 95% limit of agreement -69.18 to 60.45, and intraclass correlation of 74% (95%CI 66-80%, P < 0.001). e-GFR underestimated m-GFR by 19.8% (95% CI 7.9-31.7%). Accuracy of e-GFR values within 10%, 20%, and 30% of m-GFR were 68.3%, 72.6%, and 78.8%, respectively. Incidence of AKI within 24 h was 60.1% by e-GFR and 54.3% by m-GFR (kappa 0.569, P < 0.001; sensitivity of 85.8%, 95%CI (78-91.7%). The modified Schwartz formula shows good agreement with 99mTc-labeled DTPA double plasma sample clearance method for calculating GFR in critically ill children aged 1 month to 12 years. The underestimation of GFR should be kept in mind while applying the formula at the bedside in PICU. Protocol accessible at Clinical Trial Registry of India (CTRI) www.ctri.nic.in . (Trial Registered Prospectively and Registration No. CTRI/2017/10/010014) ([Registered on: 06/10/2017] Trial Registered Prospectively.) (Title "Measured glomerular filtration rate using Diethylenetriaminepentaacetic acid (DTPA) renal scan versus estimated glomerular filtration rate using modified Schwartz formula in critically ill children: A prospective observational, analytical study."). A higher resolution version of the Graphical abstract is available as Supplementary information.

Transperitoneal laparoscopic ureteropyeloplasty of retrocaval ureter: Single surgeon experience and review of literature.

Retrocaval ureter (RCU) is a rare congenital abnormality, secondary to anomalous development of inferior vena cava (IVC) presenting as ipsilateral obstruction needing surgical intervention. The aim of this article is to present surgical techniques and outcome of transperitoneal laparoscopic ureteropyeloplasty in patients with RCU treated by a single surgeon at a tertiary care center and with review of literature. We conducted a retrospective, institutional review board approved chart review of patients who underwent transperitoneal laparoscopic ureteropyeloplasty for RCU at our unit between January 2010 and December 2020. A total of 10 patients were identified. Preoperative evaluation involved a computed tomography-intravenous urography in addition to the conventional evaluation. All the patients underwent dismembered transperitoneal laparoscopic ureteropyeloplasty over a Double J stent. Data analyzed included the demographic profile, operative time difficulty if any, postoperative, intraoperative complications and functional outcome. All cases were completed laparoscopically and no open conversion was required. Average operating time was 96.6minutes± 8.16. Average blood loss was 71 ± 14.49 mL with an analgesia requirement of 115 ± 33.74 mg. One patient developed postoperative urinary leak and responded to percutaneous nephrostomy drainage. Patients were followed up for 3 to 12 months with a serial ultrasound and a follow-up diethylene-triamine-penta-acetic acid renal scan at 3months to rule out any anastomotic site obstruction. Transperitoneal laparoscopic ureteropyeloplasty for RCU was associated with minimal morbidity and good outcomes.

Intrarenal Reflux Diagnosed by Contrast-enhanced Voiding Urosonography - a Case Report

Objective − Intrarenal reflux (IRR) is the main cause of renal injury in children with vesicoureteral reflux (VUR), and has an important role in the pathogenesis of scarring and reflux nephropaty (RN). Using voiding cystourethrography (VCUG) IRR is usually detected in high grades of VUR. Our case demonstrates the possibility of visualizing IRR in a child with low-grade VUR using contrast-enhanced voiding urosonography (ceVUS). Case Report − We report the case of a four-month-old girl with Klebsiella pneumoniae febrile urinary tract infection (UTI) who was diagnosed by ceVUS with VUR grade II on the right kidney, with IRR strongest in the lower pole. A 99m Tc 2.3-dimercaptosuccinic acid (DMSA) renal scan, which was performed 8 months after the UTI revealed a small scar on the lower pole of the right kidney, where IRR was found by ceVUS. Conclusion − Our case report showed that not only the grade of reflux but also the presence of IRR is important to predict the severity of the clinical picture and the development of possible scarring. It is important to find IRR because it may be connect with renal scars. VUR with IRR should be managed actively to decrease the chances of renal scarring or the development of new scars.

Estimation of Glomerular Filtration Rate and Predicting Diagnostic Accuracy of Cystatin C and Creatinine in Detection of Renal Function among Longstanding Type-2 Diabetics

Introduction: Estimation of Glomerular Filtration Rate (GFR) is dependent on Serum Creatinine (SCr). Though, a sudden decrease in GFR would not result in rapid rise in concentrations of SCr, as they are imprecise but it leads to the over diagnosis of Chronic Kidney Disease (CKD). Aim: To calculate GFR using Cystatin-C (Cys-C) based formulas to contrast its accuracy with SCr based formulas and to predict the diagnostic accuracy of Cys-C in patients with diabetes. Materials and Methods: A total 48 type-2 diabetic patients were diagnosed with CKD and their GFR was assessed using the Cys-C and SCr. GFR was measured and estimated using three equations (Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CDK-EPI), that are based on SCr and three equations (LeBricon, Grubb and Hoek) based on Cys-C among the 48 CKD patients. The filtration rate was measured using labelled diethylenetriaminepentaacetic acid (99mTc-DTPA) renal scan method as the standard for comparison. The Receiver Operating Characteristics (ROC) analysis was used to evaluate the diagnostic accuracy of the filtration rate. Results: A significant association was observed (p=0.0001) among both the estimates which were equivocal when compared with measured iGFR, SCr and Cys-C based GFR estimate. A greater difference of Area Under the Curve (AUC) was observed between SCr (0.765±0.07) and Cys-C (0.569±0.09) (p=0.04) in the ROC analysis at a creatinine clearance &lt;60 mL/min/m2. conclusion: The SCr and Cys-C based formulae has equivocal performance in estimating GFR. SCr could be a better marker to estimate GFR among patients with Cr clearance &lt;60 mL/min/m2.

Differential contribution of the factors determining long-term renal function after partial nephrectomy over time

PurposeTo define how much of renal function was determined by the preserved renal parenchymal volume and the ischemic insult during partial nephrectomy (PN) long after surgery. MethodsWe analyzed the data of 530 consecutive patients who had undergone PN. For all patients, renal function was measured preoperatively and again at 3 postoperative months, then annually using 99mTc-diethylenetriaminepentaacetic acid renal scan. Perioperative variables potentially affecting the long-term ipsilateral glomerular filtration rate (GFR) and their time-varying contribution were assessed using a linear mixed model. ResultsThe mean preoperative ipsilateral GFR was 42.9 ml/min, which decreased by 27.3% at 3 months but began to recover thereafter continuing until 4 years (Δ% GFR at 1, 2, 3, 4, and 5 years: 22.3%, 18.5%, 14.7%, 10.0%, and 9.6%, respectively). Parenchymal volume reduction and ischemic time were significantly associated with postoperative ipsilateral GFR throughout observation period unvarying with time. Diabetes and proteinuria were not significant determinants of ipsilateral function at 3 months but became significant at 5 years. In multivariate analysis regarding recovery slope, volume reduction (β = −0.026, SE 0.006, P < 0.0001), preoperative ipsilateral GFR (β = −0.021, SE 0.007, P = 0.0012), proteinuria (β = −0.942, SE 0.372, P = 0.0116), and diabetes (β = −0.396, SE 0.197, P = 0.0447) were independently significant. ConclusionIpsilateral renal function continued to improve until 5 years after PN. Parenchymal volume loss was the major determinant and its impact on long-term ipsilateral renal function remained constant while ischemic time affected early GFR reduction with its impact diminishing over time. Patient-related factors including diabetes and proteinuria gained significance over time and became independent determinants of recovery slope.

Vesicoureteral Reflux and Renal Scarring in Children with Acute Pyelonephritis: the Role of Late 6-month Dimercaptosuccinic Acid Renal Scan

Purpose The aim of this study is to evaluate the clinical utility of late 6-month dimercapto-succinic acid (DMSA) renal scan in predicting vesicoureteral reflux (VUR) and long-lasting renal scars in children with first acute pyelonephritis (APN). Methods A retrospective case study of children admitted with APN from January 2010 to July 2017 was performed. The study included patients with voiding cystourethrography (VCUG) and acute and late 6-month DMSA scan. We analyzed the clinical, laboratory and imaging findings of patients with and without late cortical defects at 6 months and those with or without VUR. Results Among 145 children with APN, 50 (34.5%) had cortical defects on the late DMSA renal scan and 60 (41.4%) showed VUR. Thirteen of 38 (34.2%) children undergoing 18-month DMSA renal scan showed a long-lasting renal scars. Compared with children without late cortical defects, patients with late 6-month cortical defects had a higher incidence of VUR and long-lasting renal scars, and relapse of UTI (all P<0.05). In a multivariable analysis, both high-grade VUR and relapse of UTI were independently correlated with the presence of late 6-month cortical defects (P<0.05). Late cortical defects and relapse of UTI were also associated with the presence of VUR (P<0.05). Only the late 6-mo cortical defects was an independent predictor of long-lasting renal scars in children with APN (P<0.05). Conclusion An abnormal late 6-month DMSA renal scan may be useful in identifying VUR and long-lasting renal scars in children diagnosed with APN. Key words: Renal scarring; Acute pyelonephritis; Vesicoureteral reflux; Dimercaptosuccinic acid renal scan