Split Kidney Function Research Articles

Quantitative assessment of kidney split function and mean transit time in healthy patients using dynamic 18F-FDG PET/MRI studies with denoising and deconvolution methods making use of Legendre polynomials

PurposeOur objective was to assess a deconvolution and denoising technique based on Legendre polynomials compared to matrix deconvolution on dynamic 18F-FDG renography of healthy patients.MethodThe study was carried out and compared to the data of 24 healthy patients from a published study who underwent examinations with 99mTc-MAG3 planar scintigraphy and 18F-FDG PET/MRI. Due to corruption issues in some data used in the published article, post-publication measurements were provided. We have been warned that post-publication data were treated differently. The smoothing method switched from Bezier to Savitzky–Golay and the deconvolution from matrix-based (with Tikhonov Regularization) to Richardson–Lucy. A comparison of the split function and mean transit times of the published and post-publication data against our method based on Legendre polynomials was performed.ResultsFor split function, we only observed a good agreement between the processing methods for the 99mTc-MAG3 and the post-published data. No correlation was found between the split functions obtained on the 99mTc-MAG3 and the 18F-FDG, contrary to the published study. However, all calculated split function values for 18F-FDG and 99mTc-MAG3 were within the established normal range. For the mean transit time, the correlation was moderate with published data and very good with the post-publication measurements for both 99mTc-MAG3 and 18F-FDG. Bias of the Bland–Altman analysis of the mean transit times for 99mTc-MAG3 versus 18F-FDG was 1.1 min (SD 1.7 min) for the published data, − 0.11 min (SD 1.9 min) for the post-publication results and .05 min (SD 1.9 min) for our method.ConclusionsThe processing methods used in the original publication and in the post-publication work were quite complex and required adaptation of the fitting parameters for each individual and each type of examination. Our method did not require any specific adjustment; the same unmodified and fully automated algorithm was successfully applied to all data.

Assessing asymmetrical kidney function in living donors: a retrospective cohort study on CT metrics

BackgroundLive donor kidney transplantation is the preferred kidney replacement therapy for eligible patients but requires thorough donor evaluation to minimise risks. Contemporary guidelines recommend split kidney function measurement in living donors only when there is a significant kidney size discrepancy, yet the evidence for this is poor, and practice varies nationally. This study evaluates the efficacy of CT-derived kidney metrics in detecting significant functional asymmetry.MethodsWe conducted a retrospective cohort analysis of 123 prospective living kidney donors at a regional transplant centre from June 2011 to October 2014, utilising CT to determine kidney and cortical volumes and lengths. Asymmetric kidney function (AKF), defined by > 10% function difference on DMSA scans, was correlated with CT measurements to calculate the diagnostic accuracy of current guidelines.ResultsAmong the prospective donors, the median age was 42 years, and 59.3% were female. The median split kidney function difference was 4%, with 25 individuals exhibiting > 10% AKF. Kidney length discrepancy proved to be a poor indicator of AKF (sensitivity: 28%, specificity: 84%). While negative predictive values for cortical and kidney volumes were high (96% and 93%, respectively), sensitivity was low, and specificity and positive predictive value did not meet satisfactory thresholds.ConclusionsCT-derived metrics of kidney length, cortical, and total volume show limited sensitivity and specificity in identifying significant AKF. These findings provide evidence to support revised guideline development in the assessment of living kidney donors.

Automated Analysis of Split Kidney Function from CT Scans Using Deep Learning and Delta Radiomics.

Background: Differential kidney function assessment is an important part of preoperative evaluation of various urological interventions. It is obtained through dedicated nuclear medical imaging and is not yet implemented through conventional Imaging. Objective: We assess if differential kidney function can be obtained through evaluation of contrast-enhanced computed tomography(CT) using a combination of deep learning and (2D and 3D) radiomic features. Methods: All patients who underwent kidney nuclear scanning at Mayo Clinic sites between 2018-2022 were collected. CT scans of the kidneys were obtained within a 3-month interval before or after the nuclear scans were extracted. Patients who underwent a urological or radiological intervention within this time frame were excluded. A segmentation model was used to segment both kidneys. 2D and 3D radiomics features were extracted and compared between the two kidneys to compute delta radiomics and assess its ability to predict differential kidney function. Performance was reported using receiver operating characteristics, sensitivity, and specificity. Results: Studies from Arizona & Rochester formed our internal dataset (n = 1,159). Studies from Florida were separately processed as an external test set to validate generalizability. We obtained 323 studies from our internal sites and 39 studies from external sites. The best results were obtained by a random forest model trained on 3D delta radiomics features. This model achieved an area under curve (AUC) of 0.85 and 0.81 on internal and external test sets, while specificity and sensitivity were 0.84,0.68 on the internal set, 0.70, and 0.65 on the external set. Conclusion: This proposed automated pipeline can derive important differential kidney function information from contrast-enhanced CT and reduce the need for dedicated nuclear scans for early-stage differential kidney functional assessment. Clinical Impact: We establish a machine learning methodology for assessing differential kidney function from routine CT without the need for expensive and radioactive nuclear medicine scans.

Non-contrast-enhanced magnetic resonance urography for measuring split kidney function in pediatric patients with hydronephrosis: comparison with renal scintigraphy.

Split kidney function (SKF) is critical for treatment decision in pediatric patients with hydronephrosis and is commonly measured using renal scintigraphy (RS). Non-contrast-enhanced magnetic resonance urography (NCE-MRU) is increasingly used in clinical practice. This study aimed to investigate the feasibility of using NCE-MRU as an alternative to estimate SKF in pediatric patients with hydronephrosis, compared to RS. Seventy-five pediatric patients with hydronephrosis were included in this retrospective study. All patients underwent NCE-MRU and RS within 2weeks. Kidney parenchyma volume (KPV) and texture analysis parameters were obtained from T2-weighted (T2WI) in NCE-MRU. The calculated split KPV (SKPV) percent and texture analysis parameters percent of left kidney were compared with the RS-determined SKF. SKPV showed a significant positive correlation with SKF (r = 0.88, p < 0.001), while inhomogeneity was negatively correlated with SKF (r = - 0.68, p < 0.001). The uncorrected and corrected prediction models of SKF were established using simple and multiple linear regression. Bland-Altman plots demonstrated good agreement of both predictive models. The residual sum of squares of the corrected prediction model was lower than that of the uncorrected model (0.283 vs. 0.314) but not statistically significant (p = 0.662). Subgroup analysis based on different MR machines showed correlation coefficients of 0.85, 0.95, and 0.94 between SKF and SKPV for three different scanners, respectively (p < 0.05 for all). NCE-MRU can be used as an alternative method for estimating SKF in pediatric patients with hydronephrosis when comparing with RS. Specifically, SKPV proves to be a simple and universally applicable indicator for predicting SKF.

Preoperative Renal Parenchyma Volume as a Predictor of Kidney Function Following Nephrectomy of Complex Renal Masses

BackgroundThe von Hippel-Lindau disease (VHL) is a hereditary cancer syndrome with multifocal, bilateral cysts and solid tumors of the kidney. Surgical management may include multiple extirpative surgeries, which ultimately results in parenchymal volume loss and subsequent renal function decline. Recent studies have utilized parenchyma volume as an estimate of renal function prior to surgery for renal cell carcinoma; however, it is not yet validated for surgically altered kidneys with multifocal masses and complex cysts such as are present in VHL. ObjectiveWe sought to validate a magnetic resonance imaging (MRI)-based volumetric analysis with mercaptoacetyltriglycine (MAG-3) renogram and postoperative renal function. Design, setting, and participantsWe identified patients undergoing renal surgery at the National Cancer Institute from 2015 to 2020 with preoperative MRI. Renal tumors, cysts, and parenchyma of the operated kidney were segmented manually using ITK-SNAP software. Outcome measurements and statistical analysisSerum creatinine and urinalysis were assessed preoperatively, and at 3- and 12-mo follow-up time points. Estimated glomerular filtration rate (eGFR) was calculated using serum creatinine-based CKD-EPI 2021 equation. A statistical analysis was conducted on R Studio version 4.1.1. Results and limitationsPreoperative MRI scans of 113 VHL patients (56% male, median age 48 yr) were evaluated between 2015 and 2021. Twelve (10.6%) patients had a solitary kidney at the time of surgery; 59 (52%) patients had at least one previous partial nephrectomy on the renal unit. Patients had a median of three (interquartile range [IQR]: 2–5) tumors and five (IQR: 0–13) cysts per kidney on imaging. The median preoperative GFR was 70 ml/min/1.73 m2 (IQR: 58–89). Preoperative split renal function derived from MAG-3 studies and MRI split renal volume were significantly correlated (r = 0.848, p < 0.001). On the multivariable analysis, total preoperative parenchymal volume, solitary kidney, and preoperative eGFR were significant independent predictors of 12-mo eGFR. When only considering patients with two kidneys undergoing partial nephrectomy, preoperative parenchymal volume and eGFR remained significant predictors of 12-mo eGFR. ConclusionsA parenchyma volume analysis on preoperative MRI correlates well with renogram split function and can predict long-term renal function with added benefit of anatomic detail and ease of application. Patient summaryPrior to kidney surgery, it is important to understand the contribution of each kidney to overall kidney function. Nuclear medicine scans are currently used to measure split kidney function. We demonstrated that kidney volumes on preoperative magnetic resonance imaging can also be used to estimate split kidney function before surgery, while also providing essential details of tumor and kidney anatomy.

Assessment of the kidney functional state prior and after partial nephrectomy for a unilateral tumor using mathematical processing of computed tomography data with contrast enhancement

Background. According to the contemporary data available contrast-enhanced computed tomography can be used to assess total and split kidney function. The Urology Clinic of the I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia (Sechenov University) utilizes mathematical processing of computed tomography data for the assessment of split kidney function.Aim. To evaluate the effect of main renal artery clamping (warm ischemia time) during partial nephrectomy for a unilateral tumor on the kidney function.Materials and methods. 33 patients of both sexes who underwent partial nephrectomy for unilateral kidney tumor were enrolled in the study. Prior to and 3–6 months after the surgery, 3D glomerular filtration rate (GFR), 3D perfusion, 3D volume of the renal parenchyma were evaluated by mathematical processing of computed tomography data with contrast enhancement. As well as that the dynamics of the total GFR (CKD-EPI equation) and total volume of the kidneys were assessed.Results. No significant changes were registered for both general functional renal parameters (creatinine level, total GFR, total volume of functioning renal parenchyma) and split 3D GFR. There were significant differences in 3D perfusion and kidney parenchyma volume prior and after partial nephrectomy.Conclusion. The results of the research highlight good reserve capacity the kidneys after partial nephrectomy with main renal artery clamping. The evidence that the non-operated kidney takes over the function of the resected kidney is based on the fact that there is an increase in its perfusion and volume of the kidney in the postoperative period. This state can also be regarded as a redistribution of functional loads between the kidneys, which is an adaptive mechanism in the postoperative period.

Robot-Assisted Laparoscopic Ureteroureterostomy of an Obstructive Retrocaval Ureter

Clinical History: A 32-year-old woman without significant medical history presented with incidentally found right severe hydronephrosis from a computed tomography scan after car accident. Her symptoms include only intermittent right flank pain. She has no dysuria or hematuria. Physical Examination: Examination was notable for right-sided costovertebral angle tenderness. Diagnosis: A computed tomography urogram scan was performed, which revealed severe right hydronephrosis with abrupt transition point at proximal ureter. The transition point was located posterior to the inferior vena cava, consistent with retrocaval ureter anatomy. Renal nucleotide scan showed 40% right kidney split function as well as a t1/2 of 35 minutes in right kidney, suggesting obstruction. Intervention: Given symptomatic pain, radiologic evidence of ureteral obstruction, good residual right renal function, and performance status, decision was made to perform a right robot-assisted laparoscopic ureteroureterostomy. Follow-up/Outcomes: Patient tolerated the procedure well and was discharged home the morning after surgery with drain removed. She had prompt return of daily activities and complete resolution of flank pain. Her ureteral stent was removed in clinic 6 weeks after the surgery. Repeat renal nucleotide scan 3 months after the surgery demonstrated resolution of obstruction with new t1/2 of 8.7 minutes. Patient Consent Statement: The author(s) have received and archived patient consent for video recording/publication in advance of video recording of procedure. The authors have no conflicts of interest that may alter the results of this study. Runtime of video: 4 mins 28 secs

Relationship Between Sporadic Renal Cysts and Renal Function Detected by Isotope Renography in Type 2 Diabetes.

PurposeThis study aimed to reveal the relationship between the volume of sporadic renal cysts and renal function in patients with type 2 diabetes (T2D).Materials and MethodsOne hundred and seventy-one patients that underwent renal imaging and other routine examinations at the Shanghai Pudong Hospital were included in this study. The Gates’ method of glomerular filtration rate (GFR) was measured by 99mTc-DTPA renal dynamic imaging in addition to the eGFR, calculated by the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI).ResultsOur results showed that BMI, total iGFR, and eGFR showed significant differences between patients with T2D with or without SRC (p < 0.05). Spearman correlation analysis showed that cyst volume was positively correlated with Scr and gender but not iGFR (p > 0.05). The total iGFR positively correlated with eGFR (r = 0.83, p < 0.0001) and negatively with Scr (r = −0.78, p < 0.0001), age (r = −0.43, p < 0.0001), duration of T2D (r = −0.25, p = 0.001), and BMI (r = −0.21, p = 0.006) but not gender (r = −0.03, p = 0.668). The multilinear regression model revealed that gender (β = 0.346, p < 0.001), iGFR (β = −0.705, p < 0.001), and serum uric acid (β = 0.195, p = 0.032) were independent predictors of Scr. Moreover, we observed a significant increase in Scr in males (p < 0.05). Finally, we found that the split kidney function reflected by iGFR and related parameters such as time to peak (PTT) and half time of excretion (excrete t1/2) did not mutually distinguish from each other significantly whether they are measured in patients with renal cysts or in those without renal cysts (p > 0.05).ConclusionOur preliminary results suggest that in T2D, SRCs may be a renal complication of diabetic nephropathy. Although we found that the patients with renal cysts may display reduced iGFR, the volume of simple cysts seems not to exacerbate renal insufficiency. Isotope renography is a useful tool to evaluate the split kidney functions in diabetic patients who acquire single-side cysts.

Comparison of CT volumetry versus nuclear renography for predicting remaining kidney function after uninephrectomy in living kidney donors

Computed tomography (CT) and nuclear renography are used to determine kidney procurement in living kidney donors (LKDs). The present study investigated which modality better predicts kidney function after donation. This study included 835 LKDs and they were divided into two subgroups based on whether the left–right dominance of kidney volume was concordant with kidney function (concordant group) or not (discordant group). The predictive value for post-donation kidney function between the two imaging modalities was compared at 1 month, 6 months, and > 1 year in total cohort, concordant, and discordant groups. Split kidney function (SKF) measured by both modalities showed significant correlation with each other at baseline. SKFs of remaining kidney measured using both modalities before donation showed significant correlation with eGFR (estimated glomerular filtration rate) after donation in the total cohort group and two subgroups, respectively. CT volumetry was superior to nuclear renography for predicting post-donation kidney function in the total cohort group and both subgroups. In the discordant subgroup, a higher tendency of kidney function recovery was observed when kidney procurement was determined based on CT volumetry. In conclusion, CT volumetry is preferred when determining procurement strategy especially when discordance is found between the two imaging modalities.

Mathematical postprocessing analysis of contrast-enhanced computed tomography data of the kidneys in evaluation of split renal function in patients with kidney stone disease

Introduction. An original research work was performed to assess split kidney function by glomerular filtration rate (GFR) with mathematical analysis of the kidneys computed tomography (CT) data in patients with kidney stone disease (KSD). Objective was to evaluate the GFR and the parenchyma structure of each kidney and identify the possible patterns of contrast medium intrarenal transport with mathematical analysis of the kidneys CT data in patients with KSD.Materials and methods. Data of 27 patients of both genders with KSD were retrospectively analyzed. To evaluate GFR separately for each kidney we analyzed the data of contrast-enhanced CT (GFR reference values are 0.55 % of contrast medium per second). Inclusion criteria are as follows: 1) newly diagnosed SKD; 2) stone size ≤1,5-2,0 cm, no obstruction of the urine flow registered; 3) no kidney or upper urinary tract surgical history; 4) age - ≤45 years; 5) no severe chronic diseases. All of these allowed to minimize influence of any other disorders on split renal function except for SKD and conduct per se research.Results. The mathematic analysis of the contrast-enhanced CT data revealed GFR changes in 26 (96.3 %) out of 27 patients. Hyperfiltration was found in 12 (44.4 %) patients: right kidney GFR - 0.6-0.77 %, mean value - 0.65 %; left kidney GFR - 0.59-0.79 %, mean value - 0.67 %. Hypofiltration was found in 13 (48.1 %) patients: right kidney GFR - 0.2-0.54 %, mean value - 0.37 %; left kidney GFR - 0.2-0.53 %, mean value - 0.4 %. The GFR values significantly differed between the groups both for the right (p = 0.000014) and left (p = 0.000045) kidneys. We found no significant age-related difference between the groups (p = 0.895). As well as that no significant differences in Resistance Index both in magistral (right kidney: p = 0.221; left kidney: p = 0.850) and segmental (right kidney: p = 0.306; left kidney: p = 0.957) arteries between the groups with hyperfiltration and hypofiltration were observed. One patient demonstrated no changes in GFR, and the other one had hyperfiltration (0,62 %) in one kidney and hypofiltration (0,48 %) in another.Conclusion. Most of the patients (92.6 %) with SKD demonstrate GFR changes (either hyperfiltration or hypofiltration) that may indicate the disturbed intrarenal blood and urine flow through the kidney.

Clinical and radiographic outcomes following salvage intervention for ureteropelvic junction obstruction.

ABSTRACTPurpose:We aimed to assess failure rates of salvage interventions and changes in split kidney function (SKF) following failed primary repair of ureteropelvic junction obstruction (UPJO).Materials and Methods:A retrospective review of adult patients at an academic medical center who underwent salvage intervention following primary treatment for UPJO was performed. Symptomatic failure was defined as significant flank pain. Radiographic failure was defined as no improvement in drainage or a decrease in SKF by ≥7%. Overall failure, the primary outcome, was defined as symptomatic failure, radiographic failure, or both.Results:Between 2008-2017, 34 patients (median age 38 years, 50% men) met study criteria. UPJO management was primary pyeloplasty/secondary endopyelotomy for 21/34 (62%), primary pyeloplasty/secondary pyeloplasty for 6/34 (18%), and primary endopyelotomy/secondary pyeloplasty for 7/34 (21%). Median follow-up was 3.3 years following secondary intervention. Patients undergoing primary pyeloplasty/secondary endopyelotomy had significantly higher overall failure than those undergoing primary pyeloplasty/secondary pyeloplasty (16/21 [76%] vs. 1/6 [17%], p=0.015). Among patients undergoing secondary endopyelotomy, presence of a stricture on retrograde pyelogram, stricture length, and SKF were not associated with symptomatic, radiographic, or overall failure. Serial renography was performed for 28/34 (82%) patients and 2/28 (7%) had a significant decline in SKF.Conclusions:Following failed primary pyeloplasty, secondary endopyelotomy had a greater overall failure rate than secondary pyeloplasty. No radiographic features assessed were associated with secondary endopyelotomy failure. Secondary intervention overall failure rates were higher than reported in the literature. Unique to this study, serial renography demonstrated that significant functional loss was overall infrequent.

CT-measured Cortical Volume Ratio Is an Accurate Alternative to Nuclear Medicine Split Scan Ratio Among Living Kidney Donors.

The 125I-iothalamate clearance and 99mTc diethylenetriamine-pentaacetic acid (99mTc-DTPA) split scan nuclear medicine studies are used among living kidney donor candidates to determine measured glomerular filtration rate (mGFR) and split scan ratio (SSR). The computerized tomography-derived cortical volume ratio (CVR) is a novel measurement of split kidney function and can be combined with predonation estimated GFR (eGFR) or mGFR to predict postdonation kidney function. Whether predonation SSR predicts postdonation kidney function better than predonation CVR and whether predonation mGFR provides additional information beyond predonation eGFR are unknown. We performed a single-center retrospective analysis of 204 patients who underwent kidney donation between June 2015 and March 2019. The primary outcome was 1-y postdonation eGFR. Model bases were created from a measure of predonation kidney function (mGFR or eGFR) multiplied by the proportion that each nondonated kidney contributed to predonation kidney function (SSR or CVR). Multivariable elastic net regression with 1000 repetitions was used to determine the mean and 95% confidence interval of R2, root mean square error (RMSE), and proportion overprediction ≥15 mL/min/1.73 m2 between models. In validation cohorts, eGFR-CVR models performed best (R2, 0.547; RMSE, 9.2 mL/min/1.73 m2, proportion overprediction 3.1%), whereas mGFR-SSR models performed worst (R2, 0.360; RMSE, 10.9 mL/min/1.73 m2, proportion overprediction 7.2%) (P < 0.001 for all comparisons). These findings suggest that predonation CVR may serve as an acceptable alternative to SSR during donor evaluation and furthermore, that a model based on CVR and predonation eGFR may be superior to other methods.

Compensatory Hypertrophy in Paediatric Patients with a Unilateral Ureteropelvic Junction Obstruction

BackgroundCompensatory hypertrophy is common in children with solitary functioning kidney, but it is unknown whether it also develops in children with unilateral partial reduction of kidney function. ObjectiveThe aim of this study was to assess whether children with a unilateral ureteropelvic junction obstruction (UPJO) show compensatory growth of the unaffected kidney. Furthermore, we investigated whether the length of the unaffected kidney was related to the degree of split kidney function lost and other possible risk factors. Lastly, we studied a possible relationship with signs of kidney injury. Design, setting, and participantsWe retrospectively analysed clinical information from 194 children with a unilateral UPJO who participated in the Aetiologic research into Genetic and Occupational/environmental Risk factors for Anomalies in children (AGORA) data- and biobank. Data on kidney length, split kidney function, and other factors possibly associated with kidney length were extracted from electronic patient records. Outcome measurements and statistical analysisPearson’s correlation coefficients between the split kidney function and unaffected kidney length were calculated. Multivariable logistic regression analyses were performed to identify factors associated with kidney length and signs of kidney injury. Results and limitationsMost children with a UPJO had an unaffected kidney length above the reference for age at the end of follow-up (median age 6.5 yr). A correlation with split kidney function was present only in children with a split kidney function of ≥60% in the unaffected kidney (r = 0.41). Aside from split kidney function, UPJO side was the only determinant of kidney length, while no associations between kidney length and kidney injury were identified. ConclusionsCompensatory growth was visible in most children with a UPJO after sufficient follow-up time and was correlated with split kidney function in children with a severe UPJO. Contralateral kidney length provided no clear prognostic value for developing kidney injury. Studies with more patients and additional biomarkers of kidney injury are needed to further personalise care. Patient summaryChildren with obstruction of urine outflow in one kidney often had a larger contralateral kidney. However, the size of this kidney could not be used to predict which children would develop kidney injury.

Potential benefits of functional magnetic resonance urography (fMRU) over MAG3 renal scan in children with obstructive uropathy

Functional renal imaging, most commonly with MAG3 nuclear medicine renal scan, is recommended in the evaluation of children with urinary tract dilation (UTD) suspected of obstructive uropathy. Alternatively, renal function can be evaluated with functional Magnetic Resonance Urography (fMRU), which has superior anatomic detail. However, there are not enough data comparing both methods' equivalency. In this study, we compare the functional and obstruction parameters of fMRU and MAG3 in a pediatric cohort presenting with obstructive uropathy. This is an IRB-approved retrospective review of all children undergoing fMRU at a single, free-standing children's hospital between May 2008 and September 2017. Patients who also underwent a MAG3 renal scan within 6 months and who had no interval surgical intervention were included in the study. Bladder catheterization was performed prior to both imaging studies. 735 children had 988 fMRU studies performed during the study period. 37 unique patients (13 girls and 24 boys) with median age of 6 months (range: 2 mo-19y) were included in the final sample. Median time interval between studies was 70 days (range 6-179 days). The majority of participants (26/37, 70.3%) presented with UTD P3 and had diagnosis of uretero-pelvic junction obstruction (UPJO) in 21/37. Differential renal function (DRF) was used to group 10 fMRU and 9 MAG3 patients as normal; 9 fMRU and 11 MAG3 as mild; 11 fMRU and 6 MAG3 as moderate; and 7 fMRU and 6 MAG3 as severe; Wilcoxon signed-rank test (p=0.5106). Results were similar for DRF among patients with and without duplex kidneys. In the analysis of obstruction, using reference standard T½ MAG3≥20min, a greater or equal than 6min renal transit time (RTT) from fMRU showed a specificity of 94%, a sensitivity of 62%, and an AUC of 0.827. The differential renal function determined by MAG3 and fMRU in children was not statistically different, therefore we concluded that it was similar and potentially equivalent. Better correlation was shown in patients who had normal split kidney function. While the tests are clinically equivalent, the variability of DRF within each clinical category (i.e., normal, mild, moderate, severe) is not surprising, because MAG3 does not clearly differentiate the dilated collecting system from the functional parenchymal tissue, while fMRU does. Using MAG3 as the gold standard, fMRU was 94.74% specific and 5% more sensitive in detecting UPJO with a RTT of 6min vs. 8min.

The impact of measuring split kidney function on post-donation kidney function: A retrospective cohort study

BackgroundStudies have reported agreement between computed tomography (CT) and renography for the determination of split kidney function. However, their correlation with post-donation kidney function remains unclear. We compared CT measurements with renography in assessment of split kidney function (SKF) and their correlations with post-donation kidney function.MethodsA single-centre, retrospective cohort study of 248 donors from January 1, 2009-July 31, 2019 were assessed. Pearson correlations were used to assess post-donation kidney function with renography and CT-based measurements. Furthermore, we examined high risk groups with SKF difference greater than 10% on renography and donors with post-donation eGFR less than 60 mL/min/1.73m2.Results62% of donors were women with a mean (standard deviation) pre-donation eGFR 99 (20) and post-donation eGFR 67 (22) mL/min/1.73m2 at 31 months of follow-up. Post-donation kidney function was poorly correlated with both CT-based measurements and renography, including the subgroup of donors with post-donation eGFR less than 60 mL/min/1.73m2 (r less than 0.4 for all). There was agreement between CT-based measurements and renography for SKF determination (Bland-Altman agreement [bias, 95% limits of agreement] for renography vs: CT volume, 0.76%, -7.60–9.15%; modified ellipsoid,1.01%, -8.38–10.42%; CC dimension, 0.44%, -7.06–7.94); however, CT missed SKF greater than 10% found by renography in 20 out 26 (77%) of donors.ConclusionsIn a single centre study of 248 living donors, we found no correlation between CT or renography and post-donation eGFR. Further research is needed to determine optimal ways to predict remaining kidney function after donation.

The outcome of kidney transplant from living donors with pelvi-ureteric junction dysfunction

PurposeTo assess the effect of receiving a kidney with PUJ dysfunction on the recipient renal graft function.Methodology198 patients, who underwent renal transplantation from 1st January 2004 to 31st December 2014 in a single Center in the North West of England, were retrospectively reviewed using a computerized database. Split kidney function and the PUJ dysfunction for the donors were assessed using Tc-99 m MAG3 renogram. Each recipient with PUJ dysfunction was matched with a control recipient by age, gender, and number of days after transplantation. Both groups were followed up for 3.5 years post-transplantation.ResultsOf the 198 recipients included in the study, 19 recipients received kidneys from donors with PUJ dysfunction. Prevalence of PUJ dysfunction was 9.5% and it was more common in males than females. There was no difference between the case group and the control group in terms of age, gender, and follow-up time post-transplantation. There was also no difference between the case group and the control group in mean creatinine (130 µmol/l and 138 µmol/l respectively, p = 0.305) or the mean eGFR (48.6 ml/min and 47.5 ml/min respectively, p = 0.054) at 3.5 year post-kidney transplantation.ConclusionThis study showed that PUJ dysfunction of renal allograft has a negligible effect on graft function over 3.5 years period post-transplantation. A prospective randomized trial is needed to test these findings. In the presence of widened gap between demand and supply in renal transplantation, PUJ dysfunction in potential donors should not preclude them from donation.

Assessment of the kidney function parameters split function, mean transit time, and outflow efficiency using dynamic FDG-PET/MRI in healthy subjects

BackgroundTraditionally, isotope nephrography is considered as the method of choice to assess kidney function parameters in nuclear medicine. We propose a novel approach to determine the split function (SF), mean transit time (MTT), and outflow efficiency (OE) with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) dynamic positron emission tomography (PET).Materials and methodsHealthy adult subjects underwent dynamic simultaneous FDG-PET and magnetic resonance imaging (PET/MRI). Time-activity curves (TACs) of total kidneys, renal cortices, and the aorta were prospectively obtained from dynamic PET series. MRI images were used for anatomical correlation. The same individuals were subjected to dynamic renal Technetium-99 m-mercaptoacetyltriglycine (MAG3) scintigraphy and TACs of kidneys; the perirenal background and the left ventricle were determined. SF was calculated on the basis of integrals over the TACs, MTT was determined from renal retention functions after deconvolution analysis, and OE was determined from MTT. Values obtained from PET series were compared with scintigraphic parameters, which served as the reference.ResultsTwenty-four subjects underwent both examinations. Total kidney SF, MTT, and OE as estimated by dynamic PET/MRI correlated to their reference values by r = 0.75, r = 0.74 and r = 0.81, respectively, with significant difference (p < 0.0001) between the means of MTT and OE. No correlations were found for cortex FDG values.ConclusionsThe study proofs the concept that SF, MTT, and OE can be estimated with dynamic FDG PET/MRI scans in healthy kidneys. This has advantages for patients receiving a routine PET/MRI scan, as kidney parameters can be estimated simultaneously to functional and morphological imaging with high accuracy.

CT volumetry is superior to nuclear renography for prediction of residual kidney function in living donors.

Living kidney donor evaluation commonly includes nuclear renography to assess split kidney function and computed tomography (CT) scan to evaluate anatomy. To streamline donor workup and minimize exposure to radioisotopes, we sought to assess the feasibility of using proportional kidney volume from CT volumetry in lieu of nuclear renography. We examined the correlation between techniques and assessed their ability to predict residual postoperative kidney function following live donor nephrectomy. In a cohort of 224 live kidney donors, we compared proportional kidney volume derived by CT volumetry with split kidney function derived from nuclear renography and found only modest correlation (left kidney R(2) =26.2%, right kidney R(2) =26.7%). In a subset of 88 live kidney donors with serum creatinine measured 6months postoperatively, we compared observed estimated glomerular filtration rate (eGFR) at 6months with predicted eGFR from preoperative imaging. Compared to nuclear renography, CT volumetry more closely approximated actual observed postoperative eGFR for Chronic Kidney Disease Epidemiology Collaboration (J-test: P=.02, Cox-Pesaran test: P=.01) and Mayo formulas (J-test: P=.004, Cox-Pesaran test: P<.001). These observations support the use of CT volumetry for estimation of split kidney function in healthy individuals with normal kidney function and morphology.

MP29-20 COMPARISON OF CT-MEASURED SPLIT RENAL VOLUME AND SPLIT RENAL FUNCTION BY DTPA CINTIGRAPHY FOR THE PREDICTION OF 12 MONTHS KIDNEY GRAFT FUNCTION

You have accessJournal of UrologyTransplantation & Vascular Surgery: Renal Transplantation & Vascular Surgery I1 Apr 2016MP29-20 COMPARISON OF CT-MEASURED SPLIT RENAL VOLUME AND SPLIT RENAL FUNCTION BY DTPA CINTIGRAPHY FOR THE PREDICTION OF 12 MONTHS KIDNEY GRAFT FUNCTION Diogo Gil-Sousa, Jorge Dias, Daniel Oliveira-Reis, Diogo Carneiro, Jorge Malheiro, Manuela Almeida, Leonídio Dias, António Castro-Henriques, José Soares, Avelino Fraga, and Miguel Silva Ramos Diogo Gil-SousaDiogo Gil-Sousa More articles by this author , Jorge DiasJorge Dias More articles by this author , Daniel Oliveira-ReisDaniel Oliveira-Reis More articles by this author , Diogo CarneiroDiogo Carneiro More articles by this author , Jorge MalheiroJorge Malheiro More articles by this author , Manuela AlmeidaManuela Almeida More articles by this author , Leonídio DiasLeonídio Dias More articles by this author , António Castro-HenriquesAntónio Castro-Henriques More articles by this author , José SoaresJosé Soares More articles by this author , Avelino FragaAvelino Fraga More articles by this author , and Miguel Silva RamosMiguel Silva Ramos More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1104AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Living donor kidney transplantation (KT) has broadened the availability of kidney grafts, allowing a partial response to the growing number of patients with end-stage renal disease for whom KT is indicated. Although living donor KT evaluation is paramount to maximize kidney graft function, no clear international guidelines exist. We aimed to evaluate and correlate the living donor DTPA-measured and CT-measured split renal function in the prediction of kidney graft function at 12 months. METHODS Retrospective analysis of 110 living donor KT pairs performed by a single academic institution between May 2008 and September 2014. All living donors underwent preoperative DTPA Cintigraphy and renal imaging with 3D helicoidal CT. Renal volumes were obtained for each donor using the voxel counting technique. Pre-KT donor eGFR was calculated using MDRD equation, and recipient graft function at 12-months was estimated by MDRD formula. Split renal function was determined by DTPA-measured split function (%DTPA) and by CT-measured split volume (%TC). Correlation between both living donor split renal function approaches and graft function at 12 months was performed using Pearson Correlation and Receiver Operating Characteristic (ROC) curves. RESULTS Mean donor and recipient age were 47,1±10,4 and 39.2±13,2 years, respectively. Donor mean total kidney volume was 318,8±42,4cc/1,73m2, with a mean CT-measured transplanted kidney split volume of 51,0±4,0%. Mean DTPA-measured transplanted kidney split function was 49,3±3,6%. Pearson Correlation Coefficient (r) between the pre-transplant split renal function of the transplanted kidney (calculated by %CT or %DTPA and MDRD eGFR) and graft function at 12 months, showed a strong correlation for both split renal function measurement techniques, with a trend to better predictive value for CT: r (eGFR-DTPA% transplanted Kidney) 0,350 Vs. r (eGFR-CT% transplanted Kidney) 0,363. In addition, a cut-off of <50 mL/min/1.73 m2 was used to define impaired kidney graft function at 12 months. Performing a ROC analyses between the pre-transplantation split renal function (according to %DTPA or %CT and MDRD eGFR) and impaired kidney graft function, we observe that all split function estimates were highly predictive of recipient graft function outcome (p<0,001), though %TC estimates presented the highest AUCs (AUC eGFR(MDRD)*%DTPA=0,778 Vs. AUC eGFR(MDRD)*%TC=0,822). CONCLUSIONS Preoperative CT-measured split renal volume proved to be as correlated with recipient eGFR at 12 months as split renal function by DTPA. CT-based split function has shown to be a slightly better predictor of impaired kidney graft function than DTPA-based split function. CT split renal volume evaluation seems to bear the potential to substitute current methods, as renal cintigraphy, in the evaluation of pre-transplant split renal function, allowing for a better allocation of means in living-donor KT. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e388 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Diogo Gil-Sousa More articles by this author Jorge Dias More articles by this author Daniel Oliveira-Reis More articles by this author Diogo Carneiro More articles by this author Jorge Malheiro More articles by this author Manuela Almeida More articles by this author Leonídio Dias More articles by this author António Castro-Henriques More articles by this author José Soares More articles by this author Avelino Fraga More articles by this author Miguel Silva Ramos More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Comparison of safety and efficacy of laparoscopic pyelolithotomy versus percutaneous nephrolithotomy in patients with renal pelvic stones: a randomized clinical trial.

A randomized clinical trial was designed to compare the efficacy, success rate and surgical complications of percutaneous nephrolithotomy (PCNL) and laparoscopic pyelolithotomy (LP). Sixty patients with renal pelvic stones larger than 2 cm were randomly divided into two groups of LP and PCNL. All patients were followed up to three months after surgery using renal diethylenetriamine&shy;pentaaceticacid (DTPA) scan and determining the glomerular filtration rate (GFR). Mean operation time (149 &plusmn; 31 vs. 107 &plusmn; 26 min) and mean hospital stay (3.4 vs. 2.16 days) were significantly higher in LP, but mean hemoglobin drop (0.85 vs. 1.88 g/dL) and the rate of blood transfusion were significantly lower. Stone free rate was 90% and 86.6% for LP and PCNL, respectively (P =.59), while the changes in GFR were not statistically significant 3 days after surgery between two groups. Those in LP group showed better improvement in GFR at three months postoperatively. Improvement of the affected split kidney function was significantly higher in LP group (P =.04). No major complications were observed in both groups according to Clavien grading system. PCNL remains the gold standard treatment for most large kidney stones, nevertheless, laparoscopic pyelolithotomy can be considered for selected cases especially in whom maximal preservation of renal function is &nbsp;necessary.&nbsp;