Technetium-99m Diethylenetriaminepentaacetic Acid Research Articles

The physiological basis of renal nuclear medicine.

Renal physiology underpins renal nuclear medicine, both academic and clinical. Clearance, an important concept in renal physiology, comprises tissue uptake rate of tracer (tissue clearance), disappearance rate from plasma (plasma clearance), appearance rate in urine (urinary clearance) and disappearance rate from tissue. In clinical research, steady-state plasma clearances of para-amino-hippurate and inulin have been widely used to measure renal blood flow (RBF) and glomerular filtration rate (GFR), respectively. Routinely, GFR is measured at non-steady state as plasma clearance of a filtration agent, such as technetium-99m diethylenetriaminepentaacetic acid. Scaled to three-dimensional whole body metrics rather than body surface area, GFR in women is higher than in men but declines faster with age. Age-related decline is predominantly from nephron loss. Tubular function determines parenchymal transit time, which is important in renography, and the route of uptake of technetium-99m dimercaptosuccinic acid, which is via filtration. Resistance to flow is defined according to the pressure-flow relationship but in renography, only transit time can be measured, which, being equal to urine flow divided by collecting system volume, introduces further uncertainty because the volume is also unmeasurable. Tubuloglomerular feedback governs RBF and GFR, is regulated by the macula densa, mediated by adenosine and renin, and can be manipulated with proximal tubular sodium-glucose cotransporter-2 inhibitors. Other determinants of renal haemodynamics include prostaglandins, nitric oxide and dopamine, while protein meal and amino acid infusion are used to measure renal functional reserve. In conclusion, for measuring renal responses to exogenous agents, steady-state para-amino-hippurate and inulin clearances should be replaced with rubidium-82 and gallium-68 EDTA for measuring RBF and GFR.

Impact of iodine contrast media on gamma camera-based GFR and factors affecting the difference between serum creatinine-based estimated GFR and Gate's GFR.

We aimed to elucidate the factors underlying the difference between estimated glomerular filtration rate (eGFR) calculated from serum creatinine and Gate's GFR (gGFR) measured using technetium-99m diethylene triamine pentaacetic acid ( 99m Tc-DTPA) scintigraphy. This study was based on consecutive patients who underwent 99m Tc-DTPA scintigraphy at our hospital between January 2021 and December 2022 and whose blood serum creatinine data were obtained on the same day as the 99m Tc-DTPA scintigraphy. Relationships between the ratio of gGFR and eGFR (gGFR/eGFR) and age, sex, BMI, visceral fat, psoas muscle index (PMI), serum blood urea nitrogen, and creatinine level were investigated based on 75 patients. Additionally, for 44 patients who had two or more follow-up DTPA studies, we compared gGFR values for studies that used iodine contrast media (ICM) for computed tomography before same-day 99m Tc-DTPA studies and those that did not in the same patients. Weak correlations were observed between gGFR/eGFR and PMI ( r = 0.30), BMI ( r = 0.24), and the visceral fat area ( r = 0.33). Multi-regression analyses showed that gGFR/eGFR was correlated with PMI ( β = 0.34, P < 0.01) and approached significance with the visceral fat area ( β = 0.24, P = 0.05). A significant difference was observed in gGFR between patients who received ICM before the 99m Tc-DTPA renogram and those who did not ( P < 0.001, eGFR 80.5 ± 19.0 vs. 91.7 ± 27.8 ml/min). ICM administration temporarily decreased gGFR, and increased muscle mass increased the difference between eGFR and gGFR values.

Correlation Diagnostic Contribution of SPECT/CT Imaging to 99mTc-DTPA Dynamic Scintigraphy in Patients with Different Renal Pathologies

Introduction: Dynamic renal scintigraphy with 99mTechnetium diethylenetriaminepentaacetic acid (99mTc-DTPA) is a widely performed imaging method to evaluate kidney function of patients with various renal pathologies. However the one-stop-shop combination with subsequent SPECT/CT imaging is a rarely discussed topic. Objective: The aim of the study was to evaluate the diagnostic benefits of SPECT/CT imaging to 99mTc-DTPA dynamic renal scintigraphy. Materials and Methods: A group of 32 patients (21 females and 11 males) who underwent dy- namic nephroscintigraphy with subsequent SPECT/CT was retrospectively studied. A dose of 185MBq (5mCi) 99mTc-DTPA was intravenously applied. A low-dose non-contrast CT protocol was used for attenuation correction and anatomical correlation. Results: Impaired relative renal function in various degrees of left kidney was detected in 18 patients (56%) and of right kidney in 14 patients (44%). SPECT/CT imaging identified the particular cause for the renal dysfunction in the analyzed subjects. The hybrid imaging demonstrated urolithiasis in 11 patients, postoperative ureteral strictures in 5 patients, diagnosed urological cancer in 4 patients and external compression of ureter in 2 patients as a possible obstructive cause. Congenital renal anomalies were the identified causes of impaired renal function in 10 patients – hypoplastic kidney in 4 patients, duplex kidney in 2 patients, multiple cortical cysts in 2 patients, aberrant vessel obstructing the pyeloureteral segment in 1 patient and horseshoe kidney in 1 patient. Conclusion: Dynamic renal scintigraphy combined with SPECT/CT is a very useful clinical tool, by providing not only functional but also anatomical information of the urinary tract, especially in the evaluation of obstructive uropathies and congenital renal abnormalities, that has the potential to change clinical management.

Performance of Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration Equations Versus 99Tc-DTPA-Renogram in Assessing Kidney Function.

To evaluate the performance of measurement of glomerular filtration rate (GFR) using Modification of Diet in Renal Disease equations (MDRD186, MDRD175) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, in comparison with technetium-99m diethylenetriaminepentaacetic acid (99Tc-DTPA) renogram method, the gold standard. A related aim was to correlate the three equations to estimate GFR and their impact on reclassifying the stages of CKD in adult Omani patients. This cross-sectional study recruited two groups of patients diagnosed with CKD during a 10-month period from January to October 2021. The first group comprised 48 patients who underwent a 99Tc-DTPA renogram procedure for GFR measurement, and the second group comprised 30 348 adult patients who did not undergo the same procedure; estimated GFR was calculated using the three equations. The median of the reference GFR was 106.0 mL/min/1.73 m2, whereas the median estimated GFR for the MDRD175, MDRD186, and CKD-EPI equations were 92.5, 98.3, and 102.1, respectively. All three equations correlated moderately with the reference GFR (0.428, 0.428, 0.523, respectively; p < 0.010). The CKD-EPI showed lesser bias (3.7 vs. 12.9 and 7.5 for MDRD175 and MDRD186, respectively) and more accuracy (95.8% vs. 91.7% and 93.8%); however, it was the least precise (25.1 vs. 22.3 and 23.8). The MDRD186 performed similarly to the CKD-EPI equation at CKD stages 3a-5 and differed significantly at stages 1-2. Whereas the MDRD175 differed significantly with both equations at stages 1-3b and was similar to them at stages 4-5. The CKD-EPI equation had the highest accuracy and the least bias and precision in the general population. The MDRD186 CKD classification differed significantly from the CKD-EPI equation at CKD-stages 1-2 only. The CKD-EPI equation is preferred to MDRD for the detection and classification of early CKD stages.

Glomerular filtration rate measurement during platinum treatment for urothelial carcinoma: optimal methods for clinical practice

BackgroundWe assessed the accuracy of four estimated glomerular filtration rate (eGFR) methods: MDRD, Cockcroft–Gault, CKD-EPI, and Wright.MethodThe four methods were compared to measure GFR (mGFR) in patients with urothelial urinary tract cancer (T2-T4bNxMx) receiving platinum-based chemotherapy at Rigshospitalet, Copenhagen, from January 2019 to December 2021. Using standardized assays, creatinine values were measured, and mGFR was determined using Technetium-99 m diethylenetriaminepentaacetic acid (Tc-99 m-DTPA) or Cr-51-ethylenediaminetetraacetic acid (Cr-51-EDTA) plasma clearance. Patients (n = 146) with both mGFR and corresponding creatinine values available were included (n = 345 measurements).ResultsThe CKD-EPI method consistently demonstrated superior accuracy, with the lowest Total Deviation Index of 21.8% at baseline and 22.9% for all measurements compared to Wright (23.4% /24.1%), MDRD (26.2%/25.5%), and Cockcroft–Gault (25.x%/25.1%). Bland Altman Limits of agreement (LOA) ranged from − 32 ml/min (Cockcroft–Gault) to + 33 ml/min (MDRD), with CKD-EPI showing the narrowest LOA (− 27 ml/min to + 24 ml/min and lowest bias (0.3 ml/min). Establishing an eGFR threshold at 85 ml/min—considering both the lower limit of agreement (LOA) and the minimum cisplatin limit at 60 ml/min—allows for the safe omission of mGFR in 30% of patients in this cohort.ConclusionCKD-EPI equation emerged as the most suitable for estimating kidney function in this patient group although not meeting benchmark criteria. We recommend its use for initial assessment and ongoing monitoring, and suggest mGFR for patients with a CKD-EPI estimated GFR below 85 ml/min. This approach could reduce costs and decrease laboratory time for 30% of our UC patients.

Evaluation of renal function with renography in patients with renal colic

Objective: Urolithiasis is responsible for the majority of urological emergencies. Although computed tomography (CT) scan can identify urinary obstruction caused by stones, there is a growing concern about exposure to radiation made by this method. Renal scintigraphy can provide valuable insights regarding the functional status of kidneys and can significantly reduce exposure to radiation.&#x0D; The goal of present study was to assess renal function through renal scintigraphy in patients with acute renal colic and it explores the association between renal scintigraphy performance and ultrasound in terms of detecting hydronephrosis.&#x0D; Methods: For this study, 20 patients with acute renal colic were chosen. Each patient underwent renal ultrasonography and subsequently received renal scintigraphy with Technetium-99m diethylenetriaminepentaacetic acid (Tc-99m DTPA). Cohen's Kappa coefficient and Cramer's V correlation were employed to demonstrate the extent of agreement between ultrasound and renal scintigraphy. &#x0D; Results: 12 (60%) patients were male. Glomerular filtration rate (GFR) values were correlated with Cockcroft-Gault equation and the Gates method (P=0.002, r=0.642). There was a good agreement and a statistically significant relationship between ultrasound and renal scintigraphy in terms of detecting obstructive uropathy in both kidneys.&#x0D; Conclusion: To conclude, GFR values were correlated between Cockcroft-Gault equation and the Gates method in patients with acute renal colic. There was a good agreement and statistically significant relationship between ultrasound and obstructive renography results in both kidneys. However, we found no association between perfusion phase of renal scintigraphy and ultrasonography in terms of hydronephrosis detection.

Clinical application of 99mTc-DTPA dynamic renal scintigraphy with consequent SPECT/CT imaging in patients with different nephrological conditions

Introduction: Dynamic renal scintigraphy with 99mTechnetium diethylenetriaminepentaacetic acid (99mTc DTPA) is a generally used imaging technique for evaluating renal function of patients with various nephro-urological conditions. Clinical application of SPECT/CT nephroscintigraphy has rarely been discussed. Objective: The aim of the study was to evaluate the added value of SPECT/CT imaging to dynamic renal scintigraphy with 99mTc DTPA. Materials and Methods: Thirty two patients (66% female and 34% male) who underwent dynamic nephroscintigraphy with subsequent SPECT/CT with mean age 55.9±18.25 years was observed. The CT scan was performed with a low dose protocol. A dose of 185MBq (5mCi) 99mTc DTPA was administered intravenously. Results: Our analysis demonstrated impaired relative renal function in various degrees of left kidney in 18 patients (56%) and of right kidney in 14 patients (44%). SPECT/CT imaging revealed the specific cause, responsible for the renal dysfunction in the cases. The hybrid imaging demonstrated urolithiasis in 11 patients, postopertative strictures of ureter in 5 patients, diagnosed urological cancer in 4 patients, external compression of ureter from ovarian cyst in 1 patient and compression of ureter due to nephroptosis in 1 patient as a possible obstructive cause. In 10 patients congenital renal anomalies were the identified causes of impaired renal function – hypoplastic kidney in 4 patients, duplex kidney in 2 patients, multiple cortical cysts in 2 patients, aberrant vessel obstructing the pyeloureteral segment in 1 patient and horseshoe kidney in 1 patient. Conclusion: The combination of conventional 99mTc DTPA dynamic renal scintigraphy with subsequent SPECT/CT could provide not only functional but also anatomical information of the urinary tract, especially in the evaluation of obstructive uropathies and congenital renal abnormalities, that can change the clinical management

Predicting estimated glomerular filtration rate after partial and radical nephrectomy based on split renal function measured by radionuclide: a large-scale retrospective study

PurposeThe purpose of this study was to develop predictive models for postoperative estimated glomerular filtration rate (eGFR) based on the split glomerular filtration rate measured by radionuclide (rGFR), as choosing radical nephrectomy (RN) or partial nephrectomy (PN) for complex renal masses requires accurate prediction of postoperative eGFR.MethodsPatients who underwent RN or PN for a single renal mass at Xijing Hospital between 2008 and 2022 were retrospectively included. Preoperative split rGFR was evaluated using technetium-99 m-diethylenetriaminepentaacetic acid (Tc-99 m DTPA) renal dynamic imaging, and the postoperative short-term (< 7 days) and long-term (3 months to 5 years) eGFRs were assessed. Linear mixed-effect models were used to predict eGFRs, with marginal R2 reflecting predictive ability.ResultsAfter excluding patients with missing follow-up eGFRs, the data of 2251 (RN: 1286, PN: 965) and 2447 (RN: 1417, PN: 1030) patients were respectively included in the long-term and short-term models. Two models were established to predict long-term eGFRs after RN (marginal R2 = 0.554) and PN (marginal R2 = 0.630), respectively. Two other models were established to predict short-term eGFRs after RN (marginal R2 = 0.692) and PN (marginal R2 = 0.656), respectively. In terms of long-term eGFRs, laparoscopic and robotic surgery were superior to open surgery in both PN and RN.ConclusionsWe developed novel tools for predicting short-term and long-term eGFRs after RN and PN based on split rGFR that can help in preoperative decision-making.

Voiding Sistoüretrogram ile Tanı Konulan Vezikoüreteral Reflü'nün Saptanmasında Dinamik Böbrek Sintigrafisinin Rolü

Aims: This study aims to evaluate the role of standardized dynamic renal scintigraphy (DRS) in recognizing vesicoureteral reflux (VUR) in patients detected with VUR by voiding cystourethrography (VCUG). Methods: The data of all pediatric patients who underwent both VCUG and DRS [technetium-99m diethylenetriamine pentaacetic acid (Tc-99m DTPA) or technetium-99m mercaptoacetyltriglycine dynamic renal scintigraphy (Tc-99m MAG-3)] in our hospital between 2013 and 2022 were retrospectively reviewed. Tc-99m MAG-3 was used in infants and Tc-99m DTPA radiopharmaceutical in children over one year old. According to VCUG findings, VUR grades were grouped as grade I-II-III low-grade VUR and IV-V high-grade VUR. The role of DRS in detecting VUR in both low and high-VUR-grade groups was evaluated. Results: A total of 56 patients (and 69 renal units), 23 girls (%41.1), and 33 boys (%68.9) were included in this study. The median value of the time elapsed between the DRS and VCUG examinations was nine days. According to VCUG, VUR was grade I in five renal units, grade II in 19 renal units, grade III in six renal units, grade IV in six renal units, and grade V in 33 renal units. DRS detected VUR in two of 30 renal units (%6.7) in the low VUR grade group. On the other hand, VUR was observed with DRS in 27 of 39 renal units (%69.2) in the high VUR grade group. Conclusions: Standardized DRS shows very low sensitivity in recognizing low-grade VUR, and its performance in detecting high-grade VUR is comparatively better. Raising awareness among clinicians that VUR can be observed with standardized DRS will benefit the patient in terms of early detection of accompanying VUR pathologies.

Measured Glomerular Filtration Rate in Live Related Kidney Donors Three Months Post-Kidney Donation: A Single-Center Experience From Western India.

Background Glomerular filtration rate (GFR) estimation is pivotal in the evaluation of kidney donors. There are various methods available for assessing GFR, but there has been a lack of consensus on the measurement of GFR and the frequency of renal evaluation after kidney donation. Our study aims to analyze the measured GFR (m-GFR) before and three months after kidney donation and note the compensatory abilities of the remnant kidney in live related kidney donors. Methods This prospective observational study was conducted at the Department of Nephrology, Dr. D. Y. Patil Medical College, Hospital & Research Centre,Pune, from April 2021 to December 2022. The study included 30 donors from both genders aged between 23 and 73 years. The measured GFR was calculated using a technetium-99m diethylene triamine pentaacetic acid (Tc-99m DTPA) scan. We analyzed donor characteristics and various parameters that included demography, anthropometry, blood pressure, and serum creatinine and measured GFR(m-GFR) using a Tc-99m DTPA scan, which was compared before and three months after donor nephrectomy. Results Of the 30 donors, 25 (83.3%) were females and five (16.7%) were males. The mean age of donors was 49.23 ± 12.29 years. The mean body mass index (BMI) was noted to be 24.73 ± 5.58 kg/m2, whereas themean body surface area (BSA) was1.59 ± 0.12 m2.In terms of the measured GFR by DTPA scan, pre-donationand post-donation, the average GFR for our population was 103.83 ± 10.07 mL/minute/1.73 m2 and60.47±6.57 mL/minute/1.73 m2, respectively.The mean measured GFR of remnant kidney increased by 9.21 ± 4.39 mL/minute/1.73 m2 in 28 donors, while two donors had a fall in the mean measured GFR by 6.8 ± 1.69 mL/minute/1.73 m2. Conclusions To safeguard donor health, accurate measurement of GFR at various timelines after kidney donation should be consideredas there are various limitations associated with the use ofserum creatinine-based GFR estimating equations for solitary kidneys. However, long-term studies are required to analyze the changes in GFR after nephrectomy and determine the adequacy of compensatory changes in the remnant kidney post-kidney donation.

Comparison of GFR measurement with a two-blood sample technique using [99mTc]Tc-DTPA vs. creatinine-based equations in potential kidney donors.

Accurate determination of glomerular filtration rate (GFR) is crucial for selection of kidney donors. Nuclear medicine methods are considered accurate in measuring GFR but are not always easily available. The four-variable Modification of Diet in Renal Disease (MDRD4), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and Full Age Spectrum (FAS) formulas are common equations for estimating GFR and are recommended for initial assessment of kidney donors. The aim of this study was to evaluate the performance of these GFR estimation equations compared with technetium-99m diethylenetriaminepentaacetic acid ([99mTc]Tc-DTPA) clearance. We compared GFR estimation by [99mTc]Tc-DTPA clearance using a two-blood sample method with estimation by MDRD4, CKD-EPI, and FAS creatinine-based equations in a population of healthy potential kidney donors. A total of 195 potential kidney donors (68.2% female; mean age 49 years, range 21-75 years) were included in this study. Mean [99mTc]Tc-DTPA measured GFR (mGFR) was 101.5 ± 19.1 mL/min/1.73 m2. All three equations underestimated the GFR value measured by [99mTc]Tc-DTPA (MDRD4: -11.5 ± 18.8 mL/min/1.73 m2; CKD-EPI: -5.0 ± 17.4 mL/min/1.73 m2; FAS: -8.3 ± 17.4 mL/min/1.73 m2). Accuracy within 30% and 10% of the measured GFR value was highest for CKD-EPI. The CKD-EPI equation showed better performance in estimating GFR in healthy potential kidney donors, proving to be a more accurate tool in the initial assessment of kidney donors. However, creatinine-based equations tended to underestimate kidney function. Therefore, GFR should be confirmed by another method in potential kidney donors.

A back propagation neural network approach to estimate the glomerular filtration rate in an older population

BackgroundThe use of creatinine-based glomerular filtration rate (GFR)-estimating equations to evaluate kidney function in elderly individuals does not appear to offer any performance advantages. We therefore aimed to develop an accurate GFR-estimating tool for this age group.MethodsAdults aged ≥ 65 years who underwent GFR measurement by technetium-99 m-diethylene triamine pentaacetic acid (99mTc-DTPA) renal dynamic imaging were included. Data were randomly split into a training set containing 80% of the participants and a test set containing the remaining 20% of the subjects. The Back propagation neural network (BPNN) approach was used to derive a novel GFR estimation tool; then we compared the performance of the BPNN tool with six creatinine-based equations (Chronic Kidney Disease-Epidemiology Collaboration [CKD-EPI], European Kidney Function Consortium [EKFC], Berlin Initiative Study-1 [BIS1], Lund-Malmö Revised [LMR], Asian modified CKD-EPI, and Modification of Diet in Renal Disease [MDRD]) in the test cohort. Three equation performance criteria were considered: bias (difference between measured GFR and estimated GFR), precision (interquartile range [IQR] of the median difference), and accuracy P30 (percentage of GFR estimates that are within 30% of measured GFR).ResultsThe study included 1,222 older adults. The mean age of both the training cohort (n = 978) and the test cohort (n = 244) was 72 ± 6 years, with 544 (55.6%) and 129 (52.9%) males, respectively. The median bias of BPNN was 2.06 ml/min/1.73 m2, which was smaller than that of LMR (4.59 ml/min/1.73 m2; p = 0.03), and higher than that of the Asian modified CKD-EPI (-1.43 ml/min/1.73 m2; p = 0.02). The median bias between BPNN and each of CKD-EPI (2.19 ml/min/1.73 m2; p = 0.31), EKFC (-1.41 ml/min/1.73 m2; p = 0.26), BIS1 (0.64 ml/min/1.73 m2; p = 0.99), and MDRD (1.11 ml/min/1.73 m2; p = 0.45) was not significant. However, the BPNN had the highest precision IQR (14.31 ml/min/1.73 m2) and the greatest accuracy P30 among all equations (78.28%). At measured GFR < 45 ml/min/1.73 m2, the BPNN has highest accuracy P30 (70.69%), and highest precision IQR (12.46 ml/min/1.73 m2). The biases of BPNN and BIS1 equations were similar (0.74 [-1.55−2.78] and 0.24 [-2.58−1.61], respectively), smaller than any other equation.ConclusionsThe novel BPNN tool is more accurate than the currently available creatinine-based GFR estimation equations in an older population and could be recommended for routine clinical use.

Comparison of Reliability of Kidney Ultrasound Findings After Pyeloplasty Versus Kidney Isotope Scans for Success in Patients with Ureteropelvic Junction Obstruction

Background: New parameters called the pelvis-cortex (P/C) ratio, and percentage of pelvic improvement (PI) in the anteroposterior diameter (APD) are used for patients with ureteropelvic junction obstruction who have undergone pyeloplasty. Early improvement in these ultrasonic parameters can prevent isotope scanning for a successful repair. Methods: The data of pediatric patients (age range: 0 - 14 years) who underwent open pyeloplasty in Mofid Children Hospital pediatric surgery ward from 2017 to 2021 with follow-up longer than 12 months were analyzed retrospectively. This study encompassed only those children whose ultrasound and Technetium-99m diethylene triamine pentaacetic acid (DTPA) renal information were available before and after surgery. Results: A total of 67 patients meeting inclusion criteria were registered. The mean age at operation was 30 ± 37.44 months. The mean pelvic APD before surgery was 33.93 mm. The mean kidney cortex diameter before surgery was 5.26 ± 2.07 mm. The mean P/C ratio before surgery was 7.56 ± 4.38. The mean preoperative split renal function was documented at 42.23%. The mean follow-up duration was 32 months. The mean APD 3 months after surgery was 18.1 mm. The mean kidney cortex diameter 3 months after surgery was 6.72 mm. The mean P/C ratio 3 months after surgery was 3.09. The PI in APD 3 months after surgery was 43.29%. The mean APD 6 months after surgery was 15.43 mm. The mean kidney cortex diameter 6 months after surgery was 7.24 mm. The mean P/C ratio 6 months after surgery was 2.8. The mean PI in APD 6 months after surgery was 50.83%. The mean postoperative tracer clearance half-time in diuretic renography was 20.77 minutes. In receiver operating characteristic curve analysis, it was observed that PI in APD &gt; 12% in 3 months after surgery versus DTPA 6 months after surgery could predict successful pyeloplasty with sensitivity, specificity, and area under the curve (AUC) equal to 98.44%, 66.67%, and 0.87, respectively. The PI in APD &gt; 26% 6 months after surgery versus DTPA 6 months after surgery could strongly predict successful pyeloplasty with sensitivity and specificity of 100% and AUC of 1. Conclusions: This study identified that PI in APD &gt; 26% at 6 months after surgery can strongly predict successful pyeloplasty and is a strong predictor of surgical outcome. Unnecessary repeated nuclear scans 6 months after surgery can be avoided using the aforementioned parameter.

Comparison of creatinine-based glomerular filtration rate estimation equations in voluntary Indian kidney donors: A single centre study

Introduction: In transplantation, accurate estimation of the donor glomerular filtration rate (GFR) is crucial. While various creatinine-based equations are in use, none are validated in Indians. Objectives: This study was conducted to judge the accuracy of creatinine-based GFR estimation equations and urinary creatinine clearance. Patients and Methods: A single-centre, observational and retrospective study at a tertiary care hospital. Adult voluntary donors GFR measured (mGFR) by technetium-99m diethylenetriaminepentaacetic acid (Tc-99m DTPA) were included. The primary outcome was the performance of estimated GFR (eGFR) by "Cockcroft-Gault’s formula corrected for body surface area (CG-BSA) formula", "modification of diet in renal disease (MDRD) 4 and 6 variable equation" and "Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation"; secondary outcome was the performance of "24-hour urinary creatinine clearance (Cr Cl)". Results: 102 kidney donors were analysed with mean age of 45.89 ± 9.98 years and 85.3% females. Mean ± SD mGFR by Tc-99m DTPA was 82.11 ± 14.32 mL/min/1.73 m2 . Mean ± SD eGFR by "CGBSA" was 99.68 ± 23.71 mL/min/1.73 m2 , by "MDRD-4 variable equation" was 98.25 ± 28.61 mL/ min/1.73 m2 , by "MDRD-6 variable equation" was 93.66 ± 19.44 ml/min/1.73 m2 and by "CKD-EPI" was 111.14 ± 31.61 mL/min/1.73 m2 . The lowest bias (2.3), highest precision (16.23), and accuracy (97.1%) were with "MDRD-6 variable equation"; "24-hour urinary Cr Cl" highly overestimated GFR (158.27 mL/min/1.73 m2 ) with the highest bias, lowest precision, and accuracy. Conclusion: The "MDRD-6 variable equation" was the most precise and accurate of the equations, whereas "24-hour urinary Cr Cl" was the least dependable. This study highlights the need for a correction factor or a new GFR estimation equation and not to consider urinary Cr Cl to assess donor GFR.

Clinical Comparison of the Glomerular Filtration Rate Calculated from Different Renal Depths and Formulae

A camera-based method using Technetium-99m diethylenetriaminepentaacetic acid (Tc-99m DTPA) is commonly used to calculate glomerular filtration rate (GFR), especially, as it can easily calculate split renal function. Renal depth is the main factor affecting the measurement of GFR accuracy. This study aimed to compare the difference of renal depths between three formulae and a CT scan, and, additionally, to calculate the GFRs by four methods. We retrospectively reviewed the medical records of patients receiving a renal dynamic scan. All patients underwent a laboratory test within one month, and a computed tomography (CT) scan within two months, before or after the renal dynamic scan. The GFRs were calculated by employing a renal dynamic scan using renal depth measured in three formulae (Tonnesen’s, Itoh K’s, and Taylor’s), and a CT scan. The renal depths measured by the above four methods were compared, and the GFRs were compared to the modified estimated GFR (eGFR). Fifty-one patients were enrolled in the study. The mean modified eGFR was 60.5 ± 42.7 mL/min. The mean GFRs calculated by three formulae and CT were 45.3 ± 23.3, 54.7 ± 27.5, 56.5 ± 26.3, and 63.7 ± 30.0, respectively. All of them correlated well with the modified eGFR (r = 0.87, 0.87, 0.87, and 0.84, respectively). The Bland–Altman plot revealed good consistency between the calculated GFR by Tonnesen’s and the modified eGFR. The renal depths measured using the three formulae were smaller than those measured using the CT scan, and the right renal depth was always larger than the left. In patients with modified eGFR &gt; 60 mL/min, the GFR calculated by CT was the closest to the modified eGFR. The Renal depth measured by CT scan is deeper than that using formula, and it influences the GFR calculated by Gate’s method. The GFR calculated by CT is more closely related to modified eGFR when modified eGFR &gt; 60 mL/min.

Radionuclide, magnetic resonance and computed tomography imaging in European round back slugs (Arionidae) and leopard slugs (Limacidae)

Other than in animal models of human disease, little functional imaging has been performed in most of the animal world. The aim of this study was to explore the functional anatomy of the European round back slug (Arionidae) and leopard slug (Limacidae) and to establish an imaging protocol for comparative species study. Radionuclide images with single photon emission computed tomography (SPECT) and positron emission tomography (PET) were obtained after injections of standard clinical radiopharmaceuticals 99mtechnetium dicarboxypropane diphosphonate (bone scintigraphy), 99mtechnetium mercaptoacetyltriglycine (kidney function), 99mtechnetium diethylenetriaminepentaacetic acid (kidney function), 99mtechnetium pertechnetate (mediated by the sodium-iodide symporter), 99mtechnetium sestamibi (cardiac scintigraphy) or 18F-fluoro-deoxyglucose (glucose metabolism) in combination with magnetic resonance imaging (MRI) and computed tomography (CT) for uptake anatomic definition. Images were compared with anatomic drawings for the Arionidae species. Additionally, organ uptake data was determined for a description of slug functional anatomy in comparison to human tracer biodistribution patterns identifying the heart, the open circulatory anatomy, calcified shell remnant, renal structure (nephridium), liver (digestive gland) and intestine. The results show the detailed functional anatomy of Arionidae and Limacidae, and describe an in vivo whole-body imaging procedure for invertebrate species.

MO190NORMATIVE DATA FOR GLOMERULAR FILTRATION RATE IN HEALTHY KIDNEY DONOR POPULATION

Abstract Background and Aims Glomerular filtration rate (GFR) is estimated traditionally from 24-hour urinary creatinine clearance. Creatinine is mainly filtered by glomerulus. The collection of 24-hour urinary sample is a difficult task with many patients fail to collect all the urine samples. As measuring GFR is cumbersome, expensive, and not easily available in all centers, various equations are developed for estimating GFR from creatinine like MDRD, CKD EPI creatinine. GFR obtained from serum creatinine shows wide variation as muscle mass and dietary protein intake are important determinants of serum creatinine concentration. Literature shows very few studies with GFR estimation with reference to age in Indian population. Hence, this study is planned to develop age specific nomogram for GFR in healthy kidney donor population as well as to study agreement between GFR obtained by 99m Tc DTPA three sample method and GFR estimated by 24-hour urinary creatinine. The aim of this stidy was to develop age-specific nomogram GFR in healthy kidney donor population and to study the agreement between the GFR measured by Technetium-99m diethylene triamine pentaacetic acid (99m Tc DTPA) and 24-hour urinary creatinine method. Method This study was conducted at Sir Ganga Ram hospital, New Delhi. All healthy individuals aged more than 20 years and less than 65 years, undergoing evaluation as prospective kidney donor at our hospital were the part of this study. GFR was measured by 99m Tc DTPA clearance using 3 sample method. GFR measured by DTPA method was used to develop nomogram. Creatinine Clearance was calculated from 24-hour urinary creatinine by formula U x V/P where, U is urinary creatinine level, P is plasma creatinine level and V is total volume of urine. Nomogram was developed with respect to these 3 Age groups; namely, 20 to 40 years, 40 to 50 years and 50 to 65 years Results Total 100 kidney donors were included in this study. Enrolled subjects were divided into 3 age groups; 20 to 40 years (n=28), 40 to 50 years (n=46) and 50 to 65 years (n=26). Majority of the donors were females (n=80). The agreement between GFR obtained by 99m Tc DTPA and 24-hour urinary creatinine clearance methods was 92.6 vs. 94 ml/min, 80.4 vs. 76 ml/min and 76.3 vs. 70 ml/min in respective age groups. Conclusion In the younger age group (20 to 40 years), there is better agreement in GFR measured by 99m Tc DTPA method and 24-hour urinary creatinine clearance methods.

Relative renal functions for children using &lt;sup&gt;99m&lt;/sup&gt;TC-DTPA and &lt;sup&gt;99m&lt;/sup&gt;TC-DMSA

Radionuclides are widely used to study the relative renal functions (RRFs) for kidney patients. This work reports the determination of the RRFs using the technetium-99m dimercaptosuccinic acid (99mTc-DMSA) and technetium-99m diethylenetriamine-pentaacetic acid (99mTc-DTPA) for children having kidney diseases. The two methods are then compared to find the choice of scintigraphy for a particular type of disease. A total of 65 child kidney patients of ages 5 months - 16 years were the representative samples of the study. The mean RRFs calculated with 99mTc-DTPA was found as and respectively, for the left and right kidneys. On the other hand, the values are and respectively, using 99mTc-DMSA. a significant positive correlation () were found between the RRFs calculated with the two scanning methods in Pearson correlation analysis. In one way ANOVA test, we did not find any difference between the RRFs calculated with 99mTc-DTPA and 99mTc-DMSA between the left and right kidneys. In Bland-Altman Plots, no mean difference was found between the two scanning methods and the correlation limit lies between -13.5 and12.6. The present study suggests using a single method for a particular type of disease. 99mTc-DMSA is the primary choice for the evaluation of RRF since it is easy, inexpensive and also provides cortical morphology, renal scar and cyst evaluation. But for glomerular filtration rate and renogram curve, 99mTc-DTPA should be the obvious selection as 99mTc-DMSA fails to provide any information for these cases.&#x0D; Journal of Bangladesh Academy of Sciences, Vol. 44, No. 2, 109-119, 2020

Urinary biomarkers as point-of-care tests for predicting progressive deterioration of kidney function in congenital anomalies of kidney and urinary tract: trefoil family factors (TFFs) as theemerging biomarkers.

Children with congenital anomalies of kidney and urinary tract (CAKUT) are at high risk of progressive deterioration of kidney function and further developing stage5 chronic kidney disease (CKD5), even after a successful surgery. This prospective study was designed to determine whether urinary biomarkers can predict progressive deterioration of kidney function in children with CAKUT. The study included 50 consecutive children, aged < 14 years, who were diagnosed with congenital uropathies (PUV, VUR, and PUJO) and 20 age-matched controls. Examination of four urinary biomarkers, i.e., trefoil family factors (TFF) 1 and 3, neutrophil gelatinase-associated lipocalin (NGAL) and microalbuminuria (MALB) was done at the beginning of follow-up. Kidney function was assessed, at the beginning and after 12-months of follow-up, by technetium-99m diethylene triamine pentaacetic acid (DTPA) and technetium-99m dimercaptosuccinic acid (DMSA) scans. Progressive deterioration in the kidney function was defined as a fall in the GFR from ≥ 60 to < 60 ml/min/1.73 m2 on comparing the baseline and latest DTPA scans; and/or new-onset cortical scar/scars or increase in the size of previous scar/scars on serial DMSA scans. Group 1 and group 2 included children without and with progressive functional deterioration respectively. The median (IQR) age of children with CAKUT and controls was 3 (1.5-5) and 2.3 (1.2-3.6) years, respectively, and showed no significant difference (p = 0.29). Median concentrations of TFF1, TFF3, NGAL, and microalbumin in patients were 44.5, 176.5, 281.2, and 15.5 mcg/gCr, respectively, and were significantly elevated as compared to controls (p < 0.05). Children belonging to group 2 had significantly higher concentration of biomarkers as compared to those in group 1. TFF3 was found have the highest AUC (0.9198) on ROC curve for predicting progressive functional deterioration. Urinary TFFs, NGAL, and microalbumin significantly correlate with progressive deterioration of kidney function in children harboring CAKUT. TFF3, with the strongest prediction of functional deterioration, is an emerging peptide showing sufficient potential to be included in the biomarker panel. Graphical abstract.

Establishment of normal reference ranges for total and separate glomerular filtration rates in living kidney donors by Gates' method after renal depth measured using single-photon emission computed tomography/computed tomography.

The underestimation of renal depth by Tønnesen formula in Gates' method, which has been confirmed by many scholars, leads to the underestimation of both separate glomerular filtration rate (gSGFR) and total glomerular filtration rate (gTGFR). This study aimed to establish the normal reference ranges of renal depth-calibrated gTGFR and gSGFR in Chinese healthy adults, and to analyze the influencing factors. Renal depth was measured by CT scan followed by technetium 99m-diethylene triamine pentaacetic acid (99mTc-DTPA) renal dynamic imaging by single-photon emission computed tomography/computed tomography (SPECT/CT) in 329 living kidney donors. The renal depth-calibrated gTGFR and gSGFR were calculated by Gates' method with renal depth measured by CT instead of being calculated by the Tønnesen formula. A general linear model based on age, gender, body height, body weight, and BMI was used to analyze factors influencing gSGFR (L), gSGFR (R) and gTGFR. The average gSGFR (L), gSGFR (R), and gTGFR for patients aged 23-64 years old were 49.3±10.1, 49.9±10.4, and 99.1±18.7 mL/min/1.73 m2, respectively. The gSGFR (L), gSGFR (R) and gTGFR for patients aged 41-50 years old were 26.9-69.3, 27.7-68.8, and 57.5-135.3 mL/min/1.73 m2, respectively, and those for patients aged 51-60 years old were 31.0-61.5, 29.5-63.3, and 64.6-120.7 mL/min/1.73 m2, respectively. gSGFR (L), gSGFR (R) and gTGFR had statistical significance with body height and age (P<0.05); however, there was no significant difference with gender, body weight, and BMI (P>0.05). For each 1 year increase in age, the gSGFR (L), gSGFR (R), and gTGFR decreased by 0.17, 0.28, and 0.44 mL/min/1.73 m2, respectively, while for every 1 cm increase in body height, the gSGFR (L), gSGFR (R), and gTGFR decreased by 0.37, 0.36, and 0.74 mL/min/1.73 m2, respectively. Normal reference ranges for renal depth-calibrated gSGFR (L), gSGFR (R), and gTGFR were established in healthy Chinese adults aged 23-64 years, and gSGFR (L), gSGFR (R), and gTGFR decreased with age and body height.