Renal Scan Research Articles

Influence of Aortic Arch Morphology on Renal Perfusion in Patients with Coarctation of the Aorta: An Exploratory Study.

Objectives: The configuration of the aortic arch, particularly a Gothic arch shape, in individuals with corrected coarctation of the aorta (CoA) has been associated with a decreased systolic wave amplitude across the arch, which could potentially impair renal perfusion and elevate the risk of arterial hypertension. This study aims to explore the relationship between the morphological characteristics of the aortic arch and their impact on renal perfusion in patients with CoA. Methods: Seventy-one subjects with corrected CoA underwent continuous 24 h ambulatory blood pressure monitoring, computed tomography to assess the aortic arch, and renal perfusion scanning. Subjects were stratified into three groups based on the height-to-width (H/W) ratio of their aortic arch: Group 1 with a H/W ratio of <0.65, Group 2 with a H/W ratio between 0.65 and 0.85, and Group 3 with a H/W ratio of >0.85. Results: Groups 1 and 2 (53,78% and 62.63%) presented with a higher hypertension prevalence of elevated blood pressure than Group 3 (38.89%). Notable variations were observed among the subjects in the time to peak perfusion (Tmax) in the left kidney across the groups. Group 1 showed a median Tmax at 0.27, Group 2 at 0.13, and Group 3 at -0.38 (p-value = 0.079). The differences in Tmax for the right kidney followed a similar trend but were not statistically significant (Group 1 at 0.61, Group 2 at 0.22, and Group 3 at 0.11; p-value = 0.229). Conclusions: This study suggests that variations in the aortic arch morphology might not significantly influence renal perfusion in CoA patients. This indicates the potential adaptability of the renal blood flow, which appears to compensate for reduced perfusion, thus minimizing adverse effects on the kidney function. This adaptability suggests an inherent physiological resilience, emphasizing the need for further targeted research to understand the specific interactions and impacts on treatment strategies for CoA.

Deep-learning-based sampling position selection on color Doppler sonography images during renal artery ultrasound scanning

Accurate selection of sampling positions is critical in renal artery ultrasound examinations, and the potential of utilizing deep learning (DL) for assisting in this selection has not been previously evaluated. This study aimed to evaluate the effectiveness of DL object detection technology applied to color Doppler sonography (CDS) images in assisting sampling position selection. A total of 2004 patients who underwent renal artery ultrasound examinations were included in the study. CDS images from these patients were categorized into four groups based on the scanning position: abdominal aorta (AO), normal renal artery (NRA), renal artery stenosis (RAS), and intrarenal interlobular artery (IRA). Seven object detection models, including three two-stage models (Faster R-CNN, Cascade R-CNN, and Double Head R-CNN) and four one-stage models (RetinaNet, YOLOv3, FoveaBox, and Deformable DETR), were trained to predict the sampling position, and their predictive accuracies were compared. The Double Head R-CNN model exhibited significantly higher average accuracies on both parameter optimization and validation datasets (89.3 ± 0.6% and 88.5 ± 0.3%, respectively) compared to other methods. On clinical validation data, the predictive accuracies of the Double Head R-CNN model for all four types of images were significantly higher than those of the other methods. The DL object detection model shows promise in assisting inexperienced physicians in improving the accuracy of sampling position selection during renal artery ultrasound examinations.

Dynamic renal scans as a modality for follow-up of flexible ureteroscopy.

To determine whether dynamic renal scans - DTPA or MAG3 - routinely performed after flexible ureteroscopies (f-URS) could detect the development of an obstruction and thus promote prompt early intervention for kidney preservation. In this retrospective study, with all the data recorded prospectively between April 2010 and October 2023, 250 renal units in 242 patients with upper urinary tract stones (UUTS) who underwent ureterorenoscopy by one surgeon in the same medical center were evaluated. Stone-free rate (SFR) was defined as no residual fragments at all using an intraoperative "triple test". The following characteristics were examined: gender, BMI, age, Hounsfield unit, stone diameter, laterality, renal/ureteral stones, stone-free rate, and auxiliary procedures per renal unit. The Clavien-Dindo classification was used to report complications. Renal units with residual stones were scheduled for a 2nd f-URS. Post- flexible ureteroscopy ureteral obstruction and renal function were detected using renal scan DTPA or MAG-3. The primary outcome was renal/ ureteral obstruction. The mean patient age was 53 years. The mean stone size was 12.3 mm. Stones in renal pelvis, upper, middle and lower calyces were treated in 9.2% (23), 27.6% (69), and 30.8% (77) of cases, respectively; 44% (110) ureteral stones were also treated. The single- and second-session SFRs were 94.8% and 99.7%, respectively. A third auxiliary procedure was needed in one renal unit (0.4%). The mean number of procedures per renal unit was 1.06 (264/250). Ureteral double-J stents were inserted in 53.6% (134) of the cases. In 37 (14.8%) cases, a stent was placed before surgery. Post-operative complications were minor, with readmission and pain control needed in only two patients (0.8%). No avulsion or perforation of the ureters was observed. In six patients with t1/2 between 10-20 minutes, a second renal scan revealed spontaneous improvement and no obstruction in five patients. One patient with large stones and a history of prior ureteroscopy developed a ureteral stricture (0.4%) and needed treatment with laser endoureterotomy. Post-flexible ureteroscopy obstruction due to ureteral stricture is very rare. A routine renal scan post-operatively may be used in potentially high-risk patients.

Magnetic resonance imaging as a noninvasive adjunct to conventional assessment of functional differences between kidneys in vivo and during ex vivo normothermic machine perfusion

Normothermic machine perfusion (NMP) is increasingly considered for pretransplant kidney quality assessment. However, fundamental questions about differences between in vivo and ex vivo renal function, as well as the impact of ischemic injury on ex vivo physiology, remain unanswered. This study utilized magnetic resonance imaging (MRI), alongside conventional parameters to explore differences between in vivo and ex vivo renal function and the impact of warm ischemia on a kidney’s behavior ex vivo. Renal MRI scans and samples were obtained from living pigs (n = 30) in vivo. Next, kidney pairs were procured and exposed to minimal, or 75 minutes of warm ischemia, followed by 6 hours of hypothermic machine perfusion. Both kidneys simultaneously underwent 6-hour ex vivo perfusion in MRI-compatible NMP circuits to obtain multiparametric MRI data. Ischemically injured ex vivo kidneys showed a significantly altered regional blood flow distribution compared to in vivo and minimally damaged organs. Both ex vivo groups showed diffusion restriction relative to in vivo. Our findings underscore the differences between in vivo and ex vivo MRI-based renal characteristics. Therefore, when assessing organ viability during NMP, it should be considered to incorporate parameters beyond the conventional functional markers that are common in vivo.

The role of renal parenchyma to hydronephrosis area ratio in the evaluation of ureteropelvic junction obstruction in children

Purpose For the initial assessment and follow-up of patients with ureteropelvic junction obstruction (UPJO), we conducted this prospective study to assess the renal parenchyma to hydronephrosis area ratio (PHAR) in conjunction with the renal scan in patients who will undergo pyeloplasty. Patients and methods Patients who had visited the outpatient clinic for 2 years were diagnosed with UPJO, and fit the requirements for requiring surgical intervention were chosen. Before pyeloplasty and 3 months after surgery, PHAR and a renal isotope scan were conducted concurrently. Results Thirty-six patients were evaluated. After the operation, 31 (86.1%) cases improved and five (13.9%) cases did not improve. There was a significant change in all parameters at 3 months postoperatively as the mean T½ has significantly decreased (25.22±2.49 vs. 17.57±3.84). Also, there was a significant increase in the mean parenchymal thickness (9.42±4.92 vs. 15.12±4.86), glomerular filtration rate of the affected kidney (34.31±3.31 vs. 48.32±6.99) split renal function (37.30±3.80 vs. 44.03 ±4.11) and PHAR (0.86±0.30 vs. 2.45±0.93) at 3 months postoperative. PHAR postoperatively shows a positive correlation with parenchymal thickness, glomerular filtration rate of the affected kidney, and renal split function, while there is a negative correlation with T½. Conclusion PHAR is a potential noninvasive measure that may be evaluated during ultrasonography assessment to aid in predicting future surgical needs for UPJO and for postpyeloplasty follow-up in pediatric patients.

Limitations of Parenchymal Volume Analysis for Estimating Split Renal Function and New Baseline Glomerular Filtration Rate After Radical Nephrectomy.

Accurately predicting new baseline glomerular filtration rate (NBGFR) after radical nephrectomy (RN) can improve counseling about RN vs partial nephrectomy. Split renal function (SRF)-based models are optimal, and differential parenchymal volume analysis (PVA) is more accurate than nuclear renal scans (NRS) for this purpose. However, there are minimal data regarding the limitations of PVA. Our objective was to identify patient-/tumor-related factors associated with PVA inaccuracy. Five hundred and ninety-eight RN patients (2006-2021) with preoperative CT/MRI were retrospectively analyzed, with 235 also having NRS. Our SRF-based model to predict NBGFR was: 1.25 × (GlobalGFRPre-RN × SRFContralateral), where GFR indicates glomerular filtration rate, with SRF determined by PVA or NRS, and with 1.25 representing the median renal functional compensation in adults. Accuracy of predicted NBGFR within 15% of observed was evaluated in various patient/tumor cohorts using multivariable logistic regression analysis. PVA and NRS accuracy were 73%/52% overall, and 71%/52% in patients with both studies (n = 235, P < .001), respectively. PVA inaccuracy independently associated with pyelonephritis, hydronephrosis, renal vein thrombosis, and infiltrative features (all P < .03). Ipsilateral hydronephrosis and renal vein thrombosis associated with PVA underprediction, while contralateral hydronephrosis and increased age associated with PVA overprediction (all P < .01). NRS inaccuracy was more common and did not associate with any of these conditions. Even among cohorts where PVA inaccuracy was observed (22% of our patients), there was no significant difference in the accuracies of NRS- and PVA-based predictions. PVA was more accurate for predicting NBGFR after RN than NRS. Inaccuracy of PVA correlated with factors that distort the parenchymal volume/function relationship or alter renal functional compensation. NRS inaccuracy was more common and unpredictable, likely reflecting the inherent inaccuracy of NRS. Awareness of cohorts where PVA is less accurate can help guide clinical decision-making.

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.

Retroperitoneal lymphadenopathy: An underappreciated contributor to acute kidney failure in patients with cancer

Introduction: Retroperitoneal lymphadenopathy represents a unique and infrequent complication within various malignancies. This case report exemplifies the intricate diagnostic challenges that arise when identifying nondilated obstructive nephropathy in the context of retroperitoneal lymphadenopathy due to diffuse large B-cell lymphoma (DLBCL), particularly when conventional imaging fails to reveal the hallmark feature of hydronephrosis. Case description: We present a 66-year-old male with relapsed chronic lymphocytic leukemia post-allogeneic stem cell transplantation. His direct admission to the hematology/oncology service was due to failure to thrive. Despite the absence of hydronephrosis on imaging, the patient developed volume overload and increased serum creatinine levels. An ultrasound unveiled mild bilateral collecting system dilation, while laboratory findings did not provide valuable insight into the underlying etiology. A Lasix renal scan confirmed split renal function with minimal bilateral excretion. High clinical suspicion resulted in an MRI scan showing interval enlargement of retroperitoneal lymph nodes and pelvicaliectasis, which prompted urological and interventional radiology involvement. Conclusions: This case underscores the complexity of diagnosing retroperitoneal lymphadenopathy and pelvicaliectasis, in DLBCL, particularly when hydronephrosis is absent on imaging. It emphasizes the significance of clinical acumen, collaboration among specialties, and the use of advanced imaging techniques. Timely recognition of nondilated obstructive nephropathy in the setting of retroperitoneal lymphadenopathy is pivotal for guiding appropriate management strategies and optimizing patient outcomes in the intricate clinical setting.

Uretero-Pelvic Junction Obstruction with Calcification of Renal Pelvis Wall

A 45-year-old male presented with dull pain in right lumber region. On ultra-sonography, he had severely hydro- nephrotic right kidney with thinned out parenchyma and markedly dilated renal pelvis. On Computed Tomography, there was severe right hydronephrosis and linear calcification on the medial wall of renal pelvis confirmed further on DTPA Renal scan. It was a non-functioning kidney with a normal functioning contra-lateral kidney. The right nephrectomy was performed and a 7 x 7 cm rounded disc like calcification was seen in the medial pelvic wall. Upon histopathology, it was a dystrophic calcification of renal pelvis wall which is a rare finding.

Dose assessment of one- and five-year-old patients in renal SPECT scans with 99mTc-(DTPA, DMSA, MAG3, and EC)

Dose assessment of one- and five-year-old patients in renal SPECT scans with 99mTc-(DTPA, DMSA, MAG3, and EC)

The conundrum of high-grade hydronephrosis with non-obstructive drainage on diuretic renography

Patients with high grade hydronephrosis (HN) and non-obstructive drainage on mercaptoacetyltriglycine (MAG-3) diuretic renography (renal scans) can pose a dilemma for clinicians. Some patients may progress and require pyeloplasty; however, more clarity is needed on outcomes among these patients. Our primary objective was to predict which patients with high-grade HN and non-obstructive renal scan, (defined as T ½ time <20min) would experience resolution of HN. Our secondary objective was to determine predictors for surgical intervention. Patients with prenatally detected HN were prospectively enrolled from 7 centers from 2007 to 2022. Included patients had a renal scan with T ½<20min and Society for Fetal Urology (SFU) grade 3 or 4at last ultrasound (RBUS) prior to renal scan. Primary outcome was resolution of HN defined as SFU grade 1 and anterior posterior diameter of the renal pelvis (APD)<10mm on follow-up RBUS. Secondary outcome was pyeloplasty, comparing patients undergoing pyeloplasty with patients followed with serial imaging without resolution. Multivariable logistic regression was used for analysis. Of the total 2228 patients, 1311 had isolated HN, 338 patients had a renal scan and 129 met inclusion criteria. Median age at renal scan was 3.1 months, 77% were male and median follow-up was 35 months (IQR 20-49). We found that 22% (29/129) resolved, 42% of patients had pyeloplasty (54/129) and 36% had persistent HN that required follow-up (46/129). Univariate predictors of resolution were age≥3 months at time of renal scan (p=0.05), T ½ time≤5min (p=0.09), SFU grade 3 (p=0.0009), and APD<20mm (p=0.005). Upon multivariable analysis, SFU grade 3 (OR=4.14, 95% CI: 1.30-13.4, p=0.02) and APD<20mm (OR=6.62, 95% CI: 1.41-31.0, p=0.02) were significant predictors of resolution. In the analysis of decision for pyeloplasty, SFU grade 4 (OR=2.40, 95% CI: 1.01-5.71, p=0.04) and T ½ time on subsequent renal scan of ≥20min (OR=5.14, 95% CI: 1.54-17.1, p=0.008) were the significant predictors. Patients with high grade HN and reassuring renal scan can pose a significant challenge to clinical management. Our results help identify a specific candidate for observation with little risk for progression: the patient with SFU grade 3, APD under 20mm, T ½ of 5min or less who was 3 months or older at the time of renal scan. However, many patients may progress to surgery or do not fully resolve and require continued follow-up.

Is Percentage Improvement in Anteroposterior Pelvic Diameter a Valuable Marker for Successful Drainage Postpyeloplasty in Isolated Pediatric Pelvi-ureteric Junction Obstruction.

Pelvic-ureteric junction obstruction (PUJO) causes urine stasis in the renal pelvis and progressive kidney damage. Postpyeloplasty improvement of renal function and urinary drainage is assessed by diuretic isotope renogram and ultrasonography. Renograms are expensive and have radiation exposure. This study explores whether ultrasound parameters such as percentage improvement in anteroposterior pelvic diameter (PI-APD) is a valuable markers for successful pediatric pyeloplasties. The aim of this study was to identify patients who would benefit from ultrasound monitoring of PI-APD alone instead of diuretic isotope renal scan for postoperative follow-up of pyeloplasty. This was a retrospective descriptive study. We analyzed 127 pediatric pyeloplasties performed and under follow-up between June 2016 and May 2021. We recorded the postoperative ultrasound and isotope renogram parameters. PI-APD (preoperative AP diameter - postoperative AP diameter)/preoperative AP diameter × 100) was compared with improvement in renogram parameters (differential renal function, Tmax, curve pattern, and retention) to look for a correlation between them. SPSS version 20.5, Chi-square and paired t-test were used for statistical analysis. About 73.2% of patients were males, with most cases detected antenatally (76.4%). The majority was left-sided PUJO (67.7%). The mean age at surgery was 30.8 months. We identified a statistically significant correlation between the ultrasound parameter PI-APD and the renogram parameter Tmax. There is no significant correlation between PI-APD and other renogram parameters. In patients whose ultrasound parameter PI-APD is >40% and renal parenchymal thickness has increased, isotope renograms can be avoided for follow-up of postpyeloplasty patients.

99mTc-DMSA renal cortical scanning: a comparison of planar, SPECT, and SPECT/CT imaging for the detection of renal cortical scarring

BackgroundThe best way to assess renal cortical scarring is planar scintigraphy with 99mTc-dimercaptosuccinic acid (DMSA), while the value of single-photon emission computed tomography/computed tomography (SPECT/CT) is not well validated. The aim of the present study was to assess the value of planar, SPECT, and SPECT/CT scanning using 99mTc-DMSA in detecting renal cortical scarring.MethodsPatients with clinically suspected renal cortical scar were included in this prospective cohort. 99mTc-DMSA Planar images were obtained approximately 3–4 h after intravenous injection (IV) of 185 MBq of the tracer. SPECT/CT scans were obtained immediately after the planar ones. An expert nuclear medicine doctor who was unaware of the patient's clinical history or any previous imaging results analyzed the images. Each kidney was given a score of 0 for no obvious defects, 1 for equivocal lesions, 2 for a single defect, 3 for several defects, and 4 for non-visualized/non-functioning kidney (in CT images). The results of each method were then compared to each other.ResultsOne hundred eighty-six kidneys from ninety-three individuals were eligible for assessment. Planar scans detected 21 kidneys with equivocal lesions, 5 with single and 7 with multiple defects. SPECT scans detected 17 kidneys with single and 40 with multiple defects, while SPECT/CT scans revealed 5 with single and 11 with multiple defects. Only 5 of the 17 kidneys with single defects diagnosed by SPECT imaging had a scar in the SPECT/CT scans, whereas the remaining 12 had a solitary cortical cyst in the CT images. Only 11 of 40 kidneys with multiple defects on SPECT were shown to have a scar in the corresponding SPECT/CT images, whereas the rest matched to either hydro-nephrotic changes or multiple cortical cysts. Four kidneys with multiple defects on the SPECT/CT images were normal in the planar readings, were ascribed to an increase in renal background activity and a reduction in renal function.ConclusionsIn cases with suspected renal cortical scar, 99mTc-DMSA SPECT/CT scanning outperformed both planar and SPECT imaging by reducing the number of false-positive SPECT readings and false-negative planar readings.

Analysis of the Efficacy of Elastography in Comparison with Dynamic Renal Nuclear Scintigraphy in the Evaluation of Unilateral Pelvi–Ureteric Junction Obstruction

IntroductionIn hydronephrosis due to pelviureteric junction obstruction (PUJO), an obstruction to urine flow may lead to increased pelvic pressure, which may cause interstitial fibrosis and renal impairment. Recently, there have been reports on renal pelvic assessment using ultrasound elastography (USE). This study was conducted to see if USE can evaluate PUJO and if it can be correlated to the findings of the dynamic renal nuclear scan. Material and methodsIn this observational study, only patients with unilateral PUJO underwent acoustic radiation force impulse (ARFI) elastography. A rectangular region of interest (ROI) measuring 5 × 10 mm was positioned on the cortex region of the upper, mid, and lower poles of the affected kidney. Three valid measurements were obtained, from which a mean value was calculated. A dynamic renal nuclear scan using Technetium-99m ethylene dicysteine (EC or TC99 m EC) was obtained and split renal function (SRF) was used for comparison. ResultsIn the group of 20 patients, the mean age was 3.37 years. The mean SRF of the affected kidney was 26.65 %, and the corresponding USE value was 0.45 kpa. The Spearman's rho correlation coefficient for SRF and USE was 1 and 0.672, respectively (p = 0.001). Elastography was not feasible if SRF was less than 20 %. ConclusionUSE may be able to comment on the renal functional status of hydronephrosis. If USE is reported as non-feasible, it may suggest that renal function is grossly compromised. It may serve as an alternative diagnostic modality for renal functional evaluation. Level of evidenceLevel II, Prospective Cohort Study.

Evaluating Sonographers' Awareness of Artifacts in Renal Ultrasound Scans.

A routine ultrasound scan is used to assess a variety of renal pathological cases. Sonographers face a variety of challenges that may affect their interpretation. Understanding normal organ shapes, human anatomy, physical concepts, and artifacts is required for accurate diagnosis. Sonographers must understand how artifacts appear in ultrasound images in order to reduce errors and improve diagnosis. The purpose of this study is to assess sonographers' awareness and knowledge of artifacts in renal ultrasound scans. Participants in this cross-sectional study were asked to complete a survey containing different types of common artifacts in renal system ultrasound scans. An online questionnaire survey was used to collect the data. The questionnaire targeted radiologists, radiologic technologists, and intern students in Madinah hospitals in the ultrasound department. The total number of participants was 99, with 9.1% being radiologists, 31.3% being radiology technologists, 6.1% being senior specialists, and 53.5% being intern students. There was a significant difference in the participants' knowledge of ultrasound artifacts in the renal system with the total selection of the right artifact in senior specialists at 73% and intern students 45%. There was a direct relationship between age and years of experience in distinguishing artifacts in the renal system scan. A category of participants with the highest age and experience got 92% of the correct selection of artifacts. The study concluded that intern students and radiology technologists have limited knowledge of ultrasound scan artifacts, whereas senior specialists and radiologists have a high level of awareness of the artifacts.

Robotic-assisted laparoscopic pyeloplasty for ureteropelvic junction obstruction A retrospective review of a high-volume Canadian center.

At present, there is no literature on the outcomes of robotic-assisted laparoscopic pyeloplasty (RALPyelo) in a Canadian context. Our objective was to perform a retrospective review of RALPyelo cases at a high-volume Canadian center. We performed a retrospective review of patients who underwent RALPyelo at St. Michael's Hospital, between January 2012 and May 2019. Demographics, operative details, and pre- and postoperative imaging results (ultrasounds, computed tomography [CT] scans, and diuretic renal scan [DRS ]) were recorded. Patients were excluded if at least one-year followup data was unavailable. Our primary outcome was clinical and radiologic improvement defined as 1) symptom improvement; 2) stable/improved split renal function on DRS ; and 3) either improvement in the degree of hydronephrosis on ultrasound or CT, or improved drainage time on DRS. Secondary outcomes included postoperative complications, need for diagnostic intervention, and reintervention for recurrent UPJO. A total of 156 patients underwent RALPyelo after exclusions. The median age was 42 and 66% were female. Mean followup was 2.5 years. For our primary outcome, 87% had clinical and radiologic improvement. Diagnostic investigation for possible recurrent/persistent obstruction, based on symptoms and/or imaging results, was required in 17% of cases, but only 3% required reintervention for recurrent UPJO. Accordingly, the overall treatment success was 97%. The most common postoperative complication was urinary tract infection (18%), and urine leak was seen in only 2% of patients. The results of our study compare favorably with currently reported outcomes in the literature and demonstrate the safety and high level of success of RALPyelo at a high-volume Canadian center.

Renal Cortical Glucose Uptake Is Decreased in Insulin Resistance and Correlates Inversely With Serum Free-fatty Acids.

Studies on human renal metabolism are scanty. Nowadays, functional imaging allows the characterization of renal metabolism in a noninvasive manner. We have recently demonstrated that fluorodeoxyglucose F18 (18F FDG) positron emission tomography can be used to analyze renal glucose uptake (GU) rates, and that the renal cortex is an insulin-sensitive tissue. To confirm that renal GU is decreased in people with obesity and to test whether circulating metabolites are related to renal GU. Eighteen people with obesity and 18 nonobese controls were studied with [18F]FDG positron emission tomography during insulin clamp. Renal scans were obtained ∼60 minutes after [18F]FDG injection. Renal GU was measured using fractional uptake rate and after correcting for residual intratubular [18F]FDG. Circulating metabolites were measured using high-throughput proton nuclear magnetic resonance metabolomics. Cortical GU was higher in healthy nonobese controls compared with people with obesity (4.7 [3.4-5.6] vs 3.1 [2.2-4.3], P = .004, respectively), and it associated positively with the degree of insulin sensitivity (M value) (r = 0.42, P = .01). Moreover, cortical GU was inversely associated with circulating β-OH-butyrate (r = -0.58, P = .009), acetoacetate (r = -0.48, P = .008), citrate (r = -0.44, P = .01), and free fatty acids (r = -0.68, P < .0001), even when accounting for the M value. On the contrary, medullary GU was not associated with any clinical parameters. These data confirm differences in renal cortical GU between people with obesity and healthy nonobese controls. Moreover, the negative correlations between renal cortex GU and free fatty acids, ketone bodies, and citrate are suggestive of substrate competition in the renal cortex.

High Prognostic Value of 68Ga-PSMA PET/CT in Renal Cell Carcinoma and Association with PSMA Expression Assessed by Immunohistochemistry.

In oligo-metastatic renal cell carcinoma (RCC), neither computed tomography (CT) nor bone scan is sensitive enough to detect small tumor deposits hampering early treatment and potential cure. Prostate-specific membrane antigen (PSMA) is a transmembrane glycoprotein expressed in the neo-vasculature of numerous malignant neoplasms, including RCC, that can be targeted by positron emission tomography (PET) using PSMA-targeting radioligands. Our aim was to investigate whether PSMA-expression patterns of renal cancer in the primary tumor or metastatic lesions on immunohistochemistry (IHC) are associated with PET/CT findings using [68Ga]-PSMA-HBED-CC (PSMA-PET/CT). We then analyzed the predictive and prognostic role of the PSMA-PET/CT signal. In this retrospective single-center study we included patients with renal cancer submitted to PSMA-PET/CT for staging or restaging, with tumor specimens available for PSMA-IHC. Clinical information (age, tumor type, and grade) and IHC results from the primary tumor or metastases were collected. The intensity of PSMA expression at IHC was scored into four categories: 0: none; 1: weak; 2: moderate; 3: strong. PSMA expression was also graded according to the proportion of vessels involved (PSMA%) into four categories: 0: none; 1: 1-25%; 2: 25-50%; 3: >50%. The intensity of PSMA expression and PSMA% were combined in a three-grade score: 0-2 absent or mildly positive, 3-4 moderately positive, and 5-6 strongly positive. PSMA scores were used for correlation with PSMA-PET/CT results. Results: IHC and PET scans were available for the analysis in 26 patients (22 ccRCC, 2 papillary RCC, 1 chromophobe, 1 "not otherwise specified" RCC). PSMA-PET/CT was positive in 17 (65%) and negative in 9 patients (35%). The mean and median SUVmax in the target lesion were 34.1 and 24.9, respectively. Reporter agreement was very high for both distant metastasis location and local recurrence (kappa 1, 100%). PSMA-PET detected more lesions than conventional imaging and revealed unknown metastases in 4 patients. Bone involvement, extension, and lesion number were greater than in the CT scan (median lesion number on PET/CT 3.5). The IHC PSMA score was concordant in primary tumors and metastases. All positive PSMA-PET/CT results (15/22 ccRCC, 1 papillary cancer type II, and 1 chromofobe type) were revealed in tumors with strong or moderate PSMA combined scores (3-4 and 5-6). In ccRCC tissue samples, PSMA expression was strong to moderate in 20/22 cases. The SUVmax values correlated to the intensity of PSMA expression which were assessed using IHC (p = 0.01), especially in the ccRCC subgroup (p = 0.009). Median survival was significantly higher in patients with negative PSMA-PET/CT (48 months) compared to patients with a positive scan (24 months, p= 0.001). SUVmax ≥ 7.4 provides discrimination of patients with a poor prognosis. Results of PSMA-PET/CT changed treatment planning. Conclusions: in renal cancer, positive PSMA-PET/CT is strongly correlated to the intensity of PSMA expression on immunohistochemistry in both ccRCC and chromophobe cancer. PSMA-PET/CT signal predicts a poor prognosis confirming its potential as an aggressiveness biomarker and providing paramount additional information influencing patient management.

Risk factors for adverse outcomes after pediatric pyeloplasty: A retrospective cohort study.

To identify the risk factors for adverse outcomes after pediatric pyeloplasty. We conducted a retrospective review of all children under the age of 14 years who underwent primary pyeloplasty for unilateral ureteropelvic junction (UPJ) obstruction at a single teaching hospital in Tunisia between January 1, 2013, and December 31, 2022. A total of 103 patients were included. Median age of patients at surgery was 27 months (interquartile range [IQR], 13-44). On ultrasound, median renal pelvic anteroposterior diameter was 3.2 cm (IQR, 2.3-4), and the median renal cortex thickness (RCT) was 2.5 mm (IQR, 2-3.5). Median differential renal function (DRF) on preoperative radionuclide renal scan was 40% (IQR, 30-46). Postoperative adverse outcomes occurred in 28 patients (27.2%). These included 19 cases of urinary tract infections (UTIs), 11 cases of UPJ restenosis, four cases of UPJ leakage, two cases of urinoma, and two cases of diversion-related complications. Multivariate logistic regression analysis revealed two factors significantly and independently related to postoperative negative outcomes: RCT <3 mm and DRF > 50%. Our study demonstrated that preoperative RCT on ultrasound of less than 3 mm and preoperative DRF on radionuclide renal scan of more than 50% were independent risk factors for adverse outcomes following pediatric pyeloplasty. These factors could be of interest in identifying, early on, patients who will develop postoperative negative outcomes, giving them more attention and support, and explaining the prognosis to the patient and family.

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.