Renal Ultrasound Research Articles

Validity and Test-Retest Reliability of a Hand-Held Ultrasound Device in Measuring Kidney Metrics in Healthy Young Adults

Objective: The use of a hand-held ultrasound device provides a portable, cost-effective solution for renal assessments in rural settings, but their accuracy and reliability in measuring kidney metrics remain uncertain. The aim of this study was to evaluate the validity and reliability of the Lumify hand-held ultrasound device (LHUS) in capturing basic kidney metrics in healthy adults. Materials and Methods: Twenty individuals underwent renal sonography measurements, which included length, height, width, cortical thickness, parenchymal echogenicity, and renal resistive index (RRI). These measurements were completed using LHUS and the Epiq Elite ultrasound equipment system. LHUS measurements were repeated for test-retest reliability (TRR). Validity and TRR were assessed using intraclass correlation coefficient (ICC), Bland-Altman plots, coefficient of variation (COV), and mean absolute percent error (MAPE). Results: There was poor agreement (0.414, p = .048) between equipment systems for RRI. All other measures demonstrated moderate to excellent agreement (ICC = 0.75–0.94, p < .001) between systems. The left kidney showed poor agreement for RRI (0.06, p = .45). MAPE for all measurements between devices was <5%, indicating acceptable accuracy. All repeated measurements showed moderate to excellent reliability (ICC = 0.71–0.96, p < .001), with low mean COV for each measurement (0.02–0.08). Conclusion: Based on this study, LHUS appears to be a valid and reliable tool for basic kidney metrics in healthy adults, but caution should be used when obtaining an RRI, especially in the left kidney.

Ultrasonic renal length as an indicator of renal fibrosis severity in non-diabetic patients with chronic kidney disease.

Debate continues regarding the potential of the ultrasonic renal length to serve as an indicator for evaluating the advancement of renal fibrosis in chronic kidney disease (CKD). This study investigates the independent association between renal length and renal fibrosis in non-diabetic CKD patients and assesses its diagnostic performance. From April 2019 to December 2021, 144 non-diabetic patients diagnosed with CKD who underwent a renal ultrasound examination and kidney biopsy were prospectively enrolled. Patients were categorized into the mild fibrosis group (n = 70) and the moderate-severe group (n = 74) based on the extent of fibrotic involvement. Ultrasonic renal length was measured from pole-to-pole in the coronal plane. A receiver operating characteristic (ROC) curve, multivariable logistic regression analysis, and a generalized additive model were performed. A negative linear correlation was found between renal length and moderate-severe renal fibrosis risk. Each centimeter increase in renal length decreased the odds of moderate-severe fibrosis by 38% (OR: 0.62; 95% CI 0.41-0.93; P = 0.020). After adjusting for confounders, the relationship persisted (OR: 0.58; 95% CI 0.33-1.00; P = 0.048). However, renal length presented limited discrimination ability in distinguishing degrees of renal fibrosis while controlling the key confounding factors, yielding an area under the ROC curve of only 0.58 (95% CI 0.45-0.70). While an inverse relationship exists between renal length and risk of having moderate-severe renal fibrosis in non-diabetic CKD patients, renal length alone is insufficient for diagnosing fibrosis severity, underscoring the need for additional diagnostic parameters in CKD assessment.

Abstract 4130072: Prognostic Impact of Renal Microcirculatory Dysfunction in Heart Failure Assessed by the Advanced Doppler technique, Superb Microvascular Imaging

Aims: The significance of cardio-renal interactions in heart failure (HF) prognosis has become increasingly evident, yet there are no established methods to assess them. To address this issue, we propose a novel approach using Superb Microvascular Imaging (SMI), an ultrasound method that that enables detailed visualization of microvascular flow, to assess renal microcirculation. Methods: We retrospectively analyzed 78 patients who underwent renal ultrasonography using SMI from October 2020 to May 2023. We measured changes over time of Vascular Index (VI), which quantifies the blood flow signal area in the region of interest on the SMI image (Figure 1). Key measurements included Maximum VI (Max.VI), Minimum VI (Min.VI), and the cyclic variation of VI, calculated as the intrarenal perfusion index (IRPI) = (Max.VI - Min.VI) / Max.VI within one cardiac cycle. The primary endpoint of this study was a composite event (CE), defined as a composite of all-cause death and unplanned hospitalization for worsening HF. Results: During a mean follow-up period of 1.6±0.8 years, 13 of 78 patients (17%) experienced a CE. Compared with patients without CE, those with CE had significantly lower Max.VI (0.28±0.15 vs 0.46±0.18, p=0.002) and Min.VI (0.10±0.12 vs 0.22±0.14, p=0.007), and IRPI was significantly higher in the event group (0.68±0.19 vs 0.55±0.17, p=0.018). In univariable Cox regression analyses, Max.VI (HR 0.35, 95%CI 0.17-0.71, p=0.004), Min.VI (HR 0.28, 95%CI 0.10-0.75, p=0.012), IRPI (HR 1.97, 95%CI 1.11-3.51, p=0.021), creatinine (Cr) (HR 1.67, 95%CI 1.26-2.21, p<0.001) and estimated right atrial pressure by echocardiography (eRAP) (HR 4.22, 95%CI 1.42-12.5, p<0.001) were significantly associated with CE. In multivariable Cox regression analyses, Min.VI remained significantly associated with CE in the model adjusted for Cr (HR 0.35, 95%CI: 0.13-0.92, p=0.033), and in the model adjusted for eRAP (HR 0.11, 95%CI: 0.11-0.82, p=0.019). ROC curve analysis showed that, although not statistically significant, the predictive power of Min.VI was superior to that of Cr and eRAP (Figure 2). Stratifying patients by a Min.VI cut-off value of 0.08, determined through ROC analysis, showed that those with Min.VI < 0.08 had a significantly poorer prognosis (log-rank p<0.001) (Figure 3). Conclusion: The use of Superb Microvascular Imaging to assess renal circulation provides new insights into the prognosis of HF and allows risk stratification beyond conventional markers.

The ameliorative potential of platelet-rich plasma and exosome on renal ischemia/reperfusion-induced uremic encephalopathy in rats.

Uremic Encephalopathy results from the elevation of toxins and blood-brain barrier (BBB) disruption. Renal Ischemia/Reperfusion (I/R) injury is the principal cause of acute kidney injury and brain tissue injury. The present study was crafted to estimate the restorative impact of platelet-rich plasma (PRP) and exosome injection before the reperfusion phase on the kidney following renal I/R injury and its influence on brain tissue by tracking the histopathological, biochemical, and Doppler ultrasonography alternations in both kidney and brain tissue. Forty mature male rats were divided into five groups as follows: control, I/R, PRP, exosome, and Exosome + PRP. Renal Doppler ultrasonography was traced for all rats. Serum kidney functions and acetylcholine esterase enzyme (AchE) were evaluated. Both Gamma-aminobutyric acid (GABA) and glutamate were assessed in brain tissues. The oxidative stress (malondialdehyde), anti-oxidative (glutathione and catalase), and pro-inflammatory (Tumor necrosis factor- α and interleukin-6) markers were estimated in renal tissues. Additionally, morphometric histological examination was performed in both renal and brain tissues. Both PRP and exosome-received rats exhibited a significant improvement in both serum kidney functions and AchE compared to I/R rats. There was a 3.39-fold increase in GABA and a 2.27-fold decrease in glutamate levels in the brain tissue of PRP rats compared to the I/R rats. A significant elevation (P ≤ 0.0001) of glutathione and catalase besides a significant reduction in the expression of TNF-α and IL-6 was observed in renal tissue compared to I/R rats. A significant severe reduction (P < 0.0001) in the number of Purkinje cells, pyramidal cells in the cerebellar cortex, and the CA1 region in the hippocampus was observed in I/R rats which was significantly alleviated by both PRP and exosome. Furthermore, there was a significant improvement in Doppler parameters. PRP exerted a significant superior impact on the restoration of kidney functions and repairing uremic-induced damage in brain tissue.

Spontaneous Renal Arteriovenous Malformation Presenting with Hematuria: A Case Report

Introduction: Rare vascular abnormalities called renal arteriovenous malformations (AVMs) can cause hematuria among other symptoms. Due to overlapping clinical and radiological symptoms, differentiating between renal AVMs and other disorders such renal cell carcinoma (RCC) can be difficult. Here, we report a case of a patient who developed hematuria and was first diagnosed with renal AVM. We go over the difficulties in diagnosing this ailment and the approaches to managing it. Case Presentation: A 34-year-old female patient, reported having hematuria with clots for one week, coupled with fever and left loin discomfort that persisted for four and one day, respectively. Her hemoglobin level was 4.5 g/dL at arrival, which required packed red cell transfusions. A left double-J stent was implanted after an emergency cystoscopy revealed bloody efflux from the left ureteric orifice. A potential arteriovenous malformation in the left kidney's upper pole area was discovered by further imaging. A cirsoid-type AV abnormality arising from the superior polar branch of the renal artery was verified by renal angiography. After therapeutic embolization, the patient's symptoms were relieved and hematuria stopped. Discussion: The case study highlights the need of taking renal AVMs into account when making a differential diagnosis for hematuria, especially if there haven't been any previous urological operations. It also emphasises how important imaging techniques like renal angiography and renal ultrasonography with Doppler are for making the right diagnosis. Distinctive diagnosis from other ailments, such as renal cell carcinoma, highlights the necessity of comprehensive assessment and monitoring to guarantee suitable treatment. Conclusion: Renal arteriovenous malformations are rare but important causes of hematuria. Prompt diagnosis and management are crucial to prevent complications and improve patient outcomes. This case report demonstrates the diagnostic challenges associated with renal AVMs and underscores the importance of a multidisciplinary approach in their evaluation and treatment.

Residual congestion in acute decompensated heart failure: A novel approach through microvascular imaging of renal circulation

Abstract Background In patients admitted for acute decompensated heart failure (ADHF), residual congestion at discharge is associated with adverse clinical outcomes. Traditionally, the extent of congestion has been inferred from central venous pressure, but it has also been highlighted that this is insufficient for a comprehensive evaluation of residual congestion. On the other hand, renal congestion is an important finding of organ congestion, and Superb Microvascular Imaging (SMI), a technique that reveals minute flow details, is promising for assessing renal circulation. We hypothesized that in patients with ADHF, assessment of renal circulation using SMI may be superior to conventional methods in assessing residual congestion. Methods In this prospective study, we enrolled 45 consecutive patients admitted with ADHF. We performed comprehensive evaluations including blood tests, echocardiography, and renal ultrasonography using SMI. The vascular index (VI), as measured by SMI, was calculated as the percentage of blood flow signal area in the region of interest. Subsequently, we calculated the intra-renal perfusion index (IRPI), representing cyclic variation in VI, as (maximum VI - minimum VI) within one cardiac cycle, divided by the maximum VI (Figure). Brain Natriuretic Peptide (BNP) levels were utilized to evaluate the state of decongestion. Results At discharge, the mean IRPI was 0.61±0.04, while the median BNP levels were 204.9 pg/ml (interquartile range: 102.7, 428.2). Patients exhibiting elevated log BNP levels at discharge (&amp;gt;2.31, based on median value) displayed significantly higher IRPI values [0.61(0.49, 0.86) vs 0.53(0.35, 0.59), p=0.02] and were older (80.8±8.5 vs 70.3±14.9 years, p=0.010). However, no significant differences were observed regarding laboratory parameters including hematocrit and creatinine levels, as well as echocardiographic parameters such as ejection fraction, E/e' ratio, and estimated right atrial pressure (RAP). Moreover, at discharge, creatinine levels (p=0.56) and estimated RAP (p=0.06) exhibited no significant correlation with IRPI. Conclusion Renal circulation evaluated by SMI may serve as a useful indicator of the extent of residual congestion at discharge compared to blood tests and echocardiographic estimates of right atrial pressure in patients admitted for ADHF.

Renal medullary perfusion differs from that in renal cortex in patients with sepsis associated acute kidney injury and correlates with renal function prognosis: A prospective cohort study.

Renal perfusion status remains poorly studied at the bedside during sepsis associated acute kidney injury (AKI). The aim of the study is to examine renal cortical and medullary perfusion using renal contrast enhanced ultrasound (CEUS) in septic patients. In this single-center, prospective longitudinal study, septic patients were enrolled. Renal ultrasonography was performed within 24 hours of ICU admission (D1), then repeated at D3, D5 and D7. Each measurement consisted of three destruction replenishment sequences that were recorded for delayed analysis with dedicated software (Vuebox). Renal cortex and medulla perfusion were quantified by measuring time to peak (TTP). Receiver operating characteristic (ROC) analysis was used to evaluate 28-day renal prognosis. The study included 149 septic patients, including 70 non-AKI patients and 79 AKI patients. Both renal cortical and medullary TTP was longer in the AKI group than in the non-AKI group. The difference of TTP between renal cortex and medulla in AKI group was higher than that in the non-AKI group (p = 0.000). Medullary TTP on day 3 had the best performance in predicting the prognosis of 28-day renal function (AUC 0.673, 95% confidence interval 0.528-0.818, p = 0.024), and its cut-off value was 45 s with a sensitivity 52.2% and a specificity of 82.1%. Cortical TTP on day 3 also had the performance in predicting the prognosis of 28-day renal function (AUC 0.657, 95% confidence interval 0.514-0.800, p = 0.039), and its cut-off value was 33 s with a sensitivity 78.3% and a specificity of 55.0%. Renal medullary perfusion alterations differ from those in cortex, with the medulla is worse. Simultaneous and dynamic assessment of cortical and medullary microcirculatory flow alterations necessary. TTP on day 3, especially medullary TTP, seems to be a relatively stable and useful indicator, which correlates with 28-day renal function prognosis in septic patients. Early correction of renal cortical and medullary perfusion alterations reduces the incidence of adverse renal events.

A comparative study of postadrenalectomy hyperuricemia and renal impairment in patients with unilateral primary aldosteronism: does histopathology subtype matter?

BackgroundPrimary aldosteronism (PA), which is present in 5–18% of hypertensive patients, is a leading cause of secondary hypertension. Adrenalectomy is often recommended for patients with unilateral primary aldosteronism (uPA), yielding good long-term outcomes. PA patients without hyperuricemia and chronic renal failure before adrenalectomy were enrolled in this cohort study. Serum uric acid (SUA) and renal filtration were measured one year post-adrenalectomy. Their relationships with pathologic features, histopathological subtype (classical or nonclassical (HISTALDO consensus)), and vessel stiffness were explored. The aim of this cohort study is to evaluate the correlation between post-adrenalectomy serum uric acid (SUA) levels and estimated glomerular filtration rate (eGFR) with the pathologic features delineated by the HISTALDO consensus. Additionally, the study seeks to assess the impact of these biochemical markers on peripheral vessel stiffness and brachial-ankle pulse wave velocity (baPWV) at a one-year follow-up visit.MethodsThis prospective cohort study included patients (N = 100) diagnosed with uPA who underwent adrenalectomy from Jan 1, 2007 to Dec 31, 2022.ResultsAt follow-up, elevated SUA, hyperuricemia, and a > 25% eGFR decrease were significantly more common in the classical than the nonclassical group. The incidence of postoperative hyperuricemia, herein referred to as post-adrenalectomy hyperuricemia (PAHU), was 29% (29/100) overall, 34.8% (23/66) in the classical group and 17.6% (6/34) in the nonclassical group. The incidence of eGFR reduction > 25% was 33% (33/100), 43.9% (29/66), and 11.8% (4/34), respectively. baPWV decreased more in the classical group than the nonclassical group.ConclusionFor PA patients with PAHU and/or renal impairment, we suggest monitoring SUA, pH, urine uric acid, and urine crystals and performing a KUB study and peripheral vascular and renal sonography (on which pure uric acid stones in the KUB are radiolucent) to determine whether drug intervention is required for cases of asymptomatic PAHU, especially patients in male gender, classical histopathology, or renal impairment.

Renal Ultrasonography in Children: Principles and Emerging Techniques

Renal Ultrasonography in Children: Principles and Emerging Techniques

Chronic kidney disease associated with extremely premature birth and extremely low birth weight may progress through the burden of growth.

Chronic kidney disease associated with low birth weight and/or premature birth (L/P-CKD) in infants may result from a decreased number of nephrons at birth. These infants may develop acute kidney injury due to exposure to nephrotoxic substances or other events during nephrogenesis in early infancy. Nonetheless, L/P-CKD progression remains unclear. We present three cases of L/P-CKD diagnosed after neonatal intensive care unit (NICU) discharge. Three patients were born extremely prematurely (gestational age, 24-26weeks) with extremely low birth weight (606-906g). They were admitted to the NICU (117-311days) anad received several nephrotoxic medications during the early postnatal period. They showed elevated serum creatinine levels at 4weeks after birth, which decreased to normal levels at NICU discharge. Proteinuria was first detected during adolescence (10-15years) on annual school urine screening, with a remarkable increase in their height (18 - 50.8cm), without known episodes of urinary tract infection, dehydration, lifestyle-related issues, such as excessive salt/protein intake, and extreme lack of exercise that might have caused kidney damage. Their kidneys were smaller than normal on renal ultrasonography. Open renal biopsy findings indicated glomerulomegaly and perihilar glomerulosclerosis in two of the three patients, suggesting glomerular hypertension. The remarkable differences between the body height before CKD and the timing of diagnosis of CKD could contribute to the progress of CKD. Long-term follow-up of low birth weight and extremely premature infants, from NICU discharge until adulthood, should be established.

Transvesicoscopic Cohen Ureteric Reimplantation for Vesicoureteral Reflux in Children: A Pilot Study

Abstract Background Cohen’s pneumovesicoscopic reimplantation technique (CPRT) is a minimally invasive procedure that resembles the surgical steps of the open cross-trigonal reimplantation technique with a similar success rate and the inherent benefits of a minimally invasive approach, like less need for analgesia and less morbidity. Aim of the Work to evaluate the efficacy and safety of CPRT in 20 pediatric patients with primary VUR presented to 2 pediatric surgery departments, in 2 tertiary centers. Patients and Methods a prospective interventional study on 20 children (13 girls, 7 boys, age ranged from 4 to 12 years) with primary vesicoureteral reflux (VUR), grades II-IV (6 bilateral, 9 RT and 5 LT) underwent a CPRT. Suprapubic ports were placed: a 5-mm camera port and two 3- mm working ports. After the ureter(s) have been dissected transvesically a submucosal tunnel is made for ureteric reimplantation to be carried out using 5/0 absorbable sutures. After the procedure, the urethral catheter was taken out two days later, and the patients were released on day three. Clinical evaluation, renal ultrasonography, and voiding cystourethrogram were used to Follow-up the patients. Results 198.5 min was the average operating time (range 90 – 240 min). Two cases developed postoperative complications (mild suprapubic emphysema-perivesical hematoma) managed conservatively. One case needed conversion to open technique because of intraoperative complications (port displacement- perivesical air leakage). All patients had renal US and VCUG between 3 and 6 months after surgery. All low-grade reflux patients (grade II &amp; III) had their hydronephrosis disappear on postoperative US (13 out of 26 refluxing units), while persistence of grade I VUR on VCUG was in two cases (2 units). Conclusion Technically feasible, Cohen’s pneumovesicoscopic reimplantation technique can be carried out safely and effectively in children. It is advisable to select the patients carefully in the primary phase of this technique. Some technical modifications are suggested to overcome the technical obstacles faced, helping us to master this promising technique.

Prevalence of urinary metabolic disorders and risk factors of kidney stones in Iranian children

Introduction: Nephrolithiasis and urolithiasis, characterized by the formation of calculi in the kidney and lower urinary tract, respectively, pose a significant health concern for millions of children worldwide, particularly in developing countries. Objectives: This research aims to explore the prevalence of abnormal concentrations of urinary solutes as potential risk factors for kidney stones in Iranian children under the age of 14 years. Patients and Methods: A cross-sectional investigation spanning from January 2021 to January 2022 targeted children diagnosed with nephrolithiasis or urolithiasis through renal sonography, who were subsequently referred to the nephrology outpatient department of our hospital or our private pediatric nephrology office. Laboratory assessments encompassed urine calcium, oxalate, citrate, uric acid, creatinine, and urine cystine. Demographic attributes, stone composition (when available), and urinary metabolic disorders were scrutinized. Data analysis involved SPSS version 24, utilizing descriptive statistics such as mean, standard deviation, and frequency, categorized by variable type. Chi-square tests were employed for statistical analysis, with a significance threshold set at P&lt;0.05. Results: The study encompassed 486 children, with a mean age of 55.58 months and a male majority of 50.8%. Among those with kidney stones, 77.2% exhibited unilateral stones, while 22.8% presented with bilateral stones. Predominant urinary metabolic disorders included hypercalciuria (30.2%), hyperuricosuria (22.6%), and hyperoxaluria (20.6%). Notably, 25.7% of the children manifested a combination of multiple metabolic disorders. Significant variations in the prevalence of hyperuricosuria were observed across different age groups. Boys exhibited higher incidences of hypercalcemia and metabolic abnormalities compared to girls, though no statistically significant differences were noted in other disorders. Conclusion: In summary, our findings indicate the presence of abnormal urinary metabolic risk factors in over half of children diagnosed with kidney stones. Hypercalciuria was the more frequent risk factor following hyperuricosuria and hyperoxaluria, cystinuria with prevalence of 30.2%, 22.6%, 20.6%, and (2.1%) respectively.

Outcomes of Management of Anterior Anus in Girls in Glasgow, UK

BackgroundAnterior anus is considered part of the spectrum of anorectal malformations in girls and has been associated with childhood constipation. However, limited literature exists on outcomes and associated malformations. MethodsAll girls <6 months referred to our centre with suspected anterior anus between January 2015 and December 2022 were identified. Data collected included patient demographics, presence of anomalies, operative management, laxative use and continence. Results are described using descriptive statistics and percentages. Results147 girls were referred with suspected anterior anus of which 95 were confirmed to have an anterior anus. Median age of first assessment was 3 (0–13) months. Median follow up was 24 (1–94) months. 21 (22.1 %) had clinical concern of partial absence of normal circumferential anal corrugation. 10 (10.5%) girls underwent examination under anaesthesia; 4 patients underwent anoplasty with covering colostomy. Laxatives were prescribed in 31 (32.6%) girls. Of the 53 patients followed up to age 4 years and older, 51 (96.2%) achieved continence. On renal ultrasonography significant hydroureteronephrosis was detected in one patient. No significant spinal anomalies were detected on imaging. Two patients had ventricular-septal defects were identified. All significant anomalies were in patients with an ectopic anus/ perineal fistula. ConclusionThis represents the largest reported series of girls with anterior anus. The incidence of identified associated malformations was low. Furthermore, laxative use and continence outcomes are similar to the general infant/childhood population. Screening and routine follow-up should be reserved for individual cases where there is clinical concern.

NEONATAL ADRENAL HEMORRHAGE

Introduction: Adrenal hemorrhage is a rare condition in the neonatal period. The significant size of the adrenal gland and its particular hypervascularization are predisposing factors for bleeding, especially in cases of trauma or vascular thrombosis (of the renal vessels or the inferior vena cava). The aim of this study is to analyze the medical records to perform a descriptive study of neonates hospitalized in the Neonatology and Neonatal Resuscitation Department of CHU Hassan II in Fez. Method:The cross-sectional study included all cases of neonates diagnosed with adrenal hemorrhage based on renal ultrasounds performed at the Neonatology and Neonatal Resuscitation Department of CHU Hassan II in Fez, between January 2016 and December 2023. Result: Sixteen cases of adrenal hemorrhage were identified. The incidence of adrenal hemorrhage during the study period within the department was 2 per 1,000 hospitalizations. Both sexes are equally affected, with a male predominance of 62.5%. The two main reasons for hospitalization in our series were perinatal asphyxia and jaundice. Uterine expression was reported in 87.5% of cases. The most common clinical signs, in order of frequency, are: jaundice (56.25%), abdominal mass (50%), skin and mucous membrane pallor (31.25%), fever (31.25%), respiratory distress (31.25%), and fractures in 6.25% of cases. Severe hyperbilirubinemia was found in 3 patients, accounting for 18.75%. Anemia was found in 6 patients, or 37.5%. Adrenal insufficiency was observed in 3 cases, or 18.75%. Abdominal ultrasound was performed on all patients, revealing right adrenal hemorrhage in 8 cases, left in 5 cases, and bilateral in 3 cases. The outcome was favorable in 81.25% of cases, while 18.75% of patients died. Conclusion: Adrenal hematoma is a rare condition in the neonatal period but can be severe, which justifies systematically searching for it in the presence of risk factors. Abdominal ultrasound is the key diagnostic test. The condition typically resolves spontaneously after several weeks.

An innocent bystander or a predisposing culprit? Kidney injury following pediatric liver transplantation.

Survival after pediatric liver transplantation has increased dramatically over the years, revealing extra-hepatic complications including impaired kidney function. We conducted a large single-center retrospective study to evaluate kidney outcomes after pediatric liver transplantation. From electronic charts of 121 children who underwent liver transplantation during 2007-2020, we collected pre- and post-transplant data. We investigated the presence of post-transplant permanent kidney injury, including proteinuria, hypertension, and decreased estimated glomerular filtration rate (eGFR). We excluded children who died, underwent liver-kidney transplantation, or had less than 1year of follow-up. During a median follow-up of 5.1 (interquartile range 2.9-7.3) years, eGFR decreased, mostly in the first year post-transplant. In addition, 41% of the children presented with acute kidney injury. At their last follow-up, 35% showed permanent kidney injury (hypertension 13%, proteinuria 36%, and eGFR < 90mL/min per 1.73m2 7%). Kidney ultrasounds were abnormal for 44% of the children at the last visit, compared to 11% before transplant (p < 0.001). In multivariate analysis, abnormal kidney ultrasound before transplant (odds ratio = 4.53, 95% CI 1.1-18.7) and liver disease with potential risk of primary kidney involvement (odds ratio = 4.77, 95% CI 1.58-14.4) were predictors for hypertension or decreased eGFR at the last follow-up. The high prevalence of kidney injury after pediatric liver transplantation and the pretransplant predictors for kidney injury highlight the importance of a thorough kidney pretransplant evaluation and follow-up.

Cross-modal Transfer Learning Based on an Improved CycleGAN Model for Accurate Kidney Segmentation in Ultrasound Images

ObjectiveDeep-learning algorithms have been widely applied in the field of automatic kidney ultrasound (US) image segmentation. However, obtaining a large number of accurate kidney labels clinically is very difficult and time-consuming. To solve this problem, we have proposed an efficient cross-modal transfer learning method to improve the performance of the segmentation network on a limited labeled kidney US dataset. MethodsWe aim to implement an improved image-to-image translation network called Seg-CycleGAN to generate accurate annotated kidney US data from labeled abdomen computed tomography images. The Seg-CycleGAN framework primarily consists of two structures: (i) a standard CycleGAN network to visually simulate kidney US from a publicly available labeled abdomen computed tomography dataset; (ii) and a segmentation network to ensure accurate kidney anatomical structures in US images. Based on the large number of simulated kidney US images and small number of real annotated kidney US images, we then aimed to employ a fine-tuning strategy to obtain better segmentation results. ResultsTo validate the effectiveness of the proposed method, we tested this method on both normal and abnormal kidney US images. The experimental results showed that the proposed method achieved a segmentation accuracy of 0.8548 in dice similarity coefficient on all testing datasets and 0.7622 on the abnormal testing dataset. ConclusionsCompared with existing data augmentation and transfer learning methods, the proposed method improved the accuracy and generalization of the kidney US image segmentation network on a limited number of training datasets. It therefore has the potential to significantly reduce annotation costs in clinical settings.

Value of Urine Neutrophil Gelatinase Associated Lipocalin for Prediction of Ureteropelvic Junction Obstruction in Children

Background: Congenital obstructive nephropathy is a significant cause of chronic kidney damage in childhood. Therefore, early diagnosis and management of urinary tract obstruction are necessary to prevent or reduce further renal damage. Various biomarkers have been investigated for the early identification of urinary tract obstruction. Objectives: The aim of this study was to evaluate the excretion of urine neutrophil gelatinase-associated lipocalin (Urine neutrophil gelatinase-associated lipocalin (uNGAL) &amp; uNGAL/Cr) as a useful, sensitive, and non-invasive diagnostic biomarker in children with ureteropelvic junction obstruction (UPJO). Methods: The study cohort consisted of 47 children with obstructive UPJO and 47 healthy children with normal renal ultrasounds. Ultrasonography and 99mTc DTPA radionuclide scans were used for diagnosing UPJO. All affected children had normal renal function based on GFR measurements. Urine neutrophil gelatinase-associated lipocalin was measured using Immunoenzymatic ELISA commercial kits. Results: Urine neutrophil gelatinase-associated lipocalin &amp; uNGAL/Cr levels were significantly higher in children with obstructive UPJO compared to the healthy control group. Additionally, both biomarkers demonstrated acceptable sensitivity and specificity for predicting for predicting UPJO. Conclusions: Based on these results, measuring uNGAL &amp; uNGAL/Cr is suggested for evaluating children with obstructive UPJO.

Nephrocalcinosis and kidney function in children and adults with X-linked hypophosphatemia: baseline results from a large longitudinal study.

In patients with X-linked hypophosphatemia (XLH), conventional therapy with oral phosphate salts and active vitamin D has been associated with nephrocalcinosis. However, the nature of the relationships among XLH, its treatment, nephrocalcinosis, and kidney function remain poorly understood. Renal ultrasounds were performed and glomerular filtration rates were estimated (eGFR) at baseline in burosumab-naïve patients with XLH who participated in burosumab clinical trials (NCT02181764, NCT02526160, NCT02537431, NCT02163577, NCT02750618, NCT02915705) or enrolled in the XLH Disease Monitoring Program (XLH-DMP; NCT03651505). In this cross-sectional analysis, patient, disease, and treatment characteristics were described among patients with and without nephrocalcinosis. The analysis included 196 children (mean [SD] age 7.6 [4.0] yr) and 318 adults (40.3 [13.1] yr). Mean (SD) height z-score was -1.9 (1.2) for children and -2.3 (1.7) for adults. Nearly all children (97%) and adults (94%) had previously received conventional therapy. Nephrocalcinosis was detected in 22% of children and 38% of adults. In children, reduced eGFR <90mL/min/1.73m2 was more prevalent in those with nephrocalcinosis (25%) than in those without (11%), a finding that was not observed in adults. Children with nephrocalcinosis had lower mean values of TmP/GFR (p<.05), serum 1,25(OH)2D (p<.05), and eGFR (p<.001) and higher mean serum calcium concentrations (p<.05) than did those without nephrocalcinosis. Adults with nephrocalcinosis had lower mean serum phosphorus (p<.01) and 1,25(OH)2D (p<.05) concentrations than those without. Exploratory logistic regression analyses revealed no significant associations between the presence of nephrocalcinosis and other described patient or disease characteristics. Nephrocalcinosis was observed in nearly one-quarter of children and more than one-third of adults with XLH. Further study is needed to better understand the predictors and long-term consequences of nephrocalcinosis, with surveillance for nephrocalcinosis remaining important in the management of XLH.

An Integrated Review of Hepatorenal Syndrome

The purpose of this review was to go over and condense the intricate details that have been updated over time about the diagnosis, etiopathology, definition, and available treatments for hepatorenal syndrome. When individuals have decompensated liver disease, acute kidney injury might have multiple causes, including hormone replacement therapy (HRS). Type 1 and type 2 are the two clinical subtypes of hepatorenal syndrome. Lack of proteinuria, hematuria, or aberrant renal ultrasonography, as well as declining kidney function, are the basis for the diagnosis. Liver transplantation is the best treatment for cases of HRS, but because of the high death rate, very few people get one. In light of the improved understanding of the condition, more hepatorenal syndrome therapeutic options, including pharmacological and non-pharmacological techniques, are also explored.

Unique Variants of Megacalycosis on Magnetic Resonance Urography

To present a unique set of patients diagnosed with megacalycosis by magnetic resonance urography (MRU) to re-evaluate the definition of megacalycosis and provide a new perspective on diagnosis and treatment. A retrospective chart review of patients with megacalycosis as diagnosed by MRU was conducted. MRU was performed to determine the presence of obstruction, further visualize renal anatomy, and clarify the presence of megacalycosis. Patients who were asymptomatic and demonstrated no evidence of obstruction were managed with long-term observation through renal bladder ultrasonography, and symptomatic patients who showed evidence of obstruction (crossing vessels, abnormal renal transit time, or disparity in differential renal function of <40%) were treated surgically with a dismembered Anderson-Hynes pyeloplasty. Thirteen cases of megacalycosis were identified as diagnosed by MRU at our institution between 2007 and 2020. In 7 patients (54%), MRU revealed the simultaneous occurrence of obstruction and megacalycosis. In patients with obstruction (N=7), surgical intervention was required to correct the obstruction via robotic pyeloplasty. In patients without obstruction (N=6), conservative management was performed to monitor megacalycosis through long-term follow-up via routine ultrasounds. While megacalycosis has historically referred to the non-obstructive dilatation of the renal calyces, our study presents 7 cases of obstruction occurring simultaneously with megacalycosis as diagnosed by MRU. By expanding the designation of megacalycosis to include patients with obstruction, surgical treatment can be explored to prevent future renal colic and/or renal deterioration in those patients.