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Renal and genitourinary (GU) complaints are common reasons for presentation to the emergency department (ED). This article reviews the approach to renal, bladder, and testicular point-of-care ultrasound (POCUS) with specific discussions of commonly encountered ED pathology. It presents algorithms highlighting the clinical integration of renal and GU POCUS into the evaluation and management of these patients., Competing Interests: Disclosure D.J. Kim provides consultant services to Fujifilm Sonosite. C.R. Bell has received honoraria from Fujifilm Sonosite. G. Sheppard has nothing to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Sections stained in periodic acid-Schiff (PAS), periodic acid-methenamine silver (PAM), hematoxylin and eosin (H&E), and Masson's trichrome (MT) stain with minimal morphological discordance are helpful for pathological diagnosis in renal biopsy. Here, we propose an artificial intelligence-based re-stainer called PPHM-GAN (PAS, PAM, H&E, and MT-generative adversarial networks) with multi-stain to multi-stain transformation capability. We trained three GAN models on 512 × 512-pixel patches from 26 training cases. The model with the best transformation quality was selected for each pair of stain transformations by human evaluation. Frechet inception distances, peak signal-to-noise ratio, structural similarity index measure, contrast structural similarity, and newly introduced domain shift inception score were calculated as auxiliary quality metrics. We validated the diagnostic utility using 5120 × 5120 patches of ten validation cases for major glomerular and interstitial abnormalities. Transformed stains were sometimes superior to original stains for the recognition of crescent formation, mesangial hypercellularity, glomerular sclerosis, interstitial lesions, or arteriosclerosis. 23 of 24 glomeruli (95.83 %) from 9 additional validation cases transformed to PAM, PAS, or MT facilitated recognition of crescent formation. Stain transformations to PAM (p = 4.0E-11) and transformations from H&E (p = 4.8E-9) most improved crescent formation recognition. PPHM-GAN maximizes information from a given section by providing several stains in a virtual single-section view, and may change the staining and diagnostic strategy., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. Masataka Kawai has patent pending to University of Yamanashi., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Abstract: Malakoplakia is a rare inflammatory disease that most frequently affects the urinary tract. We present the case of a patient who had been receiving treatment for breast cancer, who later on went on to develop diffuse large B-cell lymphoma for which she was started on RCHOP therapy. It was during her treatment that she underwent a whole-body 18 F-FDG PET/CT for response evaluation and was incidentally diagnosed to have bilateral renal malakoplakia, which resolved after a prolonged course of antibiotic therapy., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Contrast-enhanced ultrasound (CEUS) is an advanced ultrasound (US) technique utilizing ultrasound contrast agents (UCAs) to provide detailed visualization of anatomic and vascular architecture, including the depiction of microcirculation. CEUS has been well-established in echocardiography and imaging of focal hepatic lesions and recent studies have also shown the utility of CEUS in non-hepatic applications like the urinary system. The updated guidelines by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) from 2018 describe the use of CEUS for non-hepatic applications. CEUS' excellent safety profile and spatial resolution make it a superior modality to conventional US and is often comparable and even superior to CECT in some instances. In comparison to other cross-sectional imaging modalities such as CECT or MRI, CEUS offers a safe (by virtue of non-nephrotoxic US contrast agents), accurate, cost-efficient, readily available, and a quick means of evaluation of multiple pathologies of the urinary system. CEUS also has the potential to reduce the overall economic burden on patients requiring long-term follow-up due to its low cost as compared to CT or MRI techniques. This comprehensive review focuses on the applications of CEUS in evaluating the urinary system from the kidneys to the urinary bladder. CEUS can be utilized in the kidney to evaluate complex cystic lesions, indeterminate lesions, pseudotumors (vs solid renal tumors), renal infections, and renal ischemic disorders. Additionally, CEUS has also been utilized in evaluating renal transplants. In the urinary bladder, CEUS is extremely useful in differentiating a bladder hematoma and bladder cancer when conventional US techniques show equivocal results. Quantitative parameters of time-intensity curves (TICs) of CEUS examinations have also been studied to stage and grade bladder cancers. Although promising, further research is needed to definitively stage bladder cancers and classify them as muscle-invasive or non-muscle invasive using quantitative CEUS to guide appropriate intervention. CEUS has been very effective in the classification of cystic renal lesions, however, further research is needed in differentiating benign from malignant renal masses., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

BACKGROUND The aim of this study was to investigate the clinical utility of ultrasound shear wave elastography (SWE) for assessment of renal fibrosis in post-renal transplant patients. MATERIAL AND METHODS We selected 183 patients who underwent renal transplantation. The complete dataset was randomly partitioned into a training cohort (128 cases) and a validation cohort (55 cases). All patients were subjected to SWE and renal allograft biopsy. The baseline data was compared using t-test, Z-test, or chi-square test. Through univariate and multivariate analyses, we identified independent risk factors influencing renal fibrosis after transplantation, a predictive model for post-transplant renal fibrosis was developed, and calibration curves, decision curve analyses, and ROC curves were generated. RESULTS Age, TST, Scr, GFR, and Emean showed significant differences (P<0.05). The C-index of the nomogram was 0.85, and the calibration curve and Hosmer-Lemeshow test demonstrated accurate diagnosis of fibrosis in both the training and validation sets (P>0.05). DCA showed that the prediction model effectively improved the diagnostic accuracy of fibrosis. The highest AUC of the nomogram for combined prediction of renal fibrosis in transplant patients was 0.902 in the training group and 0.871 in the validation group. These values were significantly higher compared to the AUCs of individual predictors (P<0.05). CONCLUSIONS Ultrasound SWE allows for early evaluation of renal fibrosis following transplantation. The prediction model, constructed by amalgamating other indicators, augments the accuracy and reliability of the prediction, providing more precise and accurate diagnostic and therapeutic recommendations for clinical practitioners.

Objectives: We aimed to evaluate the changes in renal cortical microperfusion and quantitative contrast-enhanced ultrasonography (CEUS) parameters after kidney transplantation, and to determine the evidence-based value of CEUS in predicting renal dysfunction., Methods: The Embase, MEDLINE, Web of Science, and Cochrane Library databases were searched for relevant studies published from 2000 to 2023 on the use of CEUS to assess the renal cortical microcirculation after kidney transplantation. Subject terms and related keywords were combined, and a meta-analysis and systematic review were performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines., Results: The search yielded six studies involving 451 patients with moderate to high overall quality. The peak intensity (standardized mean difference [SMD]: -0.64, 95% confidence interval [CI] -1.13 to -0.15, p = 0.01) of CEUS was significantly lower in patients with renal dysfunction than in those with stable renal function. However, the time to peak (SMD: 0.28, 95% CI 0.04 to 0.52, p = 0.02) was significantly shorter in patients with renal dysfunction than in those with stable renal function. The total renal cortical microperfusion and renal cortical perfusion intensity were decreased, and the perfusion time was prolonged, in patients with renal dysfunction after kidney transplantation., Conclusion: CEUS parameters can reflect real-time changes in renal cortical microperfusion, thus providing a basis for the early diagnosis of renal dysfunction after kidney transplantation., (© 2024 Wiley Periodicals LLC.)

Purpose: To investigate the renal fat deposition on Dixon-based magnetic resonance imaging (MRI) and to explore the predictive value of renal fat biomarkers of magnetic resonance (MR-RFBs) for early kidney damage in obesity., Methods: This prospective study included 56 obese volunteers and 47 non-obese healthy volunteers. All volunteers underwent renal magnetic resonance examinations. The differences in MR-RFBs [including renal proton density fat fraction (PDFF), renal sinus fat volume (RSFV), and perirenal fat thickness (PRFT)] measured on Dixon-based MRI between the obese and non-obese volunteers were analyzed using a general linear model, taking sex, age, diabetes, and hypertension as covariates. The relationship between estimated glomerular filtration rate (eGFR) and demographic, laboratory, and imaging parameters in obese volunteers was examined by correlation analysis., Results: Obese volunteers had higher MR-RFBs than non-obese volunteers after controlling for confounders (all p < 0.001). Renal PDFF (r = - 0.383; p = 0.004), RSFV (r = - 0.368; p = 0.005), and PRFT (r = - 0.451; p < 0.001) were significantly negatively correlated with eGFR in obesity. After adjusting for age, sex, body mass index, diabetes, hypertension, visceral adipose tissue, subcutaneous adipose tissue, renal PDFF, and RSFV, PRFT remained independently negatively associated with eGFR (β = - 0.587; p = 0.003)., Conclusions: All MR-RFBs are negatively correlated with eGFR in obesity. The MR-RFBs, especially PRFT, may have predictive value for early kidney damage in obesity., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objectives: To investigate whether shear wave elastography (SWE) can accurately identify interstitial fibrosis and tubular atrophy (IFTA) in chronic renal allograft injury (CRAI) and whether it can differentiate between different grades of IFTA., Materials and Methods: Prospective observational study on renal transplant recipients who presented with CRAI. Patient selection was done on the basis of clinical presentation, serum creatinine, and eGFR levels. Biopsy and SWE were performed and SWE values were correlated with histopathological findings according to Banff schema. Receiver operating characteristic (ROC) was also analyzed to assess the diagnostic efficacy of SWE., Results: Sxity-one patients were evaluated. Ten patients had no IFTA, 33 patients had mild IFTA, 16 patients had moderate IFTA, and 2 patients had severe IFTA. Mean parenchymal stiffness values in no IFTA, mild IFTA, moderate IFTA and severe IFTA were 39.86 ± 2.17 kPa (3.64 ± 0.09 m/s), 41.59 ± 3.36 kPa (3.71 ± 0.15 m/s), 47.59 ± 3.34 kPa (3.98 ± 0.14 m/s), and 53.83 ± 1.41 kPa (4.25 ± 0.03 m/s), respectively. SWE values of parenchymal stiffness reached statistical significance to differentiate between mild, moderate, and severe IFTA. ROC analysis revealed cut-off values of 45.09 kPa (3.89 m/s) to differentiate between mild IFTA and moderate IFTA, 52.06 kPa (4.18 m/s) to differentiate between moderate IFTA and severe IFTA with acceptable sensitivity and specificity., Conclusion: SWE is a non-invasive and cost-effective imaging tool to evaluate the disease status of renal allografts affected by CRAI. Thus, it can be of paramount importance if added to the regular follow-up imaging protocol of renal allograft along with grayscale and Doppler imaging., (© 2024 American Institute of Ultrasound in Medicine.)

Diffusion measurements in the kidney are affected not only by renal microstructure but also by physiological processes (i.e., glomerular filtration, water reabsorption, and urine formation). Because of the superposition of passive tissue diffusion, blood perfusion, and tubular pre-urine flow, the limitations of the monoexponential apparent diffusion coefficient (ADC) model in assessing pathophysiological changes in renal tissue are becoming apparent and motivate the development of more advanced diffusion-weighted imaging (DWI) variants. These approaches take advantage of the fact that the length scale probed in DWI measurements can be adjusted by experimental parameters, including diffusion-weighting, diffusion gradient directions and diffusion time. This forms the basis by which advanced DWI models can be used to capture not only passive diffusion effects, but also microcirculation, compartmentalization, tissue anisotropy. In this review, we provide a comprehensive overview of the recent advancements in the field of renal DWI. Following a short introduction on renal structure and physiology, we present the key methodological approaches for the acquisition and analysis of renal DWI data, including intravoxel incoherent motion (IVIM), diffusion tensor imaging (DTI), non-Gaussian diffusion, and hybrid IVIM-DTI. We then briefly summarize the applications of these methods in chronic kidney disease and renal allograft dysfunction. Finally, we discuss the challenges and potential avenues for further development of renal DWI. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2., (© 2023 International Society for Magnetic Resonance in Medicine.)

Kidney diseases pose a significant global health challenge, requiring precise diagnostic tools to improve patient outcomes. This study addresses this need by investigating three main categories of renal diseases: kidney stones, cysts, and tumors. Utilizing a comprehensive dataset of 12,446 CT whole abdomen and urogram images, this study developed an advanced AI-driven diagnostic system specifically tailored for kidney disease classification. The innovative approach of this study combines the strengths of traditional convolutional neural network architecture (AlexNet) with modern advancements in ConvNeXt architectures. By integrating AlexNet's robust feature extraction capabilities with ConvNeXt's advanced attention mechanisms, the paper achieved an exceptional classification accuracy of 99.85%. A key advancement in this study's methodology lies in the strategic amalgamation of features from both networks. This paper concatenated hierarchical spatial information and incorporated self-attention mechanisms to enhance classification performance. Furthermore, the study introduced a custom optimization technique inspired by the Adam optimizer, which dynamically adjusts the step size based on gradient norms. This tailored optimizer facilitated faster convergence and more effective weight updates, imporving model performance. The model of this study demonstrated outstanding performance across various metrics, with an average precision of 99.89%, recall of 99.95%, and specificity of 99.83%. These results highlight the efficacy of the hybrid architecture and optimization strategy in accurately diagnosing kidney diseases. Additionally, the methodology of this paper emphasizes interpretability and explainability, which are crucial for the clinical deployment of deep learning models., (© 2024. The Author(s).)

Rationale: The current diagnostic approach for urinary tract urothelial carcinoma (UTUC) relies on symptoms and imaging. Nevertheless, the diagnosis can be challenging in advanced cases presenting with atypical imaging and symptoms. This article presents an unreported case with atypical imaging and symptoms to provide some experience in diagnosing advanced UTUC., Patient Concerns: A 55-year-old male patient was admitted to the hospital with a 2-month history of persistent left scrotal pain and intermittent left lower back pain., Diagnoses: Computed tomography and magnetic resonance imaging revealed a left kidney infection. Paradoxically, the patient did not present with a fever, and the white blood cell count was within normal limits. To further clarify the diagnosis, urine cytology was performed. Surprisingly, malignant tumor cells were discovered. The diagnosis of UTUC was considered., Interventions: The patient underwent radical tumor resection., Outcomes: The surgery was successfully performed. The patient received regular chemotherapy after surgery. No recurrence was found during the follow-up., Lessons: This case is a rare and enlightening clinical scenario. When imaging reveals renal infection accompanied by varicocele or renal vein embolism, it is crucial to consider the possibility of advanced UTUC., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background and Objective: In renal disease research, precise glomerular disease diagnosis is crucial for treatment and prognosis. Currently reliant on invasive biopsies, this method bears risks and pathologist-dependent variability, yielding inconsistent results. There is a pressing need for innovative diagnostic tools that enhance traditional methods, streamline processes, and ensure accurate and consistent disease detection., Methods: In this study, we present an innovative Convolutional Neural Networks-Vision Transformer (CVT) model leveraging Transformer technology to refine glomerular disease diagnosis by fusing spectral and spatial data, surpassing traditional diagnostic limitations. Using interval sampling, preprocessing, and wavelength optimization, we also introduced the Gramian Angular Field (GAF) method for a unified representation of spectral and spatial characteristics., Results: We captured hyperspectral images ranging from 385.18 nm to 1009.47 nm and employed various methods to extract sample features. Initial models based solely on spectral features achieved a accuracy of 85.24 %. However, the CVT model significantly outperformed these, achieving an average accuracy of 94 %. This demonstrates the model's superior capability in utilizing sample data and learning joint feature representations., Conclusions: The CVT model not only breaks through the limitations of existing diagnostic techniques but also showcases the vast potential of non-invasive, high-precision diagnostic technology in supporting the classification and prognosis of complex glomerular diseases. This innovative approach could significantly impact future diagnostic strategies in renal disease research., Concise Abstract: This study introduces a transformative hyperspectral image classification model leveraging a Transformer to significantly improve glomerular disease diagnosis accuracy by synergizing spectral and spatial data, surpassing conventional methods. Through a rigorous comparative analysis, it was determined that while spectral features alone reached a peak accuracy of 85.24 %, the novel Convolutional Neural Network-Transformer (CVT) model's integration of spatial-spectral features via the Gramian Angular Field (GAF) method markedly enhanced diagnostic precision, achieving an average accuracy of 94 %. This methodological innovation not only overcomes traditional diagnostic limitations but also underscores the potential of non-invasive, high-precision technologies in advancing the classification and prognosis of complex renal diseases, setting a new benchmark in the field., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest or financial disclosures related to this research. The study was conducted independently, and the results are presented objectively without any external influence., (Copyright © 2024. Published by Elsevier B.V.)

Objective: Retrospectively evaluate multimodality imaging features of perinephric myxoid pseudotumor of fat (PMPTF)., Methods: Institutional cases of PMPTF with CT, MRI and/or ultrasound evaluation from 1/1/2020 to 9/1/2023 were retrospectively reviewed. Patient demographics and clinical history were reviewed, and imaging features recorded., Results: 14 patients with pathologically-proven PMPTF were identified (11 M, 3 F; mean age 66.7 ± 17.0 years; range 40-87 years). Three patients (18%) had bilateral lesions; a total of 17 PMPTFs were reviewed. 15/17 (88%) were biopsy-proven; two cases were diagnosed by imaging only in patients with a contralateral biopsy-proven PMPTF. All evaluable specimens were negative for MDM2 amplification. 11/17 (65%) occurred in patients with renal disease, including 4/17 (24%) in patients with renal transplant. 100% (17/17) had CT, 11/17 (65%) MRI, and 6/17 (35%) ultrasound. The mean largest lesion dimension was 10.9 ± 4.6 cm (range 4.3-17.0 cm). Of cases involving native kidneys, 7/13 (54%) presented as multifocal perinephric masses and 5/13 (38%) as a solitary perinephric mass. All four transplant cases presented as infiltrative-appearing masses involving the renal sinus with lesser perinephric involvement. 14/17 (82%) lesions contained macroscopic fat on CT and MRI and 3/17 (18%) showed no macroscopic fat, all involving renal transplants. All cases with MRI demonstrated T2 hyperintensity with signal dropout on opposed-phase imaging. 11/13 (85%) PMPTF showed no or equivocal CT enhancement. Enhancement was better seen on MRI in all cases evaluated by both CT and MRI. Of the six PMPTFs imaged by ultrasound, four (67%) were heterogeneously hypoechoic and two (33%) had mixed regions of hypo-, iso- and hyperechogenicity relative to adjacent renal parenchyma., Conclusions: PMPTF is a rare, benign, and underrecognized lesion that may mimic malignancy, particularly retroperitoneal well-differentiated liposarcoma. The imaging features of this unusual pseudosarcoma differ in native and transplanted kidneys. Improved awareness of this entity will facilitate appropriate patient management and avoid unnecessary intervention., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Although kidney diseases have a high prevalence, initial recognition and diagnosis of renal disease are complicated in avian medicine., Objective: The aim of this study is to assess the intraosseous excretory urography (IOEU) in order to introduce a new method for evaluation of kidney's function in broilers as a primary model of birds., Methods: A total of 10 male broiler chickens at the age of 20 days were included and evaluated with plain and serial post-contrast radiography and computed tomography (CT) scan to check the time and concentration of the contrast media (CM) passage from the kidney. In the next step, after the nephropathy induction with gentamicin, plain and serial post-contrast radiography and CT scan were repeated. After the necropsy, kidney samples were sent for histopathology evaluation, and statistical analysis of data obtained from image analysis was conducted., Results: After nephropathy induction, all of the chickens exhibited increase in kidney size and in histopathological evaluation, all the samples (30 of 30) showed severe tubular necrosis and mild glomerulopathy. In the IOEU, the average time to create the maximum concentration of CM, the average time to decrease the CM concentration from the kidney and the time of the complete clearance of CM indicated a significant incensement after nephropathy compared to the time before it., Conclusion: Intraosseous excretory urography (IOEU) is a safe contrast imaging modality and can be useful in the assessment of the urinary system in chickens to check the changes in kidney size and function., (© 2024 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

The kidney is an abdominal organ in the human body that supports filtering excess water and waste from the blood. Kidney diseases generally occur due to changes in certain supplements, medical conditions, obesity, and diet, which causes kidney function and ultimately leads to complications such as chronic kidney disease, kidney failure, and other renal disorders. Combining patient metadata with computed tomography (CT) images is essential to accurately and timely diagnosing such complications. Deep Neural Networks (DNNs) have transformed medical fields by providing high accuracy in complex tasks. However, the high computational cost of these models is a significant challenge, particularly in real-time applications. This paper proposed SpinalZFNet, a hybrid deep learning approach that integrates the architectural strengths of Spinal Network (SpinalNet) with the feature extraction capabilities of Zeiler and Fergus Network (ZFNet) to classify kidney disease accurately using CT images. This unique combination enhanced feature analysis, significantly improving classification accuracy while reducing the computational overhead. At first, the acquired CT images are pre-processed using a median filter, and the pre-processed image is segmented using Efficient Neural Network (ENet). Later, the images are augmented, and different features are extracted from the augmented CT images. The extracted features finally classify the kidney disease into normal, tumor, cyst, and stone using the proposed SpinalZFNet model. The SpinalZFNet outperformed other models, with 99.9% sensitivity, 99.5% specificity, precision 99.6%, 99.8% accuracy, and 99.7% F1-Score in classifying kidney disease., (© 2024. The Author(s).)

Objectives: Fibrosis is the final common pathway for chronic kidney disease and the best predictor for disease progression. Besides invasive biopsies, biomarkers for its detection are lacking. To address this, we used hyperpolarized 13 C-pyruvate MRI to detect the metabolic changes associated with fibrogenic activity of myofibroblasts., Materials and Methods: Hyperpolarized 13 C-pyruvate MRI was performed in 2 pig models of kidney fibrosis (unilateral ureteral obstruction and ischemia-reperfusion injury). The imaging data were correlated with histology, biochemical, and genetic measures of metabolism and fibrosis. The porcine experiments were supplemented with cell-line experiments to inform the origins of metabolic changes in fibrogenesis. Lastly, healthy and fibrotic human kidneys were analyzed for the metabolic alterations accessible with hyperpolarized 13 C-pyruvate MRI., Results: In the 2 large animal models of kidney fibrosis, metabolic imaging revealed alterations in amino acid metabolism and glycolysis. Conversion from hyperpolarized 13 C-pyruvate to 13 C-alanine decreased, whereas conversion to 13 C-lactate increased. These changes were shown to reflect profibrotic activity in cultured epithelial cells, macrophages, and fibroblasts, which are important precursors of myofibroblasts. Importantly, metabolic MRI using hyperpolarized 13 C-pyruvate was able to detect these changes earlier than fibrosis-sensitive structural imaging. Lastly, we found that the same metabolic profile is present in fibrotic tissue from human kidneys. This affirms the translational potential of metabolic MRI as an early indicator of fibrogenesis associated metabolism., Conclusions: Our findings demonstrate the promise of hyperpolarized 13 C-pyruvate MRI for noninvasive detection of fibrosis development, which could enable earlier diagnosis and intervention for patients at risk of kidney fibrosis., Competing Interests: Conflicts of interest and sources of funding: This study was funded by The Lundbeck Foundation and The Karen Elise Jensen Foundation., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

The superior lumbar triangle is formed by the erector spinae muscles medially, internal oblique muscles laterally and the 12th rib superiorly. Herniation through this triangle can be congenital or acquired (primary or secondary). The contents of the hernial sac commonly include retroperitoneal fat, kidneys, ascending or descending colon, small intestines, stomach, spleen, etc. We present a case of an infant with congenital herniation of the left kidney through the superior lumbar triangle with an incidentally detected closed spinal tube defect. The anatomy of the lumbar triangle and a literature review of the associated hernia have been briefly described in this article., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Noninvasive fluorescence imaging of renal function is a valuable technique for understanding kidney disease progression and the development of renal medicine. This technique requires sensitive imaging probes for reporting renal dysfunction accurately at early stage. Herein, a molecularly engineered imaging probe (800CW-PEG 45 -COOH) was synthesized by simply PEGylating conventional near-infrared fluorophore IRDye800CW with NH 2 -PEG 45 -COOH (molecular weight ∼2100 Da) for early detection and staging of renal dysfunction through noninvasive real-time kidney imaging. 800CW-PEG 45 -COOH not only cleared through the kidney efficiently (>90% injection dosage at 24 h postinjection) but was also found to be freely filtered by glomeruli without renal tubular reabsorption and secretion. Despite this simple construction strategy, the transport of 800CW-PEG 45 -COOH within the kidneys was extremely sensitive to the alteration of the glomerular filtration rate (GFR), which enabled it to detect renal dysfunction much earlier than commonly used serum biomarkers and stage kidney function impairments (mild vs severe dysfunction) via imaging-based kidney clearance kinetics. This work not only provides a promising optical imaging probe for the noninvasive evaluation of kidney function but also highlights the utility of PEGylation in enhancing the performance of conventional organic dyes in biomedical applications.

Ultrasound is the first-line imaging modality used in patients with suspected renovascular disease. Common indications include renovascular hypertension and unexplained renal dysfunction. We review the ultrasound imaging findings of various pathologies involving the renal vessels, including the renal arteries (atherosclerotic stenosis, fibromuscular dysplasia, dissection, arteriovenous fistula, and aneurysm) and veins (tumor and bland thrombus as well as vascular compression syndromes). The current role of renal artery stent placement for atherosclerotic stenosis is also discussed., (© 2024 American Institute of Ultrasound in Medicine.)

Background: Accurate and noninvasive assessment of split renal dysfunction is crucial, while there is lack of corresponding method clinically., Purpose: To investigate the feasibility of using diffusion-weighted imaging (DWI)-based radiomics models to evaluate split renal dysfunction., Methods: We enrolled patients with impaired and normal renal function undergoing renal DWI examination. Glomerular filtration rate (GFR, mL/min) was measured using 99mTc-DTPA scintigraphy, which is reference standard of GFR measurement. The kidneys were classified into normal (GFR ≥40), mildly impaired (20≤ GFR < 40), moderately impaired (10≤ GFR < 20), and severely impaired (GFR < 10) renal function groups. Optimized subsets of radiomics features were selected from renal DWI images and radiomics scores (Rad-score) calculated to discriminate groups with different renal function. The radiomics model (Rad-score based) was developed in a training cohort and validated in a test cohort. Evaluations were conducted on the discrimination, calibration, and clinical application of the method., Results: The final analysis included 330 kidneys. Logistic regression was used to develop three radiomics models, model A, B, and C, which were used to distinguish normal from impaired, mild from moderate, and moderate from severe renal function, respectively. The area under the curve of the three models were 0.822, 0.704, and 0.887 in the training cohort and 0.843, 0.717, and 0.897 in the test cohort, respectively, indicating efficient discrimination performance., Conclusions: DWI-based radiomics models have potential for evaluating split renal dysfunction and discriminating between normal and impaired renal function groups and their subgroups., (© 2024 American Association of Physicists in Medicine.)

Molecular optical probes play pivotal roles in in vivo imaging of biomarkers associated to kidney diseases. Relying on structural tunability and high fluorescence quantum yields, versatile optical probes have been constructed on cyanine or hemicyanine-based scaffold in recent years. This review summaries the recent progress on the development of optical probes for imaging of kidney diseases, particularly through near-infrared fluorescence, chemiluminescence and photoacoustic imaging modalities. The chemical design and sensing mechanisms are discussed along with applications in the detection of renal cell carcinoma and acute kidney injury. This progress provides insights and directions for the development of next generation kidney-targeted probes and for pushing their further applications in preclinical and clinical research., (© 2024 Wiley-VCH GmbH.)

Spontaneous renal hemorrhage (SRH) is a diagnostic challenge and a significant cause of morbidity, and sometimes mortality. Early identification is essential to institute lifesaving and reno-protective interventions. In this review, we classify spontaneous renal hemorrhage by location, presentation and etiology. We also discuss the diagnostic approach to renal hemorrhage and optimum imaging modalities to arrive at the diagnosis. Finally, we review strategies to avoid missing a diagnosis of SRH and discuss the pitfalls of imaging in the presence of renal hemorrhage., (© 2024. The Author(s), under exclusive licence to American Society of Emergency Radiology (ASER).)

Ultrasound is a widespread imaging modality, with special application in medical fields such as nephrology. However, automated approaches for ultrasound renal interpretation still pose some challenges: (1) the need for manual supervision by experts at various stages of the system, which prevents its adoption in primary healthcare, and (2) their limited considered taxonomy (e.g., reduced number of pathologies), which makes them unsuitable for training practitioners and providing support to experts. This paper proposes a fully automated computer-aided diagnosis system for ultrasound renal imaging addressing both of these challenges. Our system is based in a multi-task architecture, which is implemented by a three-branched convolutional neural network and is capable of segmenting the kidney and detecting global and local pathologies with no need of human interaction during diagnosis. The integration of different image perspectives at distinct granularities enhanced the proposed diagnosis. We employ a large (1985 images) and demanding ultrasound renal imaging database, publicly released with the system and annotated on the basis of an exhaustive taxonomy of two global and nine local pathologies (including cysts, lithiasis, hydronephrosis, angiomyolipoma), establishing a benchmark for ultrasound renal interpretation. Experiments show that our proposed method outperforms several state-of-the-art methods in both segmentation and diagnosis tasks and leverages the combination of global and local image information to improve the diagnosis. Our results, with a 87.41% of AUC in healthy-pathological diagnosis and 81.90% in multi-pathological diagnosis, support the use of our system as a helpful tool in the healthcare system., (© 2024. The Author(s).)

Kidney diseases have become an important global health concern due to their high incidence, inefficient diagnosis, and poor prognosis. Devising direct methods, especially imaging means, to assess renal function is the key for better understanding the mechanisms of various kidney diseases and subsequent development of effective treatment. Herein, we developed a fluorinated ferrous chelate-based sensitive probe, 1,7-DO2A-Fe(II)-F18 (Probe 1 ), for 19 F magnetic resonance imaging (MRI). This highly fluorinated probe (containing 18 chemically equivalent 19 F atoms with a fluorine content at 35 wt %) achieves a 15-time enhancement in signal intensity compared with the fluorine-containing ligand alone due to the appropriately regulated 19 F relaxation times by the ferrous ion, which significantly increases imaging sensitivity and reduces acquisition time. Owing to its high aqueous solubility, biostability, and biocompatibility, this probe could be rapidly cleared by kidneys, which provides a means for monitoring renal dysfunction via 19 F MRI. With this probe, we accomplish in vivo imaging of the impaired renal dysfunction caused by various kidney diseases including acute kidney injury, unilateral ureteral obstruction, and renal fibrosis at different stages. Our study illustrates the promising potential of Probe 1 for in vivo real-time visualization of kidney dysfunction, which is beneficial for the study, diagnosis, and even stratification of different kidney diseases. Furthermore, the design strategy of our probe is inspiring for the development of more high-performance 19 F MRI probes for monitoring various biological processes.

Glomerulus morphology on renal pathology images provides valuable diagnosis and outcome prediction information. To provide better care, an efficient, standardized, and scalable method is urgently needed to optimize the time-consuming and labor-intensive interpretation process by renal pathologists. This paper proposes a deep convolutional neural network (CNN)-based approach to automatically detect and classify glomeruli with different stains in renal pathology images. In the glomerulus detection stage, this paper proposes a flattened Xception with a feature pyramid network (FX-FPN). The FX-FPN is employed as a backbone in the framework of faster region-based CNN to improve glomerulus detection performance. In the classification stage, this paper considers classifications of five glomerulus morphologies using a flattened Xception classifier. To endow the classifier with higher discriminability, this paper proposes a generative data augmentation approach for patch-based glomerulus morphology augmentation. New glomerulus patches of different morphologies are generated for data augmentation through the cycle-consistent generative adversarial network (CycleGAN). The single detection model shows the F 1 score up to 0.9524 in H&E and PAS stains. The classification result shows that the average sensitivity and specificity are 0.7077 and 0.9316, respectively, by using the flattened Xception with the original training data. The sensitivity and specificity increase to 0.7623 and 0.9443, respectively, by using the generative data augmentation. Comparisons with different deep CNN models show the effectiveness and superiority of the proposed approach., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Early detection of renal fibrosis (RF) is very important given that it is irreversible when it progresses to the terminal stage. A key marker of RF pathogenesis is activation of myomyofibroblasts, and its targeted imaging may be a promising approach for early detection of RF, but no study has directly imaged activation of renal myomyofibroblasts. Cu 2+ plays a major role in the fibrotic activity of myofibroblasts. Herein, inspired by that Cu 2+ can complex with bovine serum albumin (BSA), BSA-Ag 2 S quantum dots (QDs) with aggregation-induced emission (AIE) property are synthesized. Then BSA-Ag 2 S QDs are modified by chitosan (CS) with renal targeting and hyaluronic acid (HA) with myofibroblast targeting to obtain the AIE assay system (QDs@CS@HA). The system is simple to synthesize, and produces a rapid NIR fluorescence signal turn-on response and a low detection limit of 75 × 10 -9 m to Cu 2+ . In addition, cellular and animal experiments have shown that QDs@CS@HA has good biosafety and cell-targeted imaging capability for RF. Based on the successful application of QDs@CS@HA and the mechanism of RF progression in early RF detection, it is expected that QDs@CS@HA may detect RF before the appearance of clinical symptoms., (© 2024 Wiley‐VCH GmbH.)

Radionuclide imaging plays a critical role in the diagnosis and management of kidney obstruction. However, most practicing radiologists in US hospitals have insufficient time and resources to acquire training and experience needed to interpret radionuclide images, leading to increased diagnostic errors. To tackle this problem, Emory University embarked on a study that aims to develop a computer-assisted diagnostic (CAD) tool for kidney obstruction by mining and analyzing patient data comprised of renogram curves, ordinal expert ratings on the obstruction status, pharmacokinetic variables, and demographic information. The major challenges here are the heterogeneity in data modes and the lack of gold standard for determining kidney obstruction. In this article, we develop a statistically principled CAD tool based on an integrative latent class model that leverages heterogeneous data modalities available for each patient to provide accurate prediction of kidney obstruction. Our integrative model consists of three sub-models (multilevel functional latent factor regression model, probit scalar-on-function regression model, and Gaussian mixture model), each of which is tailored to the specific data mode and depends on the unknown obstruction status (latent class). An efficient MCMC algorithm is developed to train the model and predict kidney obstruction with associated uncertainty. Extensive simulations are conducted to evaluate the performance of the proposed method. An application to an Emory renal study demonstrates the usefulness of our model as a CAD tool for kidney obstruction., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. [br]For permissions, please e-mail: journals.permissions@oup.com.)

Normal canine kidneys are relatively homogeneous soft tissue attenuating structures on nonenhanced CT images. However, visible differences in attenuation between the renal crest and medulla are occasionally observed. This finding and its potential clinical implications have not been previously investigated. This study aimed to estimate the prevalence of renal crest hyperattenuation (RCH) and investigate possible associations with signalment and laboratory parameters. Abdominal CT studies from 100 dogs, with biochemistry and urinalysis data obtained within 48 h before the CT acquisition, were categorized by two radiologists into those with and without visible RCH. The attenuation in Hounsfield units (HU) of the renal crest and renal medulla were measured. Signalment, biochemical, and urinalysis data were analyzed for associations with RCH. Correlation coefficients were calculated for measured HU and associated continuous parameters. Prevalence of RCH was 42.42% (42/99 dogs, 95% CI, 33-52%). Urinary specific gravity (USG) was significantly different between dogs with and without RCH (P = .034). Weak positive correlations were identified between left and right renal crest attenuation and USG (r = 0.233 and 0.253, respectively; P = .05). Renal crest hyperattenuation is a common finding in dogs undergoing abdominal CT. Although the correlation between the USG and renal crest HU is weak, the dogs with RCH have significantly higher USG. Renal crest hyperattenuation might, therefore, not be associated with renal insufficiency. No other specific associations of RCH were identified with parameters typically altered in a variety of diseases. Further investigation may be warranted for its relevance to specific diseases or if it indeed represents a physiological variant., (© 2024 The Authors. Veterinary Radiology & Ultrasound published by Wiley Periodicals LLC on behalf of American College of Veterinary Radiology.)

A range of conditions involving the kidneys and urinary bladder can cause organ-threatening complications that are preventable if diagnosed promptly with diagnostic imaging. Common imaging modalities include either computed tomography or diagnostic ultrasound. Traditionally, ultrasound of the kidney-genitourinary system has required consultative teams consisting of a sonographer performing image acquisition and a radiologist performing image interpretation. However, diagnostic point-of-care ultrasound (POCUS) has recently emerged as a useful tool to troubleshoot acute kidney injury at the bedside. Studies have shown that non-radiologists can be trained to perform diagnostic POCUS of the kidneys and bladder with high accuracy for a set number of important conditions. Currently, diagnostic POCUS of the kidney-genitourinary system remains underused in actual clinical practice. This is likely because image acquisition for this organ system is unfamiliar to most clinicians in specialties that encounter acute kidney injury, including primary care, emergency medicine, intensive care, anesthesiology, nephrology, and urology. To address this multi-specialty educational gap, this narrative review was developed by a multi-disciplinary group to provide a specialty-agnostic framework for kidney-genitourinary POCUS image acquisition: indications/contraindications, patient positioning, transducer selection, acquisition sequence, and exam limitations. Finally, we describe foundational concepts in kidney-genitourinary ultrasound image interpretation, including key abnormal findings that every bedside clinician performing this modality should know.

Background: Sarcoidosis is a systemic disease that can affect multiple organs. While pulmonary sarcoidosis is most commonly observed, renal sarcoidosis occurs less frequently. We herein report a case of sarcoidosis with an exceptionally rare distribution including renal lesions., Case Presentation: A 51-year-old Japanese female was referred because of bilateral parotid swelling and renal dysfunction. Computed tomography scan showed the swelling of bilateral kidneys, parotid glands, and uterus. Ga scintigraphy also showed remarkable accumulation in these organs. Renal biopsy and cytological evaluations of parotid gland and uterus were performed and she was diagnosed as sarcoidosis of these organs. Treatment was initiated with prednisolone 40 mg/day and then renal dysfunction subsequently improved. In addition, the swelling of parotid glands and uterus improved and Ga accumulation in each organ had disappeared., Conclusion: This is a first case of renal sarcoidosis complicated by parotid glands and uterus lesions. Pathological findings and the reactivity observed in Ga scintigraphy indicated the presence of lesions in these organs., (© 2024. The Author(s).)

Background: Identifying the cause of renal allograft dysfunction is important for the clinical management of kidney transplant recipients., Purpose: To evaluate the diagnostic efficiency of diffusion tensor imaging (DTI) for identifying allografts with acute rejection (AR) and chronic allograft nephropathy (CAN)., Study Type: Prospective., Subjects: Seventy-seven renal transplant patients (aged 42.5 ± 9.5 years), including 29 patients with well-functioning stable allografts (Control group), 25 patients diagnosed with acute rejection (AR group), and 23 patients diagnosed with chronic allograft nephropathy (CAN group)., Field Strength/sequence: 1.5 T/T2-weighted imaging and DTI., Assessment: The serum creatinine, proteinuria, pathologic results, and fractional anisotropy (FA) values were obtained and compared among the three groups., Statistical Test: One-way analysis of variance; correlation analysis; independent-sample t-test; intraclass correlation coefficients and receiver operating characteristic curves. Statistical significance was set to a P-value <0.05., Results: The AR and CAN groups presented with significantly elevated serum creatinine as compared with the Control group (191.8 ± 181.0 and 163.1 ± 115.8 μmol/L vs. 82.3 ± 20.9 μmol/L). FA decreased in AR group (cortical/medullary: 0.13 ± 0.02/0.31 ± 0.07) and CAN group (cortical/medullary: 0.11 ± 0.02/0.27 ± 0.06), compared with the Control group (cortical/medullary: 0.15 ± 0.02/0.35 ± 0.05). Cortical FA in the AR group was higher than in the CAN group. The area under the curve (AUC) for identifying AR from normal allografts was 0.756 and 0.744 by cortical FA and medullary FA, respectively. The AUC of cortical FA and medullary FA for differentiating CAN from normal allografts was 0.907 and 0.830, respectively. The AUC of cortical FA and medullary FA for distinguishing AR and CAN from normal allografts was 0.828 and 0.785, respectively. Cortical FA was able to distinguish between AR and CAN with an AUC of 0.728., Data Conclusion: DTI was able to detect patients with dysfunctional allografts. Cortical FA can further distinguish between AR and CAN., Evidence Level: 2 TECHNICAL EFFICACY: Stage 2., (© 2023 International Society for Magnetic Resonance in Medicine.)

Background: Obesity is associated with metabolic syndrome and fat accumulation in various organs such as the liver and the kidneys. Our goal was to assess, using magnetic resonance imaging (MRI) Dual-Echo phase sequencing, the association between liver and kidney fat deposition and their relation to obesity., Methods: We analyzed MRI scans of individuals who were referred to the Chaim Sheba Medical Center between December 2017 and May 2020 to perform a study for any indication. For each individual, we retrieved from the computerized charts data on sex, and age, weight, height, body mass index (BMI), systolic and diastolic blood pressure (BP), and comorbidities (diabetes mellitus, hypertension, dyslipidemia)., Results: We screened MRI studies of 399 subjects with a median age of 51 years, 52.4% of whom were women, and a median BMI 24.6 kg/m 2 . We diagnosed 18% of the participants with fatty liver and 18.6% with fat accumulation in the kidneys (fatty kidneys). Out of the 67 patients with fatty livers, 23 (34.3%) also had fatty kidneys, whereas among the 315 patients without fatty livers, only 48 patients (15.2%) had fatty kidneys ( p < 0.01). In comparison to the patients who did not have a fatty liver or fatty kidneys ( n = 267), those who had both ( n = 23) were more obese, had higher systolic BP, and were more likely to have diabetes mellitus. In comparison to the patients without a fatty liver, those with fatty livers had an adjusted odds ratio of 2.91 (97.5% CI; 1.61-5.25) to have fatty kidneys. In total, 19.6% of the individuals were obese (BMI ≥ 30), and 26.1% had overweight (25 < BMI < 30). The obese and overweight individuals were older and more likely to have diabetes mellitus and hypertension and had higher rates of fatty livers and fatty kidneys. Fat deposition in both the liver and the kidneys was observed in 15.9% of the obese patients, in 8.3% of the overweight patients, and in none of those with normal weight. Obesity was the only risk factor for fatty kidneys and fatty livers, with an adjusted OR of 6.3 (97.5% CI 2.1-18.6)., Conclusions: Obesity is a major risk factor for developing a fatty liver and fatty kidneys. Individuals with a fatty liver are more likely to have fatty kidneys. MRI is an accurate modality for diagnosing fatty kidneys. Reviewing MRI scans of any indication should include assessment of fat fractions in the kidneys in addition to that of the liver.

Purpose: Ultrasound-guided percutaneous biopsy (USPB) of the native kidneys is the preferred diagnostic method for several nephrological conditions in both adult and pediatric populations. Conventionally, native kidney biopsies are conducted with patients in the prone position (PP). However, an alternative approach involving the supine oblique antero-lateral position (SALP) has been explored, particularly for individuals who are obese, elderly, or critically ill., Methods: This study aimed to assess the feasibility and outcomes of USPB performed in SALP with a Free-Flank setting (FF-SALP) in pediatric patients (Group A) compared to adults (Group B). Data from kidney biopsies conducted between 2008 and 2021 were gathered. The study focused on the safety and the prevalence of biopsy samples containing a minimum of 10 glomeruli, histopathological yield in both groups., Results: Complication rates were low in both groups (5.6% vs. 3.7%; p = 0.454), without major complications noted. The pediatric group achieved a significantly higher mean number of glomeruli per biopsy compared to the adult group (20.6 ± 12.3 vs. 15.7 ± 9.4; p < 0.001). However, when evaluating the minimum threshold of 10 glomeruli (76.3% vs. 68.5%; p = 0.072) and histopathologic yield (95.3% vs. 93.5%; p = 0.408), no differences were observed between groups., Conclusion: USPB of native kidneys in the FF-SALP position is a safe and effective method for tissue sampling in patients with parenchymal disease. It demonstrated comparable diagnostic yields and complication rates in the pediatric and adult populations, providing advantages in terms of airway management, making it particularly useful for pediatric patients that require general anesthesia., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Renal diseases in dogs can be diagnosed effectively using B-mode ultrasound. Point shear wave elastography (pSWE) has demonstrated usefulness in diagnosing renal diseases in human medicine. However, its application in veterinary medicine is in its nascent stage. It was hypothesized that establishing pSWE reference values in nonazotemic dogs would prove valuable in differentiating renal diseases. In light of this, a single-center, quantitative study with an objective to normalize B-mode ultrasound parameters and pSWE values of the kidney in nonazotemic dogs was conducted. A total of 198 animals presented with clinical signs of anorexia, vomiting, weight loss, and dehydration were enrolled in the study spanning 2 years. Among them, 52 nonazotemic dogs were included as subjects for the study. B-mode ultrasound quantitative parameters, including length (L), breadth (B), height (H), cortical thickness (RCT), and medulla thickness (RMT) of the kidneys, as well as the diameter of the aorta (Ao), were normalized. Additionally, calculated parameters such as L:Ao, B:Ao, H:Ao, RCT:Ao, and corticomedullary ratios were worked out. Point shear wave elastography values were obtained from the cranial and caudal poles of renal cortices using ElastPQ stiffness software. The pSWE values of kidneys in nonazotemic dogs were normalized. The mean ± standard error values were 1.04 ± 0.08 m/s (95% confidence interval: 0.88-1.19 m/s) and 4.18 ± 0.62 kPa (95% confidence interval: 2.93-5.42 kPa). In conclusion, B-mode ultrasound quantitative parameters, ratios, and pSWE values were normalized in nonazotemic dogs, which may prove valuable in differentiating renal pathologies in canine patients., (© 2024 American College of Veterinary Radiology.)

Background: Glomerular lesions reflect the onset and progression of renal disease. Pathological diagnoses are widely regarded as the definitive method for recognizing these lesions, as the deviations in histopathological structures closely correlate with impairments in renal function., Methods: Deep learning plays a crucial role in streamlining the laborious, challenging, and subjective task of recognizing glomerular lesions by pathologists. However, the current methods treat pathology images as data in regular Euclidean space, limiting their ability to efficiently represent the complex local features and global connections. In response to this challenge, this paper proposes a graph neural network (GNN) that utilizes global attention pooling (GAP) to more effectively extract high-level semantic features from glomerular images. The model incorporates Bayesian collaborative learning (BCL), enhancing node feature fine-tuning and fusion during training. In addition, this paper adds a soft classification head to mitigate the semantic ambiguity associated with a purely hard classification., Results: This paper conducted extensive experiments on four glomerular datasets, comprising a total of 491 whole slide images (WSIs) and 9030 images. The results demonstrate that the proposed model achieves impressive F1 scores of 81.37%, 90.12%, 87.72%, and 98.68% on four private datasets for glomerular lesion recognition. These scores surpass the performance of the other models used for comparison. Furthermore, this paper employed a publicly available BReAst Carcinoma Subtyping (BRACS) dataset with an 85.61% F1 score to further prove the superiority of the proposed model., Conclusion: The proposed model not only facilitates precise recognition of glomerular lesions but also serves as a potent tool for diagnosing kidney diseases effectively. Furthermore, the framework and training methodology of the GNN can be adeptly applied to address various pathology image classification challenges., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Renal lymphangiectasia (RL) is a rare condition in which lymphatic vessels are dilated giving rise to cyst formation in peripelvic, perirenal and intrarenal locations. Knowledge about RL is limited and based upon individual case reports. This can be genetic or acquired. There is no significant association with any gender or age. It can be manifested as focal or diffuse forms and can be unilateral or bilateral. Most of the cases present with abdominal or flank pain. The diagnosis is based on radiological imaging. Due to rarity of diseases, it has potential to be misdiagnosed as other cystic disease of kidneys. The treatment is mainly conservative but prolonged follow up for associated complications like hypertension and renal vein thrombosis is required. We have presented a case of bilateral renal lymphangiectasia with the review of available literature., (Copyright: © Saudi Medical Journal.)

Iron oxide nanoprobes exhibit substantial potential in magnetic resonance imaging (MRI) of kidney diseases and can eliminate the nephrotoxicity of gadolinium-based contrast agents (GBCAs). Nevertheless, there is an extreme shortage of highly sensitive and renal clearable iron oxide nanoprobes suitable for early kidney damage detection through MRI. Herein, a renal clearable ultra-small ferrite nanoprobe (UMFNPs@ZDS) is proposed for highly sensitive early diagnosis of kidney damage via structural and functional MRI in vivo for the first time. The nanoprobe comprises a ferrite core coated with a zwitterionic layer, and possesses a high T 1 relaxivity (12.52 mm -1 s -1 ), a small hydrodynamic size (6.43 nm), remarkable water solubility, excellent biocompatibility, and impressive renal clearable ability. In a rat model of unilateral ureteral obstruction (UUO), the nanoprobe-based MRI can not only accurately visualize the locations of renal injury, but also provide comprehensive functional data including peak value, peak time, relative renal function (RRF), and clearance percentage via MRI. The findings prove the immense potential of ferrite nanoprobes as a superior alternative to GBCAs for the early diagnosis of kidney damage., (© 2024 Wiley‐VCH GmbH.)

Background: Computed tomography cardiac angiography (CTCA) is recommended for the evaluation of patients with prior coronary artery bypass graft (CABG) surgery. The BYPASS-CTCA study demonstrated that CTCA prior to invasive coronary angiography (ICA) in CABG patients leads to significant reductions in procedure time and contrast-induced nephropathy (CIN), alongside improved patient satisfaction. However, whether CTCA information was used to facilitate selective graft cannulation at ICA was not protocol mandated. In this post-hoc analysis we investigated the influence of CTCA facilitated selective graft assessment on angiographic parameters and study endpoints., Methods: BYPASS-CTCA was a randomized controlled trial in which patients with previous CABG referred for ICA were randomized to undergo CTCA prior to ICA, or ICA alone. In this post-hoc analysis we assessed the impact of selective ICA (grafts not invasively cannulated based on the CTCA result) following CTCA versus non-selective ICA (imaging all grafts irrespective of CTCA findings). The primary endpoints were ICA procedural duration, incidence of CIN, and patient satisfaction post-ICA. Secondary endpoints included the incidence of procedural complications and 1-year major adverse cardiac events., Results: In the CTCA cohort (n ​= ​343), 214 (62.4%) patients had selective coronary angiography performed, whereas 129 (37.6%) patients had non-selective ICA. Procedure times were significantly reduced in the selective CTCA ​+ ​ICA group compared to the non-selective CTCA ​+ ​ICA group (-5.82min, 95% CI -7.99 to -3.65, p ​< ​0.001) along with reduction of CIN (1.5% vs 5.8%, OR 0.26, 95% CI 0.10 to 0.98). No difference was seen in patient satisfaction with the ICA, however procedural complications (0.9% vs 4.7%, OR 0.21, 95% CI 0.09-0.87) and 1-year major adverse cardiac events (13.1% vs 20.9%, HR 0.55, 95% CI 0.32-0.96) were significantly lower in the selective group., Conclusions: In patients with prior CABG, CTCA guided selective angiographic assessment of bypass grafts is associated with improved procedural parameters, lower complication rates and better 12-month outcomes. Taken in addition to the main findings of the BYPASS-CTCA trial, these results suggest a synergistic approach between CTCA and ICA should be considered in this patient group., Registration: ClinicalTrials.gov, NCT03736018., Competing Interests: Declaration of competing interest FP receives institutional research support from Siemens Healthineers. All other authors have reported no conflicts of interest., (Copyright © 2024 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Standard ultrasound (US) finds wide use in renal diseases as a screening procedure, but it is not always able to characterize lesions, especially in differential diagnosis between benign and malignant lesions. In contrast, contrast-enhanced ultrasonography (CEUS) is appropriate in differentiating between solid and cystic lesions as well as between tumors and pseudotumors. We show the case of a nephropathic patient who showed a complex, large, growing renal mass, characterized through a CEUS. This seventy-five-year-old diabetic heart patient showed a 6 cm-complex and plurisected cyst on ultrasound of left kidney. Laboratory data showed the presence of stage IIIb chronic renal failure with GFR 30 ml/min, creatinine 2.33 mg/dl, azotemia 88 mg/dl. The patient performed abdominal CT without contrast medium, showing at the level of the left upper pole, a roundish formation with the dimensions of approximately 70x53x50 mm. At the semiannual checkup, the nephrology examination showed a slight rise in creatinine and, therefore, after six months, it was decided to perform a CT scan without contrast medium again. CT showed a slight increase in the size of the mass located at the left kidney (74x56x57 mm). Given the increased size of the left mass, albeit modest, a CEUS was performed to reach a diriment diagnosis. CEUS concluded for complex cystic formation with presence of intraluminal solid-corpuscular material, with thrombotic-hemorrhagic etiology, in progressive phase of organization, classifiable as Bosniak type II cyst. CEUS in the kidneys is a cost-effective and valuable imaging technique; it is accurate in the characterization of indeterminate lesions and complex cysts., (Copyright by Società Italiana di Nefrologia SIN, Rome,Italy.)

Deep learning algorithms have demonstrated remarkable potential in clinical diagnostics, particularly in the field of medical imaging. In this study, we investigated the application of deep learning models in early detection of fetal kidney anomalies. To provide an enhanced interpretation of those models' predictions, we proposed an adapted two-class representation and developed a multi-class model interpretation approach for problems with more than two labels and variable hierarchical grouping of labels. Additionally, we employed the explainable AI (XAI) visualization tools Grad-CAM and HiResCAM, to gain insights into model predictions and identify reasons for misclassifications. The study dataset consisted of 969 ultrasound images from unique patients; 646 control images and 323 cases of kidney anomalies, including 259 cases of unilateral urinary tract dilation and 64 cases of unilateral multicystic dysplastic kidney. The best performing model achieved a cross-validated area under the ROC curve of 91.28% ± 0.52%, with an overall accuracy of 84.03% ± 0.76%, sensitivity of 77.39% ± 1.99%, and specificity of 87.35% ± 1.28%. Our findings emphasize the potential of deep learning models in predicting kidney anomalies from limited prenatal ultrasound imagery. The proposed adaptations in model representation and interpretation represent a novel solution to multi-class prediction problems., (© 2024. The Author(s).)

Purpose: Renal congestion is a therapeutic target in congestive heart failure. However, its detailed evaluation in a clinical setting is challenging. This study sought to assess renal congestion impairment using superb microvascular imaging (SMI), a simple and accessible method., Methods: Dahl salt-sensitive rats, used as a model for congestive heart failure, underwent central venous pressure (CVP) measurements. Renal congestion was evaluated through measurements of renal medullary pressure (RMP) and assessment of renal perfusion using contrast-enhanced ultrasonography at both the early (control group) and heart failure phases (HF group). All rats were assessed with SMI. The region of interest (ROI) was set in interlobular vessels, interlobar vessels, and a combination of these areas. The area ratio was calculated from the color pixel count in the ROI divided by the total pixel count in the ROI. Intrarenal perfusion index (IRPI) was defined as (maximum area ratio-minimum area ratio) / maximum area ratio., Results: There were no significant differences in renal function and left ventricular ejection fraction between the two groups. CVP, time-to-peak (TTP) in the medulla, and RMP were higher in the HF group than in the control group. In the HF group, IRPI, evaluated in the interlobular vessels, was significantly higher than in the control group. IRPI was positively correlated with TTP in the medulla (p = 0.028, R = 0.60) and RMP (p < 0.001, R = 0.84), indicating that IRPI reflected renal congestion., Conclusions: IRPI is a useful tool for assessing renal congestion in rats with congestive heart failure., (© 2024. The Author(s), under exclusive licence to The Japan Society of Ultrasonics in Medicine.)

Kidney disease is currently prevalent worldwide but only shows insidious symptoms in the early stages. The second near-infrared window (NIR-II) fluorescence imaging has become a widely used preclinical technology for evaluating renal dysfunction due to its high resolution and sensitivity. However, bright renal clearable NIR-II fluorescence nanoprobes with a simple synthesis process are still lacking. Herein, we develop a lactoglobulin (LG)@dye nanoprobe for NIR-II fluorescence imaging of kidney dysfunction in vivo based on a purification-free method. The nanoprobe was synthesized by simply mixing LG and IR820 in aqueous solutions at 70 °C for 2 h based on the covalent interaction between the meso-Cl in IR820 and LG. The synthesized LG@IR820 nanoprobe has bright and stable NIR-II fluorescence, ultra-small size (<5 nm), low toxicity, and renal-clearable ability. The high reaction efficiency and pure aqueous reaction media make the synthesis method purification-free. In a unilateral ureteral obstruction mouse model, incipient renal dysfunction assessment was achieved by LG@IR820 nanoprobe, which couldn't be diagnosed with conventional kidney function indicators. This study provides a bright and purification-free NIR-II LG@IR820 nanoprobe to visualize kidney dysfunction at the early stage., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Page kidney is a rare condition in which an external compression of the kidney as a result of a hematoma or mass causes renal ischemia and hypertension. In a patient with flank pain, elevated blood pressure, and recent trauma, this condition should be considered. Since this condition was first described in 1939, more than 100 case reports have surfaced., Case Report: We describe the case of a 26-year-old man who presented to the Emergency Department with flank pain, vomiting, and elevated blood pressure. A computed tomography scan of the abdomen and pelvis confirmed the presence of a perinephric hematoma, and the interventional radiology team was consulted to resolve the Page kidney. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Symptoms seen in Page kidney may be similar to other more common diagnoses encountered in the emergency department. It is important to maintain a high suspicion and order imaging studies as needed, especially in the setting of trauma, or a recent procedure in the vicinity of the renal parenchyma., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Competing Interests: Declaration of interests We declare no competing interests.

Renal perfusion reflects overall function of a kidney. As an important indicator of kidney diseases, renal perfusion can be noninvasively measured by multiple methods of MR imaging, such as dynamic contrast-enhanced MR imaging, intravoxel incoherent motion analysis, and arterial spin labeling method. In this article we introduce the principle of the methods, review their recent technical improvements, and then focus on summarizing recent applications of the methods in assessing various renal diseases. By this review, we demonstrate the capability and clinical potential of the imaging methods, with the hope of accelerating their adoption to clinical practice., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2023 Elsevier Inc. All rights reserved.)