Ultrasonography of the Kidney: A Pictorial Review

Update on the Application of Ultrasonography in Understanding Autosomal Dominant Polycystic Kidney Disease

With an estimated prevalence of 1 in 1000 individuals globally, autosomal dominant polycystic kidney disease (ADPKD) stands as the most prevalent inherited renal disorder. Ultrasonography (US) is the most widely used imaging modality in the diagnosis and monitoring of ADPKD. This review discusses the role of US in the evaluation of ADPKD, including its diagnostic accuracy, limitations, and recent advances. An overview of the pathophysiology and clinical manifestations of ADPKD has also been provided. Furthermore, the potential of US as a noninvasive tool for the assessment of disease progression and treatment response is examined. Overall, US remains an essential tool for the management of ADPKD, and ongoing research efforts are aimed at improving its diagnostic and prognostic capabilities.

Type 2 diabetes albuminuric and non-albuminuric phenotypes have different morphological and functional ultrasound features of diabetic kidney disease

AIMS

Whether different diabetic kidney disease (DKD) phenotypes recognise differences in morphological and vascular properties of the kidney is still unexplored. We evaluated the potential role of kidney ultrasonography in differentiating DKD phenotypes in subjects with type 2 diabetes.

MATERIALS AND METHODS

This is a cross-sectional, single-centre study. Total (TRV) and parenchymal renal volumes (PRV) were calculated by applying the ellipsoid formula for conventional (2D) ultrasonography and with manual segmentation for 3D ultrasonography, and then adjusted for body surface area (aTRV, aPRV). Renal resistive index (RI) was contextually determined. DKD phenotypes have been defined based on increased urinary albumin-to-creatinine ratio (ACR >30 mg/g) and/or reduced eGFR (<60 ml/min/1.73 m² ). Recruitment was planned to have groups of the same size.

RESULTS

Among 256 subjects, 26.2% had No-DKD, 24.6% increased albuminuria only (Alb⁺ ), 24.2% non-albuminuric DKD (Alb^- DKD), and 25.0% albuminuric DKD (Alb⁺ DKD). Compared to No-DKD, RI was significantly higher in all DKD phenotypes, being the highest in Alb⁺ DKD, and with a significant trend of RI > 0.70 to increase across phenotypes. In comparison with No-DKD, both 2D and 3D volumes were increased in Alb⁺ and significantly reduced in Alb^- DKD as well as in Alb⁺ DKD, with significantly lower volumes in Alb^- DKD as compared to Alb⁺ DKD at the same reduced levels of eGFR. In adjusted regressions, compared to No-DKD, RI was associated with Alb⁺ ; both RI and aPRV3D were associated with Alb⁺ DKD; only aPRV3D with Alb^- DKD. Compared to No-DKD, Receiver Operating Characteristic curve analyses, designed taking into account conventional risk factors, showed that US parameters did not ameliorate the characterisation of Alb⁺ and Alb⁺ DKD, while aPRV3D significantly improved the phenotyping of Alb^- DKD.

CONCLUSIONS

As a novel information, we reported that, in type 2 diabetes, the emerging normoalbuminuric DKD phenotype showed reduced TRVs and PRVs even when compared, at similarly reduced eGFR levels, with Alb⁺ DKD opening. In perspective, these findings suggest a possible role of imaging for better discrimination of DKD phenotypes in clinical practice.

Imaging Techniques in Pharmacological Precision Medicine

Biomedical imaging is a powerful tool for medical diagnostics and personalized medicines. Examples of commonly used imaging modalities include Positron Emission Tomography (PET), Ultrasound (US), Single Photon Emission Computed Tomography (SPECT), and hybrid imaging. By combining these modalities, scientists can gain a comprehensive view and better understand physiology and pathology at the preclinical, clinical, and multiscale levels. This can aid in the accuracy of medical diagnoses and treatment decisions. Moreover, biomedical imaging allows for evaluating the metabolic, functional, and structural details of living tissues. This can be particularly useful for the early diagnosis of diseases such as cancer and for the application of personalized medicines. In the case of hybrid imaging, two or more modalities are combined to produce a high-resolution image with enhanced sensitivity and specificity. This can significantly improve the accuracy of diagnosis and offer more detailed treatment plans. In this book chapter, we showcase how continued advancements in biomedical imaging technology can potentially revolutionize medical diagnostics and personalized medicine.

Predicting Progression of Kidney Injury Based on Elastography Ultrasound and Radiomics Signatures

Background: Shear wave elastography ultrasound (SWE) is an emerging non-invasive candidate for assessing kidney stiffness. However, its prognostic value regarding kidney injury is unclear. Methods: A prospective cohort was created from kidney biopsy patients in our hospital from May 2019 to June 2020. The primary outcome was the initiation of renal replacement therapy or death, while the secondary outcome was eGFR < 60 mL/min/1.73 m2. Ultrasound, biochemical, and biopsy examinations were performed on the same day. Radiomics signatures were extracted from the SWE images. Results: In total, 187 patients were included and followed up for 24.57 ± 5.52 months. The median SWE value of the left kidney cortex (L_C_median) is an independent risk factor for kidney prognosis for stage 3 or over (HR 0.890 (0.796−0.994), p < 0.05). The inclusion of 9 out of 2511 extracted radiomics signatures improved the prognostic performance of the Cox regression models containing the SWE and the traditional index (chi-square test, p < 0.001). The traditional Cox regression model had a c-index of 0.9051 (0.8460−0.9196), which was no worse than the machine learning models, Support Vector Machine (SVM), SurvivalTree, Random survival forest (RSF), Coxboost, and Deepsurv. Conclusions: SWE can predict kidney injury progression with an improved performance by radiomics and Cox regression modeling.

Point‐of‐care renal ultrasound: Are longitudinal views of the kidney alone sufficient to rule out hydronephrosis?

Objective

Point‐of‐care ultrasound for the detection of hydronephrosis is frequently used by emergency physicians. The aim of this study was to assess the accuracy of longitudinal views of the kidney compared with a combination of longitudinal and transverse views of the kidney on emergency physician–performed renal point‐of‐care ultrasound to detect hydronephrosis.

Methods

This was a retrospective case‐control study of patients who received a renal point‐of‐care ultrasound examination performed and interpreted as hydronephrosis in the emergency department (ED). These were then matched with a cohort of kidneys from different patients without hydronephrosis. Longitudinal ultrasound views and transverse ultrasound views were reviewed for the presence of hydronephrosis by ultrasound‐trained emergency physicians. The gold standard of hydronephrosis was an overall interpretation based on the complete ultrasound examination consisting of both transverse and longitudinal views by ultrasound‐trained emergency physicians.

Results

Renal point‐of‐care ultrasound exams from 140 kidneys performed in the ED were enrolled in the study. The sensitivity and specificity of longitudinal ultrasound views compared with a combination of longitudinal and transverse ultrasound views of the kidney as a gold standard were 84.3% (95% confidence interval [CI], 77.2–89.9) and 92.9% (95% CI, 87.3–96.5), the positive predictive value was 92.2% (95% CI, 86.1–96.2), and the negative predictive value was 85.5% (95% CI, 78.9–90.7). The positive and negative likelihood ratios were 11.8 (95% CI, 6.5–21.5) and 0.2 (95% CI, 0.1–0.2), respectively.

Conclusions

Longitudinal views of the kidney on ultrasound showed good sensitivity and specificity to detect the presence of hydronephrosis compared with a combination of longitudinal and transverse ultrasound views of the kidney. However, a combination of longitudinal and transverse ultrasound views may still be warranted in high‐risk patients or in those with inadequate visualization of the upper pole of the kidney.

Prediction of Urinary Tract Infection in Neonates with Unexplained Indirect Hyperbilirubinemia

Background: Neonates with urinary tract infection  (UTI) are susceptible to higher rates of morbidity and mortality, specifically when presented with hyperbilirubinemia. Screening for UTIs in jaundiced neonates is a cost-effective strategy. The aims of this study were to investigate the pattern of UTI (prevalence, etiology, and susceptible antimicrobial agents) in neonates admitted to the NICU with unexplained indirect hyperbilirubinemia, as well as to identify early predictors of UTI in order to reduce the present morbidity and long-term consequences in NICU patients. . Methods: A cross-sectional hospital-based study that included 140 neonates diagnosed with unexplained indirect hyperbilirubinemia in the first 4 weeks of life. A questionnaire was applied to obtain demographic and clinical data. A number of laboratory parameters were assessed with clinical examination. Bacterial growth of 1 × 103 colony-forming units/mL of a single uropathogen was used to identify the existence of UTI. Multivariate analysis was used to identify the predicting factors of UTIs. Results: In the NICU group investigated, 25.7% of subjects had a culture-proved UTI. The most frequently  isolated organism was Escherichia coli. Amikacin was the most common antibiotic that the isolates were susceptible to. In multivariable logistic regression analysis, a positive urine culture was statistically associated with an increase in  WBCs  (OR= 6.90, p= 0.001), pyuria (OR= 5.55, p= 0.001), small for gestational age (OR= 4.07, p= 0.021), prolonged phototherapy duration (OR= 3.50, p= 0.034), and the presence of obstetric complications (OR= 2.92, p= 0.001). Conclusion: UTI is substantially prevalent among neonates admitted to the NICU with unexplained indirect hyperbilirubinemia. The importance of routine UTI screening (urine culture)  as part of the clinical assessment of unexplained hyperbilirubinemia was highlighted in this study, particularly in neonates with leukocytosis, pyuria, small for gestational age, prolonged phototherapy, and those born from mothers with a history of obstetric complications.  

A Hybrid Random Forest Classifier for Chronic Kidney Disease Prediction from 2D Ultrasound Kidney Images

Chronic kidney disease (CKD) is one of the causes of mortality in almost all countries across the globe and the notable thing is its asymptomatic nature in the early stages. This disease is characterized by the gradual loss of kidney function in an individual. Frequently chronic kidney disease is diagnosed based on the Estimated Glomerular Filtration Rate (eGFR) determined from blood and urine tests. In order to reduce the risk factors arising due to chronic kidney disease, it is essential to be diagnosed in the earlier stages itself. This work proposes an automated chronic kidney disease detection based on the textural features of the kidney using a hybrid random forest classifier from 2D ultrasound kidney images. The proposed classifier is compared with the other competing machine learning classifiers through experimenting on a dataset of 150 images and gives a better accuracy of [Formula: see text] with [Formula: see text] of recall and precision, thus proving it to be promising in detecting CKD noninvasively in the early stages.

The “Black Pattern”, a Simplified Ultrasound Approach to Non-Traumatic Abdominal Emergencies

Background: A key issue in abdominal US is the assessment of fluid, which is usually anechoic, thus appearing “black”. Our approach focuses on searching for fluid in non-traumatic patients, providing a new, simplified method for point-of-care US (POCUS). Objective: Fluid assessment is based on a three-step analysis that we can thus summarize. 1. Look for black where it should not be. This means searching for effusions or collections. 2. Check if black is too much. This means evaluating anatomical landmarks where fluid should normally be present but may be abnormally abundant. 3. Look for black that is not clearly black. This means evaluating fluid aspects, whether wholly anechoic or not (suggesting heterogeneous or corpusculated fluid). Discussion: Using this simple method focused on US fluid presence and appearance should help clinicians to make a timely diagnosis. Although our simplified, systematic algorithm of POCUS may identify abnormalities; this usually entails a second-level imaging. An accurate knowledge of the physio–pathological and anatomical ultrasound bases remains essential in applying this algorithm. Conclusion: The black pattern approach in non -traumatic emergencies may be applied to a broad spectrum of abnormalities. It may represent a valuable aid for emergency physicians, especially if inexperienced, involved in a variety of non-traumatic scenarios. It may also be a simple and effective teaching aid for US beginners.

Renal Oncocytoma: The Diagnostic Challenge to Unmask the Double of Renal Cancer

Renal oncocytoma represents the most common type of benign neoplasm that is an increasing concern for urologists, oncologists, and nephrologists due to its difficult differential diagnosis and frequent overtreatment. It displays a variable neoplastic parenchymal and stromal architecture, and the defining cellular element is a large polygonal, granular, eosinophilic, mitochondria-rich cell known as an oncocyte. The real challenge in the oncocytoma treatment algorithm is related to the misdiagnosis due to its resemblance, at an initial radiological assessment, to malignant renal cancers with a completely different prognosis and medical treatment. Unfortunately, percutaneous renal biopsy is not frequently performed due to the possible side effects related to the procedure. Therefore, the majority of oncocytoma are diagnosed after the surgical operation via partial or radical nephrectomy. For this reason, new reliable strategies to solve this issue are needed. In our review, we will discuss the clinical implications of renal oncocytoma in daily clinical practice with a particular focus on the medical diagnosis and treatment and on the potential of novel promising molecular biomarkers such as circulating microRNAs to distinguish between a benign and a malignant lesion.

Etiology of Hydronephrosis in adults and children: Ultrasonographic Assessment in 233 patients

Objectives:

Hydronephrosis (HN) is dilatation of the collecting system of the kidney due to obstruction of urine outflow. This study intended firstly, to investigate the efficacy of ultrasound (US) imaging to determine the cause of HN, and secondly, to list the causes of HN.

Methods:

In this retrospective study, 233 patients with HN were scanned to determine the cause of the HN in the period from 1^st January 2016 to 31^st October 2017. Categorical results were written as frequencies and percentages.

Results:

Out of 233, 91.41% were adults and 8.58% were children (P<0.001), 66.10% were male and 33.90% were female (P<0.001). In 55.36%, HN was in the right kidney and 44.64% was in the left (P=0.116). Exactly 58% of patients were suffering from grade-2, 21.5% grade-3, 11.6% grade-1, and 8.2% grade-4 HN. US imaging can determine the cause of HN in 70.4% of patients. Kidney or ureteric calculi were the cause of HN in 54.1% of cases, reflux was in 7.3%, and pelviureteric junction (PUJ) stenosis was in 3.9%.

In cases of calculi induced HN, 25.3% of the calculi were in the vesicoureteric (VUJ) junction, 21.5% were in the renal pelvis, 6.4% were in the PUJ or upper ureter, and only 0.9% were in the middle ureter.

Conclusion:

Ultrasound imaging can determine the cause of HN in more than two thirds of patients. Calculi are the most common cause of HN even in children and are most common in the VUJ junction.

Case Series of Bedside Renal Cell Carcinoma Detected by Point-of-Care Ultrasound in the Ambulatory Setting

Background: Kidney and renal pelvic cancer was the sixth most common cancer in men and 10th most common in women in the United States in 2018. Renal cell carcinoma (RCC), accounts for 86% of malignancies of the kidney. RCC patients are often asymptomatic; up to 25-30% have metastases at diagnosis. Few present with the triad of gross hematuria, flank pain, and abdominal mass. In RCC patients, 36% had 2 symptoms of the triad, and 60% had gross hematuria as 1 symptom. Point-of-care ultrasound (POCUS) offers a way to identify clinically meaningful anatomic abnormalities. This case series presents 3 patients in whom routine POCUS examination performed in an outpatient cardiology clinic found asymptomatic renal masses, resulting in surgical resection and cure of early-stage RCCs. Case Presentation: Patient 1: 54-year-old female with hypertension (HTN). Two solid masses were identified with POCUS in the right kidney. Patient 2: 63-year-old male with coronary artery disease (CAD) and HTN was seen at an 8-month follow-up visit. A 6-cm mass was identified in the left kidney. Patient 3: 69-year-old male with CAD, HTN, and smoking history seen at 5-month follow-up visit. A 3-cm mass in the right kidney was identified. Conclusions: Incorporating POCUS into the routine physical examination in the ambulatory care setting may improve rates of detection and increase the pretest probability of identifying renal pathology with formal imaging studies. With minimal clinician training, earlier and increased detection of asymptomatic RCC may result in improved patient survival.

Exploration of a Framework for the Identification of Chronic Kidney Disease Based on 2D Ultrasound Images: A Survey

BACKGROUND

Chronic kidney disease (CKD) is a fatal disease that ultimately results in kidney failure. The primary threat is the aetiology of CKD. Over the years, researchers have proposed various techniques and methods to detect and diagnose the disease. The conventional method of detecting CKD is the determination of the estimated glomerular filtration rate by measuring creatinine levels in blood or urine. Conventional methods for the detection and classification of CKD are tedious; therefore, several researchers have suggested various alternative methods. Recently, the research community has shown keen interest in developing methods for the early detection of this disease using imaging modalities such as ultrasound, magnetic resonance imaging, and computed tomography.

DISCUSSION

The study aimed to conduct a systematic review of various existing techniques for the detection and classification of different stages of CKD using 2D ultrasound imaging of the kidney. The review was confined to 2D ultrasound images alone, considering the feasibility of implementation even in underdeveloped countries because 2D ultrasound scans are more cost effective than other modalities. The techniques and experimentation in each work were thoroughly studied and discussed in this review.

CONCLUSION

This review displayed the cutting-age research, challenges, and possibilities of further research and development in the detection and classification of CKD.

Classification of Chronic Kidney Disease in Sonography Using the GLCM and Artificial Neural Network

Chronic kidney disease (CKD) can be treated if it is detected early, but as the disease progresses, recovery becomes impossible. Eventually, renal replacement therapy such as transplantation or dialysis is necessary. Ultrasound is a test method with which to diagnose kidney cancer, inflammatory disease, nodular disease, chronic kidney disease, etc. It is used to determine the degree of inflammation using information such as the kidney size and internal echo characteristics. The degree of the progression of chronic kidney disease in the current clinical trial is based on the value of the glomerular filtration rate. However, changes in the degree of inflammation and disease can even be observed with ultrasound. In this study, from a total of 741 images, 251 normal kidney images, 328 mild and moderate CKD images, and 162 severe CKD images were tested. In order to diagnose CKD in clinical practice, three ROIs were set: the cortex of the kidney, the boundary between the cortex and medulla, and the medulla, which are areas examined to obtain information from ultrasound images. Parameters were extracted from each ROI using the GLCM algorithm, which is widely used in ultrasound image analysis. When each parameter was extracted from the three areas, a total of 57 GLCM parameters were extracted. Finally, a total of 58 parameters were used by adding information on the size of the kidney, which is important for the diagnosis of chronic kidney disease. The artificial neural network (ANN) was composed of 58 input parameters, 10 hidden layers, and 3 output layers (normal, mild and moderate CKD, and severe CKD). Using the ANN model, the final classification rate was 95.4%, the epoch needed for training was 38 times, and the misclassification rate was 4.6%.

Pyonephrosis Ultrasound and Computed Tomography Features: A Pictorial Review

Urinary tract infections (UTIs) are the most frequent community-acquired and healthcare-associated bacterial infections. UTIs are heterogeneous and range from rather benign, uncomplicated infections to complicated UTIs (cUTIs), pyelonephritis and severe urosepsis, depending mostly on the host response. Ultrasound and computed tomography represent the imaging processes of choice in the diagnosis and staging of the pathology in emergency settings. The aim of this study is to describe the common ultrasound (US) and computed tomography (CT) features of pyonephrosis. US can make the diagnosis, demonstrating echogenic debris, fluid/fluid levels, and air in the collecting system. Although the diagnosis appears to be easily made with US, CT is necessary in non-diagnostic US examinations to confirm the diagnosis, to demonstrate the cause and moreover to stage the pathology, defining extrarenal complications. In emergency settings, US and CT are differently used in the diagnosis and staging of pyonephrosis.

Ultrasound and Photoacoustic Imaging of the Kidney: Basic Concepts and Protocols

Noninvasive, robust, and reproducible methods to image kidneys are provided by different imaging modalities. A combination of modalities (multimodality) can give better insight into structure and function and to understand the physiology of the kidney. Magnetic resonance imaging can be complemented by a multimodal imaging approach to obtain additional information or include interventional procedures. In the clinic, renal ultrasound has been essential for the diagnosis and management of kidney disease and for the guidance of invasive procedures for a long time. Adapting ultrasound to preclinical requirements and for translational research, the combination with photoacoustic imaging expands the capabilities to obtain anatomical, functional, and molecular information from animal models. This chapter describes the basic concepts of how to image kidneys using different and most appropriate modalities.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.

Point-of-care ultrasound in nephrology

PURPOSE OF REVIEW

The use of POCUS has grown tremendously with the introduction of innovative, easy-to-carry and maneuver hand-held devices. This review focuses on nephrology-centric applications of POCUS that can be incorporated on a daily basis to make impactful and prompt clinical decisions.

RECENT FINDINGS

We review articles covering use of POCUS in the dialysis unit, the Emergency Department, office, and ICU for assessment of volume status, access issues, stones, obstruction, and to help manage patients with AKI, shock, and heart failure.

SUMMARY

POCUS is a welcome addition to our bedside diagnostic armamentarium and has great utility in nephrology. Trials are ongoing in evaluating outcomes with POCUS and physicians' clinical experience using it has been extremely positive.

Gender and side distribution of urinary calculi using ultrasound imaging

Introduction:

Urinary calculi constitute a significant medical problem worldwide. Due to lack of previous studies on gender and side distribution of urinary calculi, the current study was conducted.

Patients and Methods:

This retrospective study involved 590 urinary calculi from the electronic reports of 266 patients. Gender and side distribution were compared using Chi-square test. Relationship between gender and side of urinary calculi was analyzed using cross tabulation test.

Results:

This study involved 590 urinary calculi reported in 266 patients. Among 590 calculi; 565 (95.8%) were in adults, and 25 (4.2%) were in children. Urinary calculi were in male in 397 (67.3%) and in female in 193 (32.7%). Calculi were 304 (51.5%) in right side, and 286 (48.5%) in left side. Exactly 507 (85.9%) of calculi were in the kidneys, and 83 (14.1%) in the ureters. No significant relationship between gender and side of the calculi (P = 0.238), (Odds ratio 0.869, 95% Confidence interval 0.615-1.226).

Conclusion:

Urinary calculi affect male more than female and adults more than children. No significant relationship between calculi and right or left side of the body.

Etiology and impact on outcomes of polycystic kidney disease in abdominal aortic aneurysm

PURPOSE

We investigated the etiology and impact on outcomes of polycystic kidney disease in patients with abdominal aortic aneurysm.

METHODS

Eight-hundred patients who underwent open (n = 603) or endovascular aortic repair (n = 197) were divided into three groups: no cyst (n = 204), non-polycystic kidney (n = 503), and polycystic kidney (≥ 5 cysts in the bilateral kidneys, n = 93). The characteristics and outcomes were compared among the groups.

RESULTS

In the polycystic kidney group, the age was increased and the proportions of patients with male sex, hypertension, and estimated glomerular filtration rate < 30 mL/min/1.73 m² were greater. The overall hospital mortality rates were similar. The incidence of acute kidney injury after elective open aortic repair was increased in the polycystic kidney group (12%, 17%, and 29%, P = 0.020). In the polycystic kidney group, 80 patients did not have renal enlargement or a family history of renal disease, while 13 (corresponding to 1.6% [13/800] of the overall patients), had renal enlargement, suggesting the possibility of hereditary polycystic kidney disease.

CONCLUSIONS

In our cohort, 1.6% of the patients with abdominal aortic aneurysm who underwent surgery were at risk of hereditary polycystic kidney disease. Polycystic kidney disease was associated with acute kidney injury after open aortic repair.

Ultrasonographic measurement of the renal resistive index in the cynomolgus monkey (Macaca fascicularis) under conscious and ketamine-immobilized conditions

Measurement of the renal resistive index (RRI) is one of the standard diagnostic procedures for assessing kidney disability clinically. This method is expected to be used for the same purpose in many kinds of animals, including monkeys utilized in conventional toxicology studies. To establish a practical RRI measurement procedure in cynomolgus monkeys (Macaca fascicularis), RRI was measured by ultrasonography in the spine position in conscious and ketamine-immobilized monkeys. The RRI of conscious monkeys and ketamine-immobilized monkeys could be measured consistently without excessive abdominal or thoracic movement. Consequently, the variability of the RRI in conscious monkeys was comparable to that in ketamine-anesthetized monkeys. No sex difference in RRI was noted between the two conditions. The mean values and SD of the RRI of 48 healthy monkeys (n=24/sex) were 0.55 ± 0.07 and 0.50 ± 0.05, under conscious and ketamine-immobilized conditions, respectively. The RRI of ketamine-immobilized monkeys was significantly lower than that of conscious monkeys, correlating with the decreased blood pressure and heart rate. In a monkey model of cisplatin-induced acute renal injury, which was characterized histopathologically by minimal to mild renal tubular necrosis and regeneration, the RRI was increased beyond the cut off value (mean + 2SD, 0.68) associated with the progression of renal pathogenesis. The present results suggest that ultrasonographic measurement of the RRI in conscious monkeys would be a useful tool in conventional toxicology studies evaluating drug-induced renal injury.

Evaluation of Tryptic Podocin Peptide in Urine Sediment Using LC-MS-MRM Method as a Potential Biomarker of Glomerular Injury in Dogs with Clinical Signs of Renal and Cardiac Disorders

The early asymptomatic stage of glomerular injury is a diagnostic challenge in the course of renal and extra-renal disease, e.g., heart insufficiency. It was found that podocin, a podocyte-specific protein present in the urine, may serve as a biomarker in the diagnosis of glomerular disease in humans and animals including glomerulonephritis, glomerulosclerosis, amyloidosis, or nephropathy. Therefore, there is a need of development of the sensitive and straightforward method of urinary podocin identification. In this work, we report our extended research under the glomerular injury investigation in dogs by application of clinical examination and LC-MS-MRM method in the identification of canine podocin in urine samples. The LC-MS-MRM method is based on the identification of podocin tryptic peptide with the ²¹⁸H-AAEILAATPAAVQLR-OH²³² sequence. The model peptide was characterized by the highest ionization efficiency of all the proposed model podocin tryptic peptides in a canine urine sediment according to the LC-MS/MS analysis. The obtained results revealed the presence of the model peptide in 40.9% of dogs with MMVD (active glomerular injury secondary to heart disease = cardiorenal syndrome-CRS) and 33.3% dogs with chronic kidney disease. The potential applicability of the developed methodology in the analysis of podocin in canine urine sediments was confirmed.

What do we know about volumetric medical image interpretation?: a review of the basic science and medical image perception literatures

Interpretation of volumetric medical images represents a rapidly growing proportion of the workload in radiology. However, relatively little is known about the strategies that best guide search behavior when looking for abnormalities in volumetric images. Although there is extensive literature on two-dimensional medical image perception, it is an open question whether the conclusions drawn from these images can be generalized to volumetric images. Importantly, volumetric images have distinct characteristics (e.g., scrolling through depth, smooth-pursuit eye-movements, motion onset cues, etc.) that should be considered in future research. In this manuscript, we will review the literature on medical image perception and discuss relevant findings from basic science that can be used to generate predictions about expertise in volumetric image interpretation. By better understanding search through volumetric images, we may be able to identify common sources of error, characterize the optimal strategies for searching through depth, or develop new training and assessment techniques for radiology residents.

Point of care renal ultrasonography for the busy nephrologist: A pictorial review

The application of bedside ultrasonography in routine clinical practice has dramatically evolved over the last few decades and will likely continue to grow as technological advances lead to enhanced portability and affordability of the equipment. Despite mounting interest, most nephrology fellowship training programs do not offer formal training in renal ultrasonography and there is inertia among practicing nephrologists to adopt this skill as a practice-changing advancement. Lack of familiarity with the topic is considered a key reason for this inertia. Understanding of basic ultrasound physics, instrumentation, principles of optimal image acquisition and interpretation is critical for enhanced efficiency and patient safety while using this tool. Herein, we provide a brief overview of the basic principles of diagnostic renal ultrasonography as well as introduction to common sonographic pathologies encountered in day-to-day nephrology practice with illustrative images.

Association between grades of Hydronephrosis and detection of urinary stones by ultrasound imaging

Objective:

To correlate between hydronephrosis grades and detection of urinary stones by B-mode ultrasound imaging.

Methods:

This study included 210 ultrasound reports of patients who underwent abdominal ultrasound imaging in the period from 1st January 2016 to 31st October 2017, and diagnosed as hydronephrosis. Data collected from the ultrasound reports. The detection rates of stones using B-mode ultrasound imaging compared in different grades of hydronephrosis. Chi-square test and Odds Ratio (OR) were performed to assess the relationship between variables.

Results:

Of 210 patients, hydronephrosis was unilateral in 91.8% of patients and bilateral in 8.1%. It was distributed in grade 2, grade 3, grade 1 and grade 4 in 58.57%, 20%, 12.38% and 9.1% of the patients respectively. B-mode ultrasound imaging determined the cause of hydronephrosis in 65.2% of cases. Urinary stones were the cause in 60% of the patients. The detection rate of urinary stones was 50%, 61% and 71.4% for grades 1, 2 and 3 hydronephroses respectively. On simple logistic regression analysis, urinary stones detected in Grade-3 were four times more compared to that in grade 4 (P=0.016) (OR 4.125, 95% CI 1.29-13.136%).

Conclusion:

Detection of urinary stones as the cause of hydronephrosis increases with increasing the grade of hydronephrosis from Grade-I to Grade-III and decrease in Grade-IV. Urinary stones were the cause of hydronephrosis in 60% of the patients in this study.

Three-Dimensional Surface Point Cloud Ultrasound for Better Understanding and Transmission of Ultrasound Scan Information

Ultrasound is notoriously plagued by high user dependence. There is a steep drop-off in information in going from what the sonographer sees during image acquisition and what the interpreting radiologist is able to view at the reading station. One countermeasure is probe localization and tracking. Current implementations are too difficult and expensive to use and/or do not provide adequate detail and perspective. The aim of this work was to demonstrate that a protocol combining surface three-dimensional photographic imaging with traditional ultrasound images may be a solution to the problem of probe localization, this approach being termed surface point cloud ultrasound (SPC-US). Ultrasound images were obtained of major vessels in an ultrasound training phantom, while simultaneously obtaining surface point cloud (SPC) 3D photographic images, with additional scanning performed on the right forearm soft tissues, kidneys, chest, and pelvis. The resulting sets of grayscale/color Doppler ultrasound and SPC images are juxtaposed and displayed for interpretation in a manner analogous to current text-based annotation or computer-generated stick figure probe position illustrations. Clearly demonstrated is that SPC-US better communicates information of probe position and orientation. Overall, it is shown that SPC-US provides much richer image representations of probe position on the patients than the current prevailing schemes. SPC-US turns out to be a rather general technique with many anticipated future applications, though only a few sample applications are illustrated in the present work.