Index of resistivity of renal vessel

BACKGROUND: Renal Resistive Index (RRI) is an important and non-invasive parameter of renal damage and it is associated with abnormal microcirculation or to a parenchymal injury. The aim of our study was to compare the RRI in a cohort of patients with renal diseases categorized in three groups: nephrotic syndrome (NS), acute nephritic syndrome (ANS) and patients with urinary abnormalities (UA). METHODS: Four hundred eighty-two patients with median age of 48 years (IQR 34-62) with indications for kidney disease were included in the study...

Chronic elevation in the systolic blood pressure (SBP) adversely affects the lifespan in the dog by causing injury to the eye, heart, kidney and brain. Understanding the association between SBP and target organ damage (TOD) helps in risk categorization and treatment planning. Therefore, a prospective study was undertaken to find the association between SBP and renal resistive index (RI) in naturally occurring cases of canine systemic hypertension. Based on the ACVIM guidelines 2018, dogs (n=135) were categorized into four risk groups of SBP, viz...

Age-related decline in functional elastin is associated with increased arterial stiffness, a known risk factor for developing cardiovascular disease. While the contribution of elastin insufficiency to the stiffening of conduit arteries is well described, little is known about the impact on the structure and function of the resistance vasculature, which contributes to total peripheral resistance and the regulation of organ perfusion. In this study, we determined how elastin insufficiency impinges on age-related changes in the structure and biomechanical properties of the renal microvasculature, altering renal hemodynamics and the response of the renal vascular bed to changes in renal perfusion pressure (RPP) in female mice...

AIM: Prediabetic patients have generalized microvascular dysfunction, which leads to end-organ damage, just like diabetes. Therefore, prediabetes is not just a mild elevation in blood sugar, and early detection and prevention of possible complications should be the main goal. Color Doppler imaging (CDI) provides morphologic and vascular information on various diseases. The Resistive Index (RI) is a widely used measure of resistance to arterial flow and is calculated from the CDI. CDI evaluation of vessels in the retrobulbar region may be the first sign of micro- and macrovascular complications...

(I) Introduction: The use of Doppler ultrasound allows us to indirectly assess the effect of increased intrarenal pressure on renal blood flow during retrograde intrarenal surgery (RIRS). On the basis of vascular flow spectra from selected blood vessels in the kidney, it is possible to determine Doppler parameters that reflect the renal perfusion status, which indirectly shows the degree of vasoconstriction and reflects the resistance of kidney tissue. (II) Materials and methods: A total of 56 patients were included in the study...

Introduction Chronic kidney disease (CKD) is universally considered a public health burden and the majority of cases are found to be diabetic at the time of diagnosis. Renal biopsy is the prime modality for the complete evaluation of renal injuries but is invasive. Duplex Doppler sonography can help to determine renal resistive index (RRI), which is an excellent marker for demonstrating dynamic or structural changes of intrarenal vessels. In this study, we evaluated the intrarenal hemodynamic abnormalities with RRI in diabetic and non-diabetic kidney disease patients...

PURPOSE: The present study comparatively evaluates the performance of conventional Doppler ultrasound and superb microvascular imaging (SMI) in delineating the cortical microvessels of the transplanted kidney and compares the chronic allograft damage index (CADI) based on the examination of biopsy specimens with Doppler ultrasound and SMI findings. METHODS: Sixty-eight renal transplant recipients underwent kidney biopsy with the pre-diagnosis of rejection before undergoing renal Doppler ultrasound examination between January 2020 and October 2020...

Kidney transplantation (KTx) is the preferred form of renal replacement therapy in chronic kidney disease (CKD) patients, owing to increased quality of life and reduced mortality when compared to chronic dialysis. Risk of cardiovascular disease is reduced after KTx; however, it is still a leading cause of death in this patient population. Thus, we aimed to investigate whether functional properties of the vasculature differed two years post-KTx (postKTx) compared to baseline (time of KTx). Using the EndoPAT device in 27 CKD patients undergoing living-donor KTx, we found that vessel stiffness significantly improved while endothelial function worsened postKTx vs...

 Iodinated contrast media (ICM) are widely used for diagnostic and interventional procedures in radiology and cardiology. Ideally, they should not interact with blood cells or vascular wall cells to avoid deteriorations of the blood circulation. However, it is well known that ICM can affect erythrocytes as well as endothelial cells which consequently might perturb especially the microcirculation. In former studies the influence of two ICM (iodixanol versus iopromide) on the vascular system, the development of blood stasis, on changes in renal resistive index (RRI) and vascular diameters, and on the post-mortem distribution of iodine as marker for ICM in the explanted kidneys was examined...

Renal impairment is concurrent with adverse outcomes such as heart disease in humans and dogs. Intrarenal Doppler ultrasonography (IRD) is used to assess intrarenal hemodynamics, and resistance index (RI) and venous impedance index (VII) are used to evaluate intrarenal hemodynamics in humans with heart failure. However, only a few studies have assessed the efficacy of IRD, especially VII, in dogs, and the methods differ between studies. Additionally, repeatability, reproducibility, and factors influencing IRD values have not been validated in dogs...

BACKGROUND: Reduced renal perfusion has been implicated in the development of septic AKI. However, the relative contributions of macro- and microcirculatory blood flow and the extent to which impaired perfusion is an intrinsic renal phenomenon or part of a wider systemic shock state remains unclear. METHODS: Single-centre prospective longitudinal observational study was carried out. Assessments were made at Day 0, 1, 2 and 4 after ICU admission of renal cortical perfusion in 50 patients with septic shock and ten healthy volunteers using contrast-enhanced ultrasound (CEUS)...

Cryoglobulins are circulating immune complexes that precipitate at cool temperatures and can induce a small-vessel vasculitis. While patients with endocarditis are well known to have circulating cryoglobulins, cryoglobulinemic vasculitis is a rare complication of infective endocarditis with infrequent publication of reported cases. We present two cases of methicillin-resistant Staphylococcus aureus tricuspid valve infective endocarditis in patients with substance use disorder complicated by cryoglobulinemic cutaneous vasculitis confirmed by skin biopsy, including one patient who developed renal and colonic manifestations of vasculitis...

BACKGROUND: Renal resistive index (RRI) measured by Doppler sonography is a marker of microvascular status and it is associated with changes in renal function. Aim of the study was to assess RRI in biopsy-proven tubulointerstitial nephritis (TIN) in patients with and without glomerular disease. METHODS: 132 consecutive patients underwent to native renal biopsy with diagnosis of isolated TIN or in association with glomerulonephritis. Estimated glomerular filtration rate (eGFR), 24-hour urinary protein excretion and renal ecocolorDoppler ultrasonography with RRI assessment were performed at time of enrollment...

Doppler ultrasonography is used in the evaluation of hemodynamics, and the resistivity (RI) and pulsatility (PI) indexes provide information about resistance to blood flow within a vessel. This systematic review was carried out to evaluate renal RI and PI in clinically healthy and nonsedated cats and as well as their usefulness in the evaluation of kidney disease in cats. An electronic search in the PubMed, Scopus, and Web of Science databases was carried out using the terms "resistive index" or "resistivity index" or "pulsatility index;" "Doppler;" "renal" or "kidney;" and "cat" or "feline" in titles, abstracts, and keywords...

Renal allograft thrombosis is not a rare complication of kidney transplant and usually occurs in the early period after transplant, but it can also occur later after transplant. Several factors are associated with this infamous complication. The cause of venous anastomosis thrombosis is most often inflection or twisting of the renal vein, anastomosis stenosis, hypotension, hypercoagulation, or acute rejection of the graft. Doppler ultrasonography can allow identification of signs of thrombosis in the graft vein...

BACKGROUND: The objective is to investigate whether calculating the PPI (Pulse Pressure Index) and the RRI (Renal Resistive Index) using routinely collected Duplex ultrasound waveforms data obtained from the aorta and renal artery correlates and predicts renal function, and determine whether RRI is affected by the presence of a renal artery stenosis. METHODS: The records of 965 patients were evaluated. The RRI or pulsatility index of the aorta, renal artery, hilum, cortex, and medulla were measured with concurrent glomerular filtration rate GFR, Cr, PPI, and HR measurements, among which 75 patients had a 24-hour urine measured for CrCl, and 32 patients had aortic pulse pressure index (API) calculated from the central aortic pressure measured with applanation tonometry...

OBJECTIVE: Preeclampsia, characterized by endothelial dysfunction, is associated with maternal and fetal Doppler alterations. This study aimed to evaluate fetal renal artery Doppler indices in pregnancies complicated with preeclampsia and compare them with normotensive pregnancies. DESIGN: This cross-sectional study enrolled 46 pregnancies complicated with preeclampsia between weeks 24 and 37 of gestation as the study group and 48 normotensive pregnancies as the control group...

Introduction: Recent evidence suggests that complement activation is important in the pathogenesis of pauci-immune (PI) vasculitis. This is a retrospective investigation of the frequency of hypocomplementemia at pauci-immune glomerulonephritis (PIGN) diagnosis, in relation to vasculitic manifestations, renal histopathology, and treatment outcomes. Methods: A total of 115 patients with biopsy-proven PIGN were categorized based on their serum complement C3 (sC3). Histopathology evaluation included activity and chronicity indexes...

BACKGROUND AND PURPOSE: Renal dysfunction is known to affect vasculature and lead to systemic arterial stiffness. It also independently increases the risk of cerebral small vessel disease (cSVD) and stroke. We aimed to examine the effect of renal dysfunction on cerebral hemodynamics and the burden of cSVD. METHODS: Of the 412 patients admitted to Seoul National University Hospital, between May 2015 and 2019, with lacunar infarction and no major intracranial arterial stenosis observed on magnetic resonance angiography, we included 283 patients who had undergone a transcranial Doppler (TCD) ultrasound after 72 h of stroke onset...

INTRODUCTION: The phenomenon of "masked hypertension" is a diagnostic challenge for physicians. The renal resistance index is a radiological index that expresses damage to the renal blood vessels. The literature regarding the relationship between the renal resistance index and primary kidney disease (as a cause of hypertension) or kidney disease as a result of hypertension is low and limited. OBJECTIVES: The aim of this study is to examine the reliability of the renal resistive index as a means of detecting masked hypertension...