: Magnetic resonance elastography (MRE) allows noninvasive assessment of tissue stiffness in vivo. Renal arterial stenosis (RAS), a narrowing the renal artery, promotes irreversible fibrosis that threatens kidney viability and may elevate stiffness. However, also be affected by hemodynamic factors. This study tested hypothesis blood flow (RBF) is an important determinant as measured MRE.

Tissue mechanical properties such as elasticity are linked to tissue pathology state. Several groups have proposed shear wave propagation speed quantify properties. It is well known that biological tissues viscoelastic materials; therefore, velocity dispersion resulting from material viscoelasticity expected. A method called shearwave ultrasound vibrometry (SDUV) can be used by measuring of speed. However, there not a gold standard for validation. In this study, we present an independent...

Shearwave dispersion ultrasound vibrometry (SDUV) is used to quantify both tissue shear elasticity and viscosity by evaluating of wave propagation speed over a certain bandwidth (50 500 Hz). The motivation for developing imaging techniques the desire diagnose disease processes. However, it important study mechanical properties healthy tissues; such data can enhance clinical knowledge improve understanding tissue. purpose this evaluate feasibility using SDUV in vitro measurements renal cortex...

<h2>Abstract</h2> Five small porcine aortas were used as a human carotid artery model, and their stiffness was estimated using shear wave elastography (SWE) in the arterial wall stiffened region mimicking stiff plaque. To optimize SWE settings, bandwidth measured with respect to acoustic radiation force push length number of compounded angles for motion detection plane imaging. The mean simulated plaque moduli varied from 41 ± 5 97 10 kPa 86 13 174 35 kPa, respectively, over pressure range...

Elasticity imaging methods have been used to study tissue mechanical properties and demonstrated that elasticity changes with disease state. In current shear wave typically only speed is measured rheological models, e.g. Kelvin-Voigt, Maxwell Standard Linear Solid, are solve for such as the viscoelastic complex modulus. This paper presents a method quantify material in model-independent way by estimating elastic modulus over wide frequency range using time-dependent creep response induced...

Ultrasound radiation force-based methods can quantitatively evaluate tissue viscoelastic material properties. One of the limitations current is neglecting inherent anisotropy nature certain tissues. To explore phenomenon in a laboratory setting, we created two phantom designs incorporating fibrous and fishing line with preferential orientations. Four phantoms were made cube-shaped mold; both arranged multiple layers embedded porcine gelatin using different concentrations (8%, 14%). An...

Microvascular rarefaction distal to renal artery stenosis is linked dysfunction and poor outcomes. Low–energy shockwave therapy stimulates angiogenesis, but the effect on kidney microvasculature unknown. We hypothesized that low–energy would restore microcirculation alleviate in renovascular disease. Normal pigs subjected 3 weeks of were treated with six sessions (biweekly for consecutive weeks) or left untreated. assessed BP, urinary protein, stenotic blood flow, GFR, microvascular...

Currently, dynamic elastography techniques estimate the linear elastic shear modulus of different body tissues. New methods that investigate other properties soft tissues such as anisotropy, viscosity, and nonlinearity would provide more information about structure function tissue might a better contrast than stiffness hence effective diagnostic tools for some diseases. It has previously been shown wave velocity in medium changes due to an applied stress, phenomenon called acoustoelasticity...

Ultrasound shear wave elastography (SWE) is emerging as a promising imaging modality for the noninvasive evaluation of tissue mechanical properties. One ways to explore viscoelasticity through analyzing velocity dispersion curves. To dispersion, it necessary estimate at each frequency. An increase available spectrum be used phase estimation significant analysis in vivo. A number methods suffer because that one can work with limited. We present an alternative method classical 2-D Fourier...

Quantitative ultrasound elastography is increasingly being used in the assessment of chronic liver disease. Many studies have reported ranges shear wave velocity values for healthy individuals and patients with different stages fibrosis. Nonetheless, ongoing efforts exist to stabilize quantitative measurements by assessing factors that influence tissue values, such as food intake, body mass index, scanners, scanning protocols, image quality. Time-to-peak (TTP) methods been routinely measure...

Cationic derivatives of 5,10,15-tris[4-(pyridin-4-ylsulphanyl)-2,3,5,6-tetrafluorophenyl]-corrolategallium(III)pyridine and 5,10,15-tris[4-(pyridin-2-ylsulfanyl)-2,3,5,6-tetrafluorophenyl]-correlategallium(III)pyridine were synthesized their photosensitizing properties against the naturally bioluminescent Gram-negative bacterium Allivibrio fischeri evaluated. The cationic corrole exhibited antibacterial activity at micromolar concentrations this strain.

Renal fibrosis threatens kidney viability and has been associated with altered tissue structure affecting the biomechanical properties of kidney, quantifiable as elasticity viscosity. Importantly, early detection renal may guide therapy eliminate invasive biopsy procedures. The ability to detect monitor it regularly sufficient sensitivity specificity is an active area research. A newly emerging method called shearwave dispersion ultrasound vibrometry (SDUV), that quantifies both viscosity by...

Tissues such as skeletal muscle and kidneys have well-defined structure that affects the measurements of mechanical properties. As an approach to characterize material properties these tissues, different groups assumed they are transversely isotropic (TI) measure shear wave velocity it varies with angle respect structural architecture organ. To refine in organs, is desirable tissue-mimicking phantoms exhibit similar anisotropic characteristics. Some approaches involve embedding fibers into a...

Elasticity is measured by shear wave elasticity imaging (SWEI) methods using acoustic radiation force to create the waves. Phase aberration and tissue attenuation can hamper generation of waves for in vivo applications. In this study, effects phase ultrasound focusing creating were explored. This includes shifts amplitude on characteristics such as amplitude, speed, center frequency, bandwidth. Two samples swine belly used experimentally. To explore individually, experiments complemented...

Ultrasound shear wave elastography is a promising noninvasive, low cost, and clinically viable tool for liver fibrosis staging. Current imaging technologies on clinical ultrasound scanners ignore dispersion use single group velocity measured over the bandwidth to estimate tissue elasticity. The center frequency of waves induced by acoustic radiation force depend push beam (push duration, F-number, etc.) viscoelasticity medium, therefore are different across from vendors. As result, vendors...

Noninvasive measurement of tissue viscoelastic properties is gaining more attention for screening and diagnostic purposes. Recently, measuring dynamic response under a constant force has been studied estimation in terms retardation times. The essential part such test an instrument that capable creating controlled axial suitable clinical applications. Such device should be lightweight, portable, easy to use patient studies capture dynamics external stress. In this paper, we present the design...

Acoustic radiation force-based shear wave elasticity (SWE) methods are used to characterize soft tissue pathologies by quantifying viscoelastic (VE) properties. To adequately evaluate SWE measurements of VE properties, it is important properties mimicking phantoms with an independent method. In this study a phantom was developed and its concentration modified vary the viscosity. Three were studied hyper frequency spectroscopy (HFVS). The quantified fitting Kelvin-Voigt fractional derivative...

Fibrosis has been associated with altered tissue structure affecting the biomechanical properties of organs, quantifiable as elasticity and viscosity. Renal fibrosis threatens kidney viability. Evaluation renal by conventional imaging modalities is difficult. Importantly, early detection may guide therapy eliminate invasive biopsy procedures. A newly emerging method called Shearwave Dispersion Ultrasound Vibrometry (SDUV) offers a potential tool to determine viscosity in vivo. SDUV...

Viscoelastic micellar fluid characteristics have been measured with mechanically generated shear waves and showed good agreement to oscillatory methods. In this paper, in wormlike fluids using ultrasound were successfully detected. Micellar of different concentrations (100, 200, 300, 400 mM) studied ultrasound-based conventional rheology The complex modulus from tests between 0.001 15.91 Hz was characterized an extended Maxwell model. elastic viscous parameters found rheological testing used...

Renal fibrosis threatens kidney viability and has been associated with altered tissue structure affecting the biomechanical properties of kidney, such as elasticity viscosity. Although there are limited studies regarding viscoelastic renal tissue, an in vivo MRE study suggests that shear changes a result hemodynamic variables. A newly emerging method called Shearwave Dispersion Ultrasound Vibrometry (SDUV) offers tool to determine viscosity vivo. SDUV quantifies both by evaluating dispersion...

Ultrasound radiation force-based methods have the ability of estimating tissue viscoelastic material properties. A limitation current exists when estimation mechanical properties is performed under assumption that isotropic and homogeneous thus, neglecting inherent anisotropy nature certain tissues. To study characteristics this phenomenon in a laboratory setting, we created transversely (TI) phantom incorporating fibrous with preferential orientations embedded mimicking gelatin using two...