Factors that Influence Kidney Shear Wave Speed Assessed by Acoustic Radiation Force Impulse Elastography in Patients without Kidney Pathology

Abstract

Our aim was to assess kidney shear wave speed by means of acoustic radiation force impulse (ARFI) elastography in patients without kidney pathology ("normal" patients) and to identify the factors that influence it. We analyzed 91 "normal" patients in whom kidney shear wave speed was assessed by means of ARFI elastography. Five valid ARFI elastographic measurements were obtained in all "normal" patients in both kidneys. In univariate analysis, age (r = -0.370, p = 0.003), gender (female vs. male, r = -0.305, p = 0.003) and measurement depth (r = -0.285, p = 0.01) were significantly correlated with kidney shear wave speed values assessed by ARFI elastography, whereas body mass index, kidney length and renal parenchyma thickness were not correlated. In multivariate analysis, only age (p = 0.006) and gender (p = 0.03) were significantly correlated with kidney shear wave speed values. In conclusion, kidney shear wave speed values assessed by ARFI elastography in "normal" patients are influenced mainly by age and gender and less by measurement depth.

Point shear wave elastography (pSWE) using Acoustic Radiation Force Impulse (ARFI) imaging: a feasibility study and norm values for renal parenchymal stiffness in healthy children and adolescents

“…With regard to mean SWS values in healthy adult kidneys our results in pediatric patients show lower mean values: Hu et al reported a SWS of 2.81 m/s with a 4C1 ultrasound probe [14], whereas Bota et al found SWS values in adult kidneys with a mean of 2.49 m/s for the right and 2.36 m/s for the left kidney using a 9L4 ultrasound probe [28].…”

Value of ultrasound elastography in the diagnosis of native kidney fibrosis.

“…linear increase of renal tissue elasticity associated with elevated urinary pressure [22,26]. Gender [21,34], race [27], weight or body mass index (BMI) [20], and also age [23,34,46] can modify the results in US elastography and several studies have found significant variations of renal parenchymal elasticity in these parameters [20,21,23,27,34,46].…”

“…In ARFI, the power of the force applied on the transducer by the operator [18,41,42], the distance from source to target [21,27,34,42] -in current imaging methods is important as is the maximal depth is 8 cm [8], and also the frequency of the probe [42,43], all of these being potential modifiers of measured shear wave velocity. Furthermore, placement of the probe on the cortex may be difficult in advanced CKD because of a small cortical parenchyma thickness.…”

Evaluation of Renal Parenchyma Elasticity With Acoustic Radiation Force Impulse Quantification in Nutcracker Syndrome and Comparisons With Grayscale Doppler Sonography and Laboratory Findings

“…Acoustic radiation force impulse (ARFI) is a recently established, noninvasive, inexpensive, safe, and convenient, sonography‐based diagnostic technique for evaluating the elastic properties of tissues . In this modality, instead of outer compression, short‐term (0.03–0.4 msec), high‐powered (2.67 MHz frequency) acoustic repulsive radiation force is applied to the tissue within a region of interest through US transducers . This acoustic force causes small translocations in the tissue (1–10 μm).…”

“…[4][5][6] In this modality, instead of outer compression, short-term (0.03-0.4 msec), high-powered (2.67 MHz frequency) acoustic repulsive radiation force is applied to the tissue within a region of interest through US transducers. 7,8 This acoustic force causes small translocations in the tissue (1-10 lm). On the horizontal plane, these translocations are called "shear wave."…”