Non‐invasive assessment of kidney allograft fibrosis with shear wave elastography: A radiological‐pathological correlation analysis

Abstract

Shear wave elastography can be used as a non-invasive tool to evaluate kidney allograft fibrosis with reasonable interobserver agreement and superior test performance to serum creatinine in detecting early tubulointerstitial fibrosis.

Shear-Wave Elastography Variability Analysis and Relation with Kidney Allograft Dysfunction: A Single-Center Study

“…We conducted this study to examine the intra-and inter-examinations variability of kidney allografts SWE stiffness as an additional tool in post kidney transplantation evaluation. The patients included in our cohort had similar demographic characteristics in terms of age and gender with the patients investigated by Ma et al [23], but are younger as compared to those investigates by Järv et al [37].…”

“…Shear wave elastography is considered potentially suitable elastography method for the assessment of fibrosis in kidney recipients, but no examination protocol or reference value had yet established [37]. A small amount of evidence relating to SWE for kidney transplant evaluation exists in the scientific literature, showing higher parenchymal stiffness in kidney allograft as compared to stable function [22,23], association with fibrosis [19], significantly lower stiffness values in overweight or obese patients [37]. We conducted this study to examine the intra-and inter-examinations variability of kidney allografts SWE stiffness as an additional tool in post kidney transplantation evaluation.…”

“…Ghonge et al evaluated the role of SWE in the differentiation of stable renal allograft from acute allograft dysfunction on a sample of 72 patients (stable function in 30 patients, acute dysfunction in 19 patients and chronic dysfunction in 11 patients) and showed significantly higher parenchymal stiffness on patients with chronic allograft dysfunction (stiffness values in stable function < stiffness values in acute allograft dysfunction < stiffness values in Diagnostics 2020, 10, 41 3 of 17 chronic allograft dysfunction (p-value, p < 0.02) [22]. Ma et al reported a median stiffness at the cortex of 22.3 kPa (IQR = (19.0-26.5) kPa) and at the medulla of 15.0 kPa (IQR = (13.7-18.0) kPa) in patients with kidney allograft tubulointerstitial fibrosis and a significant correlation between semiquantitative Banff ci/ct score and cortical (p-value = 0.004) and medullary (p-value < 0.001) tissue stiffness [23]. Despite the advantages provided by the fast diagnosis and non-invasiveness of the SWE technique, several disadvantages were identified [24]: non-specificity of the SWE values among different grades of kidney allograft fibrosis, high impact of transducer pressure on cortical stiffness, high inter-and intra-observed variation, specific software, and hardware requirements.…”

Editorial Comment to Non‐invasive assessment of kidney allograft fibrosis with shear wave elastography: A radiological‐pathological correlation analysis

“…1 Aside from other histological findings (glomerulopathy, tubular atrophy, vasculopathy), the most prominent histological characteristic of CAN is interstitial fibrosis, which is a strong predictor of kidney allograft failure, and the early appearance of CAN is an independent predictor for poor long-term kidney transplant survival. 6 The authors investigated the relationship between tissue stiffness and histological severity of tubulointerstitial fibrosis in 32 patients. 1,3 However, kidney biopsy has some limitations, such as its invasive nature (with risk of complications) and sampling error, as well as total costs and patient discomfort.…”

“…1 Thus, we rejoice in reading the great experience of Ma et al from Hong Kong that evaluated the use of shear wave elastography (SWE) in the assessment of kidney allograft tubulointerstitial fibrosis, which is a real-time two-dimensional method that allows clinicians to precisely choose the region of interest for stiffness evaluation. 6 The authors investigated the relationship between tissue stiffness and histological severity of tubulointerstitial fibrosis in 32 patients. Interestingly, they showed that the tissue stiffness determined by SWE correlated with the histological severity of interstitial fibrosis and tubular atrophy, with good interobserver agreement.…”