Evaluation of kidney allograft status using novel ultrasonic technologies

Abstract

Early diagnosis of kidney allograft injury contributes to proper decisions regarding treatment strategy and promotes the long-term survival of both the recipients and the allografts. Although biopsy remains the gold standard, non-invasive methods of kidney allograft evaluation are required for clinical practice. Recently, novel ultrasonic technologies have been applied in the evaluation and diagnosis of kidney allograft status, including tissue elasticity quantification using acoustic radiation force impulse (ARFI) and contrast-enhanced ultrasonography (CEUS). In this review, we discuss current opinions on the application of ARFI and CEUS for evaluating kidney allograft function and their possible influencing factors, advantages and limitations. We also compare these two technologies with other non-invasive diagnostic methods, including nuclear medicine and radiology. While the role of novel non-invasive ultrasonic technologies in the assessment of kidney allografts requires further investigation, the use of such technologies remains highly promising.

Prediction of renal allograft chronic rejection using a model based on contrast‐enhanced ultrasonography

“…Contrast‐enhanced ultrasonography examination is not contraindication for impaired kidney function. Contrast‐enhanced ultrasonography displays microvascular tissue perfusion and allows renal blood flow to be quantified, and this assessment demands no special experience of the investigator . There are two substantial arguments for the application of CEUS in the evaluation of renal allograft function.…”

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

“…Despite major improvements in surgical techniques and immunosuppression therapy, today, long-term allograft survival after kidney transplantation remains a major clinical issue. 1,3 In contrast, some transplant centers monitor changes in serum creatinine values in order to detect CAN, but this occurs late in the course of the disease when significant and irreversible histological changes have already developed, precluding timely interventions in order to prevent further damage to the kidney transplant. 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.…”

“…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. 1,3 In contrast, some transplant centers monitor changes in serum creatinine values in order to detect CAN, but this occurs late in the course of the disease when significant and irreversible histological changes have already developed, precluding timely interventions in order to prevent further damage to the kidney transplant. [1][2][3] Therefore, non-invasive methods for early CAN detection are required.…”

“…1,3 In contrast, some transplant centers monitor changes in serum creatinine values in order to detect CAN, but this occurs late in the course of the disease when significant and irreversible histological changes have already developed, precluding timely interventions in order to prevent further damage to the kidney transplant. [1][2][3] Therefore, non-invasive methods for early CAN detection are required. Ultrasound elastography (UE) methods determine tissue stiffness, and have been extensively evaluated in the context of liver fibrosis in the past two decades.…”

“…As other authors also suggested, the main role of UE methods could be in the long-term observation and evaluation of allograft fibrosis during follow up, possibly selecting patients for timely (re)evaluation with kidney biopsy. [1][2][3]…”