Renal Elastography for the Assessment of Chronic Kidney Disease

Abstract

For the assessment of chronic kidney disease, point shear wave elastography (pSWE) and shear wave speed imaging (2D-SWE) are suitable, but the use of elastography in the assessment of the kidneys is more difficult compared to the use in other organs, because of the complex architecture of the kidneys, characterized by a high anisotropy and also by the limited size of the renal parenchyma, where the measurements are performed. Despite the difficulties of renal elastography, the reproducibility of the method is good. Kidney shear wave speed values are influenced mainly by age and gender, while in chronic kidney disease, renal stiffness is sometimes decreased in more advanced disease and is not influenced mainly by the progression of fibrosis. There are studies proving that a decreased renal blood flow is associated with a decrease in kidney shear wave speed, the fact that could explain why patients with CKD tend to have lower kidney stiffness. Elastography is a real-time imaging method that could be useful in the assessment of the kidneys, but more extensive studies and even some improvements of the processing algorithms of raw data of elastography machines seem to be needed to implement the use in clinical practice.