Can Accurate Shear Wave Velocities Be Obtained in Kidneys?

Objectives: There are conflicting results in the literature on the use of shear wave elastography of the kidney parenchyma to determine whether renal stiffness values are related to a disease process. This study was conducted to evaluate the raw data from 3 ultrasound systems and determine whether adequate displacement curves are obtained to accurately estimate shear wave speeds.
Methods: Shear wave elastography was performed on 5 healthy volunteers with 3 ultrasound systems. The raw data were collected and evaluated for the shear wave propagation quality to determine whether accurate estimates of renal shear wave speeds could be determined.
Results: Results from the 3 machines demonstrate that accurate shear wave displacement curves are not obtained with renal elastography on existing systems (as of June 2018). One vendor has recently released software that appears to acquire accurate shear wave displacements.
Conclusions: Elastographic studies performed on the kidney to date are likely to be inaccurate. A new algorithm that appears to acquire accurate shear wave displacements in the kidney has been developed. Additional studies are needed to confirm that the new algorithm provides accurate clinical results. This study demonstrates that although the system provides a shear wave speed, it is important to confirm the accuracy of that number by evaluating the raw data.
(© 2019 by the American Institute of Ultrasound in Medicine.)