Clinical perspective on renal elasticity quantification by acoustic radiation force impulse: Where we are and where we are going

Figure 1 Effects of different source-to-target distance. A: Distance 2 cm, SWV = 3.08 m/s; B: As the distance becomes greater (4.9 cm), the SWV decreases (2.40 m/s). SWV: Shear wave velocity.

Figure 2 Effects of anisotropy. A: Distance 1.7 cm, SWV = 3.55 m/s; B: Distance 2.2 cm, SWV = 2.32 m/s. The SWV difference between the two measurements is greater than what is expected considering only the source-to-target distance. This is an effect of renal anisotropy and a consequence of an incorrect orientation of the ROI. SWV: Shear wave velocity; ROI: Region of interest.