Quantitative and noninvasive assessment of chronic liver diseases using two-dimensional shear wave elastography

Figure 1 The principle of two-dimensional shear wave elastography. 2D-SWE is created by ultrasound-generated pulses from an acoustic radiation force that produce plane shear waves, and the propagation of the resulting shear waves can be captured in real time. 2D-SWE: Two-dimensional shear wave elastography.

Figure 2 Example of two-dimensional shear wave elastography of the liver implemented using the Aixplorer US system (SuperSonic Imaging, France), which can be displayed simultaneously with the B-mode image. A 2D-SWE image from a 42-year-old male who had normal liver function with liver biopsy-proven fibrosis at METAVIR stage F0. The rectangular box is the area of view where the shear wave measurements were made and color-coded. The round circle is the ROI where the measurements were obtained. The system provides the mean, Max, Min, SD and Diam of the stiffness measurements within the ROI. For this case, the following measurements were made: Young’s modulus: Mean = 4.8 kPa, Min = 3.3 kPa, Max = 5.8 kPa, SD = 0.4 kPa; shear wave velocity: Mean = 1.3 m/s, Min = 1.1 m/s, Max = 5.8 m/s, SD = 0.1 m/s, Depth = 3.6 cm, and Diam = 15.0 mm. 2D-SWE: Two-dimensional shear wave elastography; Diam: Diameter; Max: Maximum; Min: Minimum; ROI: Region of interest; SD: Standard deviation; US: Ultrasound.

Figure 3 Two-dimensional shear wave elastography (Aixplorer US system, SuperSonic Imaging, France) of the liver in chronic hepatitis B patients with liver biopsy-proven fibrosis at METAVIR stages F1 through F4. A: F1 stage, mean Young’s modulus = 5.1 kPa, mean shear wave velocity = 1.3 m/s; B: F2 stage, mean Young’s modulus = 7.4 kPa, mean shear wave velocity = 1.4 m/s; C: F3 stage, mean Young’s modulus = 8.7 kPa, mean shear wave velocity = 1.7 m/s; D: F4 stage, mean Young’s modulus = 11.4 kPa, mean shear wave velocity = 1.9 m/s. Note the liver stiffness gradually increases, and the color of the sampling frame gradually changes in the initial stages and incrementally increases in the later stages of fibrosis. 2D-SWE: Two-dimensional shear wave elastography; US: Ultrasound.

Figure 4 Two-dimensional shear wave elastography (Aixplorer US system, SuperSonic Imaging, France) images of a 69-year-old male with hepatocellular carcinoma based on the cirrhosis caused by hepatitis B virus. A: The mean Young’s modulus is 161.8 kPa and the mean shear wave velocity is 7.3 m/s, which is obviously higher than the benign lesion; B: The area of the tumor is 13.03 cm². 2D-SWE: Two-dimensional shear wave elastography; HBV: Hepatitis B virus; HCC: Hepatocellular carcinoma; US: Ultrasound.

Figure 5 Analysis of failed measurements. A: A 69-year-old female who had right heart failure and could not hold her breath, causing the failed liver stiffness measurement; B: An image acquired by an inexperienced operator who did not set the standard parameters.