This video shows what are the Shear Waves used in Sonoelastography and MR Elastography Imaging.

1. Our mind usually considers the images ‘wonderful, but still’.
We must change our vision considering images as only a fraction of a movie, like in the Shear Waves.

2. Shear wave propagation in homogeneous isotropic phantom. The 4Z1C/HIFU transducers are located at the
top of the volume. The push is focused at 60 mm in the axial direction and at the center of the volume. The
shear wave displacement amplitude and the corresponding B-mode image in 3 cross-sectional planes are
shown. The coronal plane (shown in red) is orthogonal to the push axis and parallel to the direction of shear
wave propagation. The shear wave travels with the same speed in all directions.

3. SHEAR WAVE PROPAGATION IN THE LIVER

4. US Elastography
MR Elastography
Projection of shear waves
in the healthy liver
driving frequency: 50 Hz
actuator: remote loudspeaker
with rod transducer
sequence: bSSFP-MRE
measure time: 16 images in two
breat holds of 20 seconds
Projection of shear waves
in the cirrothic liver
driving frequency: 50 Hz
actuator: remote loudspeaker
With rod transducer
sequence: bSSFP-MRE
measure time: 16 images in two
breat holds of 20 seconds

5. Brain MRE
(a) Shown is an axial MR magnitude image of the brain showing white matter, gray matter and cerebrospinal fluid.
(b) A single wave image from MRE performed at 60 Hz.
(c) The corresponding elastogram is shown and a good correlation between the magnitude image and the stiffness estimate is evident.
12 Hz
25 Hz
35 Hz
50 Hz
62 Hz