PROCEEDINGS ARTICLE | March 20, 2014
Proc. SPIE. 9040, Medical Imaging 2014: Ultrasonic Imaging and Tomography
KEYWORDS: Apodization, Tissues, Ultrasonics, Wave propagation, Transducers, Optical simulations, Beam shaping, Elastography, Chemical elements, Acoustics
A shear wave generation technique which exploits multiple plane waves facing with each other toward their center line is
introduced. On this line, ultrasonic waves interfere constructively resulting two planar shear waves that propagate to the
opposite directions parallel to the transducer instead of oblique wave from multiple point focused pushes due to the
temporal inconsistency of the pushes. One advantage of the plane wave facing technique over an unfocused push beam is
that it generates much larger shear waves because it actively takes advantage of constructive interference between waves
and, moreover, a larger number of elements can be used without diffusing the beam pattern. Field II simulated intensity
maps of the push beams using the proposed method are presented with those of multiple point focusing and unfocusing
techniques for comparison. In the simulation, two plane waves are considered for the simplicity, and the number of
elements, apodization, and steering angles for facing are varied as parameters. Also, elasticity images of CIRS 049A
phantom are presented using the proposed technique with comb-shaped push beams, i.e. multiple push beams are used
simultaneously at different locations. L7-4 transducer is used for the simulation and elasticity imaging.
