Experimental validation of simultaneous excitation of orthogonal eoded push pulses for fast shear wave elastography

Shear wave elastography is useful for quantitatively evaluating tissue elasticity by measuring the speed of a shear wave induced within the body by acoustic radiation. The purpose of this paper is to demonstrate a pushing-and-imaging sequence, coded push pulse excitation to increase the signal-to-noise ratio (SNR) of the observed shear wave propagation without increasing measurement time and push pulse amplitude. In this paper, we irradiate multiple coded-pulse sequences from different locations at the same time and separate overlapped shear waves by decoding to quickly image a wider area with high SNR. We divided the aperture into two sub-apertures and irradiated coded pulse sequences from each sub-aperture at the same time using Orthogonal Golay Code (OGC). The received shear waves induced by two push pulse sequences are overlapped but are separated orthogonaly after postprocessing. As a result, measurement time decreases and SNR increases due to push pulse compression. The proposed method was validated with an elasticity quality assurance phantom using a linear probe (VeraSonics, L7-4).