Ultrafast imaging using combined transmissions with coherence-based reconstruction

Abstract

Ultrafast plane wave (PW) imaging and synthetic aperture (SA) imaging have become the prevalent techniques for non-conventional medical ultrasound imaging. In both imaging techniques, the image contrast is generally compromised by reducing the number of transmissions for high frame rate. Moreover, the axial ghost artifact in PW imaging has been demonstrated attributed to the edge array elements. We hereby propose a new methodology that achieves high contrast and reduces the axial ghost artifact with only three transmissions for ultrafast imaging. A new coherence-based factor was derived. The raw data from the PW and the spherical wave (SW) transmissions were compounded based on the factor, with the consideration of their respective coherence and interrelationship, to suppress the side lobes and reduce the axial artifact. Field II simulations show that our proposed method greatly reduced the axial artifact by 20 dB ∼ 35 dB compared with coherent plane wave compounding (CPW) and suppressed side lobes by 15 dB ∼ 30 dB compared with CPW and sparse SA imaging.