In vivo demonstration of a real-time simultaneous B-mode/spatial coherence GPU-based beamformer

SLSC imaging is an advanced ultrasound beamforming technique that generates images of the coherence in the backscattered echo and has been shown to suppress image degradation due to clutter. However, the computational demand and the need for access to channel data has made real-time implementation difficult. GPU computing can significantly improve computational throughput, but has been used primarily to accelerate offline image processing. By implementing the SLSC algorithm on 3 GPUs and integrating it with a Verasonics ultrasound scanner, we have realized a real-time simultaneous B-mode and SLSC imaging system. We demonstrate the real-time imaging capabilities on an in vivo liver, gallbladder, and carotid artery and present snapshots of the on-screen display. The SLSC images were found to suppress clutter and showed a more homogeneous texture in tissue when compared to the B-mode images. Computation time and imaging frame rate were highly dependent on the imaging parameters. When imaging the liver, 46 transmit beams with a range of 10 cm were obtained at 6.7 fps for standard imaging and at 2.1 fps for harmonic imaging. A frame rate of 5.9 fps was achieved for carotid artery imaging with 129 transmit beams and a range of 3 cm. By restricting the field of view to 65 transmit beams and a range of 2 cm, a frame rate of 12.5 fps was achieved. Further increases in frame rates can be attained with additional system development and improvements to hardware.