Rapid simulations of diagnostic ultrasound with multiple-zone receive beamforming

Abstract

Routines are under development in FOCUS, the “Fast Object-oriented C + + Ultrasound Simulator” (http://www.egr.msu.edu/~fultras-web), to accelerate B-mode image simulations by combining the fast nearfield method with time-space decomposition. The most recent addition to the FOCUS simulation model implements receive beamforming in multiple zones. To demonstrate the rapid convergence of these simulations in the nearfield region, simulations of a 192 element linear array with an electronically translated 64 element sub-aperture are evaluated for a transient excitation pulse with a center frequency of 3 MHz. The transducers in this simulated array are 5 mm high and 0.5133 mm wide with a 0.1 mm center to center spacing. The simulation is evaluated for a computer phantom with 100,000 scatterers. The same configuration is simulated in Field II (http://field-ii.dk), and the impulse response approach with a temporal sampling rate of 1 GHz is used as reference. Simulations are evaluated for the entire B-mode image simulated with each approach. The results show that, with sampling frequencies of 15 MHz and higher, FOCUS eliminates all of the numerical artifacts that appear in the nearfield region of the B-mode image, whereas Field II requires much higher temporal sampling frequencies to obtain similar results. [Supported in part by NIH Grant R01 EB012079.]