Ultrasound pulse optimization for the measurement of the contrast agent responses

Optimization of the ultrasound pulses transmitted by an echographic probe is here considered in order to attain an insonification beam having a quasi-constant pressure profile over a large depth interval. Equalized acoustic pressure values, in fact, allow a correct exploitation of an ultrasound contrast agent injected into the human body and also, consent to measure the nonlinear responses generated by the bubbles that form it. A stochastic method of synthesis (based on simulated annealing) able to produce a desired transmission beam shape acting on the carrier frequencies of the acoustic pulses emitted by the array's transducers, has been developed and assessed. The results obtained in terms of pressure profile and simulated echographic images are reported and discussed.