Minimal transducer requirements to implement limited diffraction beams in clinical practice

The use of limited diffraction beams has been proposed for ultrasonic imaging in order to improve lateral image resolution over a large depth of view. Typically, annular or 2D phased array transducers have been used to generate these waves in vitro or in silico. As a consequence, this kind of ultrasound beam can currently not be generated using clinically available transducers. In this study, computer simulations were used to investigate the minimal transducer requirements for the generation of a good approximation of a limited diffraction beam. Hereto, the number of rows in a 2D phased array was systematically reduced and its effect on the produced beam was investigated. It was found that transducer technology and the number of channels in current commercial scanners are close to the limit to produce a good approximation of limited diffraction beams. Their introduction for clinical imaging could thus be feasible in the near future.