Image Formation of Multifrequency Vibro-Acoustography: Theory and Computational Simulations

This paper presents an extension of vibro-acoustography imaging technique. The standard technique relies on the single-frequency dynamic radiation force (or stress) produced by a highly focused dual-frequency ultrasound beam. We propose a multifrequency vibro-acoustography method based on the radiation stress generated by a beam with multiple frequencies. The system point-spread function (PSF) is obtained in terms of the acoustic emission by a point-target in response to the employed radiation stress. The PSF is evaluated for an eight- and a sixteen-element sector array transducers. Three phantom images are used to show how the system transforms them into observed data. Considering only visual criteria such as contrast and resolution, simulations show the sixteen-element sector transducer renders better images.