Institute of Information Theories and Applications FOI ITHEA
Abstract:
An effective aperture approach is used as a tool for analysis and parameter optimization of mostly
known ultrasound imaging systems - phased array systems, compounding systems and synthetic aperture
imaging systems. Both characteristics of an imaging system, the effective aperture function and the
corresponding two-way radiation pattern, provide information about two of the most important parameters of
images produced by an ultrasound system - lateral resolution and contrast. Therefore, in the design, optimization
of the effective aperture function leads to optimal choice of such parameters of an imaging systems that influence
on lateral resolution and contrast of images produced by this imaging system. It is shown that the effective
aperture approach can be used for optimization of a sparse synthetic transmit aperture (STA) imaging system. A
new two-stage algorithm is proposed for optimization of both the positions of the transmitted elements and the
weights of the receive elements. The proposed system employs a 64-element array with only four active elements
used during transmit. The numerical results show that Hamming apodization gives the best compromise between
the contrast of images and the lateral resolution.