3D ultrasonic medical imaging based on segmented annular arrays

Abstract

Conventional 2D ultrasonic arrays are formed by square elements, which have a limit of λ/2 spacing. In this paper we present two apertures, which are based on segmented annular (SA) arrays that have the property of producing lower grating lobes and, consequently, that allow increasing the size of the elements. With the purpose of designing apertures of medium size (D=30λ) with a reduced number of active elements (<250), several thinned squared and segmented-annular arrays are here analyzed. A thinning technique valid for SA arrays that is a modified version of the vernier sparse method ("single vernier") is presented. The paper shows that SA arrays may produce images with similar properties than squared arrays, but with a signal intensity around 20 dB above.