A concave annular array design, based on phasor summation--Part II: Beam profiles and resultant images by B-scan and synthetic focus methods.

Abstract

A brief review of the synthetic focusing method is given. The theoretical limit of resolution that may be achieved with the synthetic focusing methods is demonstrated using experimental results on a thin thread obtained with an annular array whose design was given in Part I. The advantage of large aperture arrays is illustrated by an in vitro reflection image of a dog artery, made with this array, that has at least four times the spatial resolution of present clinical B-scanners operating in the same frequency range.