Breast imaging with a conical transducer/ annular array hybrid scanner

A hybrid conical scanner consisting of a 37.5 degrees, 4 MHz conical receiver and a five element 5 cm dia. 4 MHz annular array transmitter has been developed for breast imaging. The ultrasound fields and imaging characteristics of three interesting geometries are compared. These are: (1) the annular array used in conventional pulse-echo mode, (2) the conical transducer used in combination with the full annular array and (3) the conical …