Ultrasonic imaging systems

The authors explain the workings of a modern phase-array imaging system and present examples of the technical advances that have helped make such systems possible. A cardiac imaging system will provide images using transducers from 2.5 to 7.5 MHz, make simultaneous Doppler measurements of blood velocity, including color flow, contain analysis software for making measurements on screen, and support a number of peripherals. Technical advances that have made this possible include the ability to make higher frequency phased-array transducers, new piezoelectric materials, advances in signal processing, and software embedded in the systems. The electronic advances include faster and more dense memories, high-speed but low-power logic, the ability to make gate arrays at reasonable cost, surface-mounted packages and improvements in hard-copy devices and video recording technology