The situation is even more difficult for analog systems since adequate focusing precision becomes more difficult as the frequency increases. Moreover, as the imaging frequencies increase, transducer design and fabrication become increasingly difficult. Advanced Technology Recent advances in GE Ultrasound's electronics and transducer technologies have enabled an extension of the imaging envelope well above the conventional 5 - 10 MHz range. This opens the possibility of spatial resolution as fine as 70 microns. Long ignored as important imaging characteristics, probe and system bandwidth are becoming increasingly important to high resolution imaging.
Spatial resolution improves in direct proportion to bandwidth, as well as frequency.
Figure 2 graphically demonstrates the key parameters. The broad band transducers have a significant advantage over the narrow band transducers in that they provide significantly better spatial resolution. Using new materials and assembly methods, one can produce transducers that extend the broad band concept by significantly increasing the imaging frequency. The imaging improvement is illustrated in figures 3 and 4. 3 and 4 illustrate the advantage of high frequency broad bandwidth imaging.