Aspects of the design of performance measuring test objects.

In order for medical ultrasonics to achieve a high and universal standard of systematic and scientific implementation, methods for assessing the imaging performance of scanners must be developed which are both rigorous and simple to use. The difficulty that has been found in this task comes from the complex interaction of the performance parameters. Measurements of parameters should not be presented in mutual isolation. Further, the performance of a scanner, as measured using electronically generated external stimuli, might not be generalised to realistic acoustic situations. If the assessment is to be relevant to the clinical situation these factors must be taken into account. Test objects employing tissue mimicking materials provide the simplest, and possibly the only way to achieving this. In this paper the authors' designs for such test objects together with an indication of a comprehensive test system are presented.