PERFORMANCE TESTING OF TRANSRECTAL US SCANNERS

PURPOSE: To test the performance of transrectal ultrasound (US) scanne rs in the detection of low-contrast focal lesions as a function of dep th, size, and contrast. MATERIALS AND METHODS: US images of two phanto ms were analyzed by three observers. One phantom was most suitable for US units allowing scanning in the transverse or longitudinal planes, while the other was suitable for any scanning situation. Both phantoms were made of tissue-mimicking material and had six sections. Five sec tions contained different sizes of low-contrast simulated lesions, whi ch were of different echogenicities and were randomly distributed to a depth of 8 cm. The sixth section contained only background material a nd served as a reference. A resolution zone, corresponding to the dept h range over which a given type of lesion was detectable, was determin ed for each of the five lesion-containing sections and a figure of mer it equal to a weighted sum of resolution zone lengths computed. RESULT S: Data from 12 different scanner configurations were analyzed; a broa d range of figures of merit were found. Agreement was found among the three observers regarding relative performance of the scanner configur ations. CONCLUSION: The phantoms are useful for comparing performances of different transrectal US configurations.