title: Performance testing of transrectal US scanners.
abstract: OBJECTIVE
  To test the performance of transrectal ultrasound (US) scanners in the detection of low-contrast focal lesions as a function of depth, size, and contrast.
  
  
  METHODS
  US images of two phantoms 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 sections contained different sizes of low-contrast simulated lesions, which were of different echogenicities and were randomly distributed to a depth of 8 cm. The sixth section contained only background material and served as a reference. A resolution zone, corresponding to the depth range over which a given type of lesion was detectable, was determined for each of the five lesion-containing sections and a figure of merit equal to a weighted sum of resolution zone lengths computed.
  
  
  RESULTS
  Data from 12 different scanner configurations were analyzed; a broad range of figures of merit were found. Agreement was found among the three observers regarding relative performance of the scanner configurations.
  
  
  CONCLUSIONS
  The phantoms are useful for comparing performances of different transrectal US configurations.
authors.affiliation: Department of Medical Physics, University of Wisconsin, Madison 53706.
authors.forename: E L
authors.initials: EL
authors.lastname: Madsen
authors.forename: J A
authors.initials: JA
authors.lastname: Zagzebski
authors.forename: I R
authors.initials: IR
authors.lastname: Medina
authors.forename: G R
authors.initials: GR
authors.lastname: Frank
mesh_terms: D005069:Evaluation Studies as Topic; D006801:Humans; D008297:Male; D008961:Models, Structural; D011467:Prostate / Q000000981:diagnostic imaging; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods / Q000592:standards