Readers
Twelve board-certified breast radiologists who use breast ultrasound in their practices were recruited as readers for the trial. Remuneration for 3.5 days was at the prevailing US rate. Eleven readers were from the USA and one from Great Britain. Eleven had no experience with AWBU. One had reviewed limited AWBUs 8 years earlier during the developmental phase of the technology. No reader had foreknowledge of the positivity rate of the test set.
Each reader had a 4-h tutorial with one author (KK) explaining the AWBU reading station operation. The readers reviewed and discussed approximately 12 AWBUs with known cancers, not part of the test set. They were not in the test set because either palpable findings were present or there were no concurrent mammograms. Nothing concerning the study was discussed, other than the use of the data form (Appendix A) and the number of cases to be reviewed.