Using Breast Radiographers’ Reports as a Second Opinion for Radiologists’ Readings of microcalcifications in Digital Mammography Short title Breast Radiographers’ Reports as a Second Opinion

Objective The aim of this study was to investigate a practical method for incorporating radiographers’ reports with radiologists’ readings of digital mammograms. Methods This simulation study was conducted using data from a free-response receiver operating characteristic (FROC) observer study obtained with 75 cases (25 malignant, 25 benign, and 25 normal cases) of digital mammograms. Each of the rating scores obtained by six breast radiographers was utilized as a second opinion for four radiologists’ readings with the radiographers’ reports. A logical “OR” operation with various criteria settings was simulated for deciding an appropriate method to select a radiographer’s report in all combinations of radiologists and radiographers. The average figure of merit (FOM) of the radiologists’ performances was statistically analyzed using a jackknife procedure (JAFROC) to verify the clinical utility of using radiographers’ reports. Results Potential improvement of the average FOM of the radiologists’ performances for identifying malignant microcalcifications could be expected when using radiographers’ reports as a second opinion. When the threshold value of 2.6 in BI-RADS assessment was applied to adopt/reject a radiographer’s report, FOMs of radiologists’ performances were further improved. Conclusion When using breast radiographers’ reports as a second opinion, radiologists’ performances potentially improved when reading digital mammograms. It could be anticipated that radiologists’ performances were improved further by setting a threshold value on the BI-RADS assessment provided by the radiographers. Advances in knowledge For the effective use of a radiographer’s report as a second opinion, radiographer’s rating scores and its criteria setting for adoption/rejection would be necessary.