Figure 8. Bar graph shows mean sensitivities for the three readers individually, paired in double readings, and paired with the CAD system, assuming 100% acceptance of TP CAD detections by the radiologists. Four CAD thresholds were tested and are indexed according to the mean number of FP detections that readers would need to assess and exclude. Only nodules identified with a reader confidence level of 3-5 were included in this analysis. The error bars indicate the low-high range of the values. This diagram illustrates that when CAD operates at a threshold that results in only three FP detections per patient, significantly better performance and reduced interradiologist variability (narrower high-low error bars) were found for radiologists paired with the CAD system, compared with radiologists reading alone or in pairs. Note the small incremental improvement in performance as CAD is allowed to become more sensitive at the expense of a greater number of FP detections.