The purpose of this project is to examine the impact of CAD schemes on the diagnostic performance of radiologists, especially the change of false-negative interpretations under a CAD cueing environment. Using an observer performance study, we hope to better understand the impact of CAD schemes on diagnostic performance for detection of subtle abnormalities and to find an optimal approach to use CAD schemes in a screening environment. In this project, seven radiologists participated in the study. Each interpreted 120 subtle mammographic cases in five different reading modes including a non-cued mode and four CAD-cued modes . The study results demonstrated that CAD cueing with high accuracy i.e., 90 sensitivity and 0.5 false-positive per image significantly improved observers performance p0.05 . As accuracy of CAD cueing decreased so did observer performance. Reducing cueing sensitivity and specificity increased false-negative rates in non-cued areas p005 . In conclusion, this study indicates that in a laboratory environment, observer performance in the detection of subtle mammographic abnormalities is significantly affected by the inherent performance of a CAD cueing system.