Is the area under an ROC curve a valid measure of the performance of a screening or diagnostic test?
The AUC is an unreliable measure of screening performance because in practice the standard deviation of a screening or diagnostic test in affected and unaffected individuals can differ. The problem is avoided by not using AUC at all, and instead specifying DRs for given FPRs or FPRs for given DRs.
The use of DCE MR imaging tends to increase sensitivity and decrease specificity for all readers, but the differences are not significant.