Medical Imaging Techniques: An Illustrative Study
These two inadequacies are overcome in the approach of our general protocol. It specifies a procedure in which real cases and real diagnostic tasks are used and in which, moreover, performance is scored in relation to independent, external evidence. It further specifies a psychophysical method that generates perfor
mance data in the form of the relative (or receiver) operating characteristic (ROC). The ROC analysis provides an index of diagnostic accuracy that is independent of extra-image decision factors and of prior probabilities. It is bor rowed from the general theory of signal detection (2 ), has been applied exten sively in perceptual and cognitive studies in psychology (3, 4), and is now being increasingly applied in other fields (5), particularly in medicine (6 ).