chapter  7
16 Pages

## 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 ).