Receiver Operating Characteristic (ROC) Curve: Practical Review for Radiologists

Sensitivity and specificity, which are defined as the number of true positive decisions/the number of actually positive cases and the number of true negative decisions/the number of actually negative cases, respectively, constitute the basic measures of performance of diagnostic tests (Table When the results of a test fall into one of two obviously defined categories, such as either the presence or absence of a disease, then the test has only one pair of sensitivity and specificity values. However, in many diagnostic situations, making a decision in a binary mode is both difficult and impractical. Image findings may not be obvious or clean-cut. There may be a considerable variation in the diagnostic confidence levels between the radiologists who interpret the findings. As a result, a single pair of sensitivity and specificity values is