[Value of calculation of the kappa coefficient in the evaluation of an imaging method]

Radiologists are often confronted to the choice of the most appropriate statistic tool for evaluating diagnostic imaging methods. Using a radiological literature example, the Kappa agreement test is herein described and its applications are determined. Although widely performed to determine the inter-rater agreement, this test is also suited for the confrontation of two or more diagnostic imaging methods applied on the same subjects and providing categorical data. It procures the degree of agreement between the different methods.