Some common statistical methods for assessing rater agreement in radiological studies.

Rater agreement is commonly assessed in radiologic studies concerning image quality. There are several methods of measuring rater agreement. To choose the appropriate method, the researcher needs to consider the scale of the outcome variable and the design of the study. This article provides a brief overview of available methods, focusing on the most practical and commonly used, including intraclass correlation, the Svensson method, variants of the kappa statistic, the agreement coefficient by Gwet (AC1/AC2), and Krippendorff's alpha. Additional methods that are not primarily intended for rater agreement analysis but are applied in some cases are also discussed.