In radiological practice the term recognition of detail is widely used. We examined how the term can be defined and interpreted, and how recognition of detail relates to radiological phantoms such as CDMAM (Contrast Detail Mammography). For tasks in visual perception a processing hierarchy can be assumed: The perception of a structure can occur at different processing levels, such as required in detection, discrimination, identification and recognition, with an ascending order of hierarchical relation. It is not always possible to predict from results at one hierarchy level those at another level. If an observer detects a structure, there is no prediction whether the observer will be able to discriminate the structure from another or whether he or she is even able to interpret the structure. Furthermore, the perceptibility of a detail is influenced by surrounding or overlapping anatomical noise. The presence of noise elevates visual thresholds and may change the overall perceptual behavior with regard to the examined parameter. Thus, perceptibility of structures (details ) is strongly bound to the type of perceptual task and the image background used. Speaking of recognition of detail should not liberally extended to evaluating performance parameters of a technical system. If the term is applied, it needs to be specified how detail is characterized and which perceptual task is used for operationalizing recognition.© (2009) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.