Abstract

This is a phenomenological study of the mental processes involved in the reading of Roentgen images. Its conceptual basis is in Roentgen semiotics, an adaptation of Peircean semiotics that incorporates the linguistic concept of markedness. It is shown that the notions of ‘abnormality’ and ‘change’ in Roentgen diagnosis are represented by signs of ‘difference.’ Differential signs for the detection, localization or identification of ‘abnormality’ or ‘change’ are constructed by means of Roentgen semiotic grammar.