[Radiological expertise and diagnosis. I. Theoretical advances]. / Expertise et diagnostic radiologique. I. Avancées théoriques.

From the cognitive point of view, experts are characterized (1) by the ability to directly perceive large meaningful structures due to the development of numerous links within their knowledge networks, particularly between categories that, in manuals, are described as mutually exclusive (2) by the automation of diagnosis. Even in the best experts, some biases remain, mainly due to filters in facts and hypotheses selection. These filters are based upon the resemblance of the case with prior knowledge, and upon the likelihood of previous encountering similar cases. Biases are partially balanced by heuristics which are reasoning processes, valid for a majority of cases, but which induce some errors on atypical cases.

[Radiological expertise and diagnosis. II. Empirical study]. / Expertise et diagnostic radiologique. II. Etude empirique.

In order to study cognitive processes of radiological diagnosis, 22 radiologists with different experience levels interpreted two complex films, with no clinical data. Exploration strategies, used knowledge and reasoning were analyzed. Experimented radiologists interpreted clues more easily, using richer and more integrated knowledge. They used a symptomatic exploration, guided by hypotheses that related to salient cues. Cues that were both subtle and unexpected were better detected by novices and "super experts" than by intermediates and "basic experts". Novices detected those cues by mean of a systematic exploration. "Super experts" benefitted from an increased likelihood of unexpected cue detection due to longer and more supported reasoning. Also, they might have complemented the symptomatic exploration with an automatic systematic one.