Image perception

While it is not possible to specify in any general way how best to display clinical images, in recent years significant progress has been made in understanding the factors which determine the effectiveness of image presentation. The paper reviews the work on displaying medical images, in particular the relatively noisy images encountered in nuclear medicine and radiology. The need to present the relevant information in the image, in such a way that it is readily assimilated by the visual system, is central to the problem. A discussion of how the visual system may extract information from an image is followed by a review of models of the decision-making process. Standard psychophysical techniques allow the performance of the display to be measured subjectively. A summary is given of the results of such measurements on the effectiveness of different display techniques. The interpretation of the image may be aided by modifying the data prior to displaying it. A description is given of different filtering routines and of the work done to assess this success.