Developments in Computerized Tomography Including Non-X-ray Techniques

Abstract

Computerized tomography (CT) employs a novel type of image buildup technique based on measured data obtained with a classic information carrier in the field of medicine, namely X-radiation. The rapid and impressive success attained by CT since its introduction in the first half of the 1970s has led to a number of attempts to combine its image reconstruction algorithm with other information carriers, most of which have also been tried and tested for medical applications, for example, the gamma radiation of nuclear-diagnostic indicators. To differentiate this from the “real” CT technique, namely roentgen (X-ray) CT, or RCT, we then speak of emission CT, or ECT. It is the aim of this article to provide an overview of such further cross-sectional imaging techniques with CT image reconstruction, the principle and the particular physical-technical problems receiving special attention. Furthermore, the attempt is also made — if only in outline — to assess the relevance and prospects of these techniques. Such an overview would also appear useful as background information for a discussion of the developmental tendencies in X-ray CT, since the knowledge and results gained with the other techniques might also be employed to advance the “real” or original (X-ray) CT technique.