Optimization of gamma camera coincidence systems for PET in oncology

Abstract

H. Anger proposed the use of gamma camera detectors based on sodium iodide to register positron annihilation quanta as early as 1963. However, it took a relatively long time, until the year 1995, to develop tomographic imaging systems which were suited for routine applications [1]. In the few years since then, the performance of these systems has significantly risen, and their development has been predominantly aimed at improving the imaging quality of this PET variant. As a matter of fact, PET with gamma camera coincidence systems has now reached a level of performance which was hardly imaginable even a few years ago. The current imaging quality far surpasses that of the early dedicated PET scanners. This progress was made possible by advances in the design of digital gamma camera detectors as well as the availability of highly effective and fast signal processors. The performance of computers suited for complex tomographic reconstruction techniques has also risen considerably. When the first gamma camera coincidence systems for routine applications were introduced onto the market, it was apparent that the starting points of the manufacturers of such cameras were very different. Some of them focused their efforts on crystal thickness, others on signal processing or the application of transaxial septa. But these differing approaches were soon converging, optimizing tomographic resolution and providing easy system handling. Since the systems have become more alike, their imaging properties and clinical results are comparable.