ABSTRACT
The development of PET as an imaging modality sprang from the recognition that emissions from radioactive decay processes could be used to measure metabolic processes in vivo. The radioactive tracer method was ‰rst applied by George de Hevesy in 1923 for which he was awarded the Nobel Prize in Chemistry in 1943. The process of positron decay was discovered in 1933 by Thibaud (1933) and Joliot (1933) and within 12 years positron emitting radionuclides were being used to undertake metabolic studies in animals using O-15 (Tobias et al. 1945) and within 20 years the ‰rst images from studies in man using coincidence detection were published (Anger and Gottschalk 1963). In these early years the potential and role of positron emitting radionuclides was formed. Radionuclides of carbon, C-11, nitrogen, N-13, oxygen, O-15 and ´uorine, F-18 were produced and integrated in biologically active molecules to trace biochemical pathways and reactions. The desire for quanti‰cation was paramount and the application of coincidence detection of positron emissions provides the basis for the realisation of this goal today. Over the ensuing period a broad range of technological advances have occurred and this has led to the transition of PET from the research laboratory to a routine clinical imaging tool.
