Positron emission tomography (PET) became after 25 years of its development a very important diagnostic method. In August 1999 the first PET centre in the Czech Republic was established at the Hospital Na Homolce. Although there is a similarity between PET and conventional nuclear medi- cine (scintigraphic imaging), there are certain features specific to PET. It is not only the physical background which results in different camera construction and technology of data acquiring but also methods of data reconstruction. This article presents the physical principles and technology of PET and demonstrates the procedure used at the PET centre Prague.

        Key words: PET - positron emission tomography - nuclear medicine