[Principles of PET].

Positron emission tomography (PET) is a procedure in nuclear medicine, which is applied predominantly in oncological diagnostics. In the form of modern hybrid machines, such as PET computed tomography (PET/CT) and PET magnetic resonance imaging (PET/MRI) it has found wide acceptance and availability. The PET procedure is more than just another imaging technique, but a functional method with the capability for quantification in addition to the distribution pattern of the radiopharmaceutical, the results of which are used for therapeutic decisions. A profound knowledge of the principles of PET including the correct indications, patient preparation, and possible artifacts is mandatory for the correct interpretation of PET results.