The principle of hybrid imaging is a combination of originally independent examination methods into another modality. It has been found optimal to combine a method providing functional information with that providing anatomical and morphological information. In case of PET/CT, combination of positron emission tomography with computed tomography, PET provides information about tissue metabolism, and CT offers the anatomical-morphological image. In the diagnosis of lung processes PET/CT plays an indispensable role in the ability to establish a biological nature of focal pulmonary lesions, in the staging of malignant lung tumours and in the control of therapeutic effect of the selected therapeutic procedure. In view of a regular whole-body imaging there is an increased total sustained yield of the examination about diagnostics of extra-pulmonary lesions. A higher spatial resolution of CT increases sensitivity of PET itself and, on the contrary, the high specificity of PET examination in the diagnostics of morphological atypical lung processes contributes to specificity of CT itself. The combination of both methods into a single PET/CT modality contributes to increased sensitivity and specificity of both methods, decreased radiation load to the patient and shortened total diagnostic process. The most frequently used radiopharmacon in PET/CT diagnostics is 2-deoxy-2(18F)fluoro- D-glucose (FDG). The term FDG PET/CT is therefore frequently used in practice.

        Key words: positron emission tomography (PET) – computed tomography (CT) – fluorodeoxyglucose (FDG) – diagnostics – imaging