Positron emission tomography – computed tomography (PET/CT) is a medical imaging device which combines Positron Emission Tomography (PET) and an x-ray Computed Tomography (CT) in a single system. Images acquired from both devices can be taken sequentially, in the same patient and combined into a single superimposed image. Thus, functional imaging obtained by PET, which depicts the spatial distribution of metabolic or biochemical activity in the body can be more precisely aligned or correlated with anatomic imaging obtained by CT scanning. Form and function are thus visualized combining this anatomic and functional information data.
Precise localization of tracers in the body is very useful because it is normal to find the tracers in some organs/locations but not others. PET/CT primarily has applications in cancer, brain and heart imaging.