PET

Positron emission tomography (PET) is a medical examination method. It makes metabolic processes in body, thus providing information about tumours or inflammations.

How it works

Patients are injected with a weak radioactive substance, the tracer. This is usually glucose, which contains radioactive fluorine (1).

In spots with a high metabolic activity, such as tumours and inflammations, a lot of sugar is consumed. That's where the tracer accumulates (2).

The radioactive fluorine in the tracer decays. This produces photons that are measured by a detector. This can be used to calculate exactly where the tracer has accumulated and how much of it (3).

Characteristic

This is what a PET scan of the brain looks like. Standard PET devices measure with an accuracy of about 4 millimetres. More precise results can be obtained by combining PET with computed tomography (CT), an X-ray technique. Metabolic activity correlates with colour intensity

This text is published in the effzett issue 1-19. Illustrations: Diana Köhne

Never miss an issue of effzett again

Download latest issue and all issues in the archive as a PDF

Subscribe to free print edition and receive it by post